Service Manual2005 ANTILOCK BRAKE SYSTEM

SECTION 4F

ANTILOCK BRAKE SYSTEM

Caution : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.

SPECIFICATIONS

General Specifications

Application	Unit	Description
Antilock Brake System (ABS) Mode	-	4 Channel 4 Sensor
ABS Main Relay Operation Voltage	V	9~16
Wheel Speed Sensor : Resistance	Ω	1,040~1,161
Speed Ring	-	-
Outside Diameter (Front)	mm (inch)	70.4 (2.7716)
Outside Diameter (Rear)	mm (inch)	41.13 (1.6192)
Inside Diameter (inch)	mm (inch)	61.9 (2.4370)
Inside Diameter (Rear)	mm (inch)	28.1 (1.1063)
Tooth Volume of the Speed Ring	EA	47
Brake Oil	-	-
Type	-	DOT-3
Capacity	L (qt.)	0.382

Fastener Tightening Specifications

Application	N•m	Lb-Ft	Lb-In
Brake Pipe Fitting Nut (Hydraulic Unit)	16	12	-
ABS Mounting Bracket Bolt	22	16	-

SCHEMATIC AND ROUTING DIAGRAMS

Abs System Circuit (I)

Abs System Circuit (II)

Electrical Schematic (I) - ABS

Electrical Schematic (II) - ABS with FTCS (Full - function TCS)

HECU Harness Connector end View and Pin Layout

ABS (Export) Pin Assignments

Pin Location	Circuit Function
1	RIGHT FRONT WHEEL SPEED SENSOR
2	RIGHT FRONT WHEEL SPEED SENSOR
3	WHEEL SPEED SIGNAL TO ECM (ENGINE CONTROL MODULE)
4	IGNITION
.	.
5	LEFT FRONT WHEEL SPEED SENSOR
6	LEFT FRONT WHEEL SPEED SENSOR
7	DIAGNOSTIC
8	GROUND (G104)
9	BATTERY (HECU MOTOR)
10	CAN (Low)
11	CAN (High)
12	TCS OFF LAMP
.	.
13	-
14	TCS SWITCH
15	-
.	.
16	ABS/EBD WARNING LAMP OUTPUT
17	TCS WARNING LAMP
18	STOP LAMP SWITCH INPUT
19	LEFT FRONT WHEEL SPEED SENSOR
20	LEFT FRONT WHEEL SPEED SENSOR
21	TCS ACTIVE LAMP
22	RIGHT REAR WHEEL SPEED SENSOR
23	RIGHT REAR WHEEL SPEED SENSOR
24	GROUND (G104)
25	BATTERY (SOLENOID VALVE)

Hydraulic Diagram

MCP : Master Cylinder Primary

MCS : Master Cylinder Secondary

NO : Normal Open Solenoid Valve

NC : Normal Close Solenoid Valve

M : Electric Motor

LPA : Low Pressure Accumulator

HPA : High Pressure Accumulator

COMPONENT LOCATOR

ABS System

Hydraulic Electronic Control Unit
Front Wheel Speed Sensor
Rear Wheel Speed Sensor

DIAGNOSIS

Diagnostic Trouble Code AND Description

DTC	Decsription	Check Point (Value)
C1101	Battery voltage too high	16V or higher
C1102	Battery voltage too low	9.4V or lower
C1200	Left front wheel speed sensor circuit open or shorted	Sensor, Wiring Harness, Connector
C1201	Left front wheel speed excessive variation	Sensor, Wiring Harness, Connector, Airgap
C1202	Left front wheel speed sensor no signal	Sensor, Wiring Harness, Connector, Airgap, HECU*
C1203	Right front wheel speed sensor circuit open or shorted	Sensor, Wiring Harness, Connector
C1204	Right front wheel speed excessive variation	Sensor, Wiring Harness, Connector, Airgap
C1205	Right front wheel speed sensor no signal	Sensor, Wiring Harness, Connector, Airgap, HECU
C1206	Left rear wheel speed sensor circuit open or shorted	Sensor, Wiring Harness, Connector
C1207	Left rear wheel speed excessive variation	Sensor, Wiring Harness, Connector, Airgap
C1208	Left rear wheel speed sensor no signal	Sensor, Wiring Harness, Connector, Airgap, HECU
C1209	Right rear wheel speed sensor circuit open or shorted	Sensor, Wiring Harness, Connector
C1210	Right rear wheel speed excessive variation	Sensor, Wiring Harness, Connector, Airgap
C1211	Right rear wheel speed sensor no signal	Sensor, Wiring Harness, Connector, Airgap, HECU
C1503	TCS Switch Error	TCS Switch, Connector, Wiring Harness
C1604	HECU internal fault	HECU
C1605	CAN Hardware Error	HECU, Connector
C1611	CAN time - out EMS	HECU, Connector
C1612	CAN time - out TCU	HECU, Connector
C1616	CAN bus off	HECU, Connector
C2112	Valve relay or fuse failure	Fuse, HECU
C2380	ABS / TCS Valve error	HECU, Connector
C2402	Pump motor failure	Motor, Fuse, Connector

* HECU : Hydraulic Electronic Control Unit

Diagnostic Circuit Check

System Description

The Diagnostic Circuit Check is an organized method of identifying any problems caused by a malfunction in the ABS/DDRP system.

A service technician should begin diagnosis of any ABS/DDRP complaint with the Diagnostic Circuit Check. The Diagnostic Circuit Check directs a service technician to the next logical step when diagnosing a complaint.

Serial Data is transmitted/received by the HECU through terminal 7. The HECU is supplied with constant battery feed voltage through terminals 9 and 25, and switched ignition voltage through terminal 4. The HECU ground is provided through terminal 8 and 24.

Diagnostic Process

Use the following ordered procedure when servicing the ABS/DDRP system.

Inspect the vehicle for any mechanical conditions related the brake system.

Brake reservoir fluid level correct.
Inspect master for fluid for contamination.
Inspect brake master/modulator for leaks.
Inspect brake master/modulator for leaks.
Inspect brake components at all wheels.
Verify no brake drag exists (brake switch adjustment).
Verify even brake apply (no pull or lead).
Inspect for worn/damaged brake pads.
Inspect for worn/damaged wheel bearings
Inspect wheel speed sensors/wiring.
Inspect exciter rings for damage
Inspect tires for tread depth/wear.
Road test the vehicle to verify the complaint

Perform the Diagnostic Circuit Check and proceed to the applicable Diagnostic Trouble Chart as necessary.
Clear the ABS DTCs (Diagnostic Trouble Codes) after all of the system malfunctions have been corrected.

Diagnostic Circuit Check

Step	Action	Value(s)	Yes	No
1	Connect or install all previously disconnected or removed components if applicable. Ignition switch "ON" Install the applicable Scan Tool into the DLC and attempt to communicate with the HECU. Does the Scan Tool communicate with the HECU?	-	Go to Step 2	Go to Step 4
2	Were any DTC(s) stored current or history?	-	Go to Step 3	Go to Step 7
3	Document Current DTC(s). Document History DTC(s). Document Enhanced History Data such as number of times each DTC set. number of times since each DTC first set. number of times each DTC set. speed when each DTC set. other Enhanced Data which may assist with diagnosis. Do not clear DTC(s) prior to fully documenting the information from the scan tool. Refer to the applicable Diagnostic Trouble Code(s).	-	Go to the table for the DTC(s)	-
4	Does the Scan Tool communicate with other Modules on the data line?	-	Go to Step 5	Go to Step 6
5	Go to the no communication with HECU with HECU trouble chart.	-	Go to "No Communication with HECU"	System OK
6	Repair the DLC harness. Replace the DLC harness as needed.	-	System OK	-
7	Ignition switch "OFF" Wait 10 seconds. Ignition switch "ON" Observe the amber ABS lamp when the key is turned on. Did the ABS Warning Lamp and Brake Warning Lamp turn on for 3 seconds and then turn off? (bulb test)	-	Go to Step 8	Go to Step 9
8	System functioning as designed.	-	System OK	-
9	Did the any lamp stay on?	-	Go to Step 10	Go to Step 11
10	Go to appropriate lamp "ON" trouble chart.	-	-	-
11	Go to appropriate lamp "INOPERATIVE" trouble chart	-	-	-

No Communication with HECU

Circuit Description

Diagnostic Aids

Typical causes of no communication with the HECU.

Poor terminal contact at the HECU.
Loss of HECU ground to terminal 8 and 24
Loss of battery voltage at HECU terminals 9 and or 25.
Loss of ignition voltage at HECU 4.
Open/grounded data line.
Data line with high resistance.

No Communication with HECU

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check Performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find problem?	-	Go to Step 3	System OK
3	Ignition switch "OFF" Disconnect the HECU harness. Connect a voltmeter to HECU harness terminal 9 and then to body ground. Was the voltage within the specified range?	Battery Voltage	Go to Step 5	Go to Step 4
4	Repair the source of low voltage to terminal 9. Inspect for an open fuse, poor terminal contact, or a grounded wire.	-	System OK	-
5	Connect a voltmeter to HECU harness terminal 25 and then to body ground. Was the voltage within the specified range?	Battery Voltage	Go to Step 7	Go to Step 6
6	Repair the source of low voltage to terminal 25. Inspect for an open fuse, poor terminal contact, or a grounded wire.	-	System OK	-
7	Ignition switch "ON" Connect a voltmeter to HECU harness terminal 4 and then to body ground. Was the voltage within the specified range?	Battery Voltage	Go to Step 9	Go to Step 8
8	Repair the source of low voltage to terminal 4. Inspect for an open fuse, poor terminal contact, or a grounded wire.	-	System OK	-
9	Ignition switch "OFF" Connect a voltmeter to HECU harness terminal 8 and 24 and then to body ground. Was the voltage within the specified range?	Less than 2 ohms	Go to Step 11	Go to Step 10
10	Repair the source of high resistance between terminal 8 and 24 and body ground. Find and check the ground location where the circuit is secured to body ground.	-	System OK	-
11	Ignition switch "OFF" HECU harness still disconnected from the HECU. Connect an ohmmeter to HECU harness terminal 7 and DLC terminal 7. Was the voltage within the specified range?	Less than 2 ohms	Go to Step 13	Go to Step 12
12	Repair the source of high resistance between terminal 7 and DLC terminal 7.	-	System OK	-
13	Ignition switch "OFF" HECU harness still disconnected. Connect an ohmmeter to HECU harness terminal 7 and then to body ground. Was the voltage within the specified range?	OL (open circuit)	Go to Step 15	Go to Step 14
14	Find and repair the short to ground on the data line.	-	System OK	-
15	Replace the HECU.	-	System OK	-

ABS Warning Lamp Inoperative/No DTC Set

Circuit Description

The Hydraulic Electronic Control Unit (HECU) controls the operation of the amber ABS Warning Lamp by means of a lamp driver module contained within the Cluster.

Battery voltage is supplied to the I/P Cluster terminal B14, and HECU terminal 4 when the ignition switch is turned on. HECU terminals 9 and 25 are 'hot at all times'.

The default state is for the Lamp Driver Module to turn ON the amber ABS Warning Lamp, by supplying a ground path through the Lamp Driver Module.

When the HECU commands the ABS lamp off, the HECU will ground the ABS Warning Lamp control circuit. This causes the Lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the HECU turns ON the ABS Warning Lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the ABS system, the HECU turns ON the ABS Warning Lamp, notifying the driver that ABS needs to be serviced.

Diagnostic Aids

Typical causes of the ABS warning lamp inoperative with no DTC(s) set.

Faulty ABS bulb/ loose socket.
I/P fuse open.
Faulty Cluster/Lamp Driver Module.
Faulty HECU.
Grounded circuit between the HECU and the Cluster.
Grounded circuit between the HECU and the Cluster.

ABS Warning Lamp Inoperative/No DTC Set

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find problem	-	Go to Step 3	System OK
3	Disconnect the HECU harness from the HECU. Key on. Did the amber ABS lamp turn on?	-	Go to Step 4	Go to Step 5
4	Replace the HECU.	-	System OK	-
5	Check the Cluster fuse. Is the fuse and terminal contact ok?	-	Go to Step 7	Go to Step 6
6	Replace the open fuse and/or repair the loose terminals. Find the short, which caused the fuse to open, if applicable.	-	System OK	-
7	Remove the amber ABS bulb from the Cluster and inspect for an open bulb filament or poor socket contact? Was the socket and bulb ok?	-	Go to Step 9	Go to Step 8
8	Replace the Bulb/Socket as needed.	-	System OK	-
9	Ignition switch "OFF". HECU harness still disconnected. Remove the Cluster Assembly from the Instrument Panel. Disconnect the white Cluster harness connector from the Cluster Assembly. Ignition switch "ON". Connect a voltmeter to terminal B14 of the Cluster harness and then to body ground. Was the voltage within the specified range?	Battery Voltage	Go to Step 11	Go to Step 10
10	Find and repair the source of low voltage on the cluster voltage supply terminal.	-	System OK	-
11	Ignition switch "OFF". Disconnect the White Cluster harness connector from the Cluster Assembly. Connect an ohmmeter between the Cluster harness terminal A14 and ABS Warning Lamp Module terminal 6. Was the resistance within the specified range?	Less than 2 ohms	Go to Step 13	Go to Step 12
12	Repair the open or high resistance between the cluster and the ABS Warning Lamp Module.	-	System OK	-
13	Ignition switch "OFF". ABS Warning Lamp Module harness and HECU harness still disconnected. Connect an ohmmeter to HECU harness terminal 16 and then to body ground. Was the resistance within the specified range?	OL (open circuit)	Go to Step 15	Go to Step 14
14	Find the repair the short to ground between the Cluster harness and the HECU harness.	-	System OK	-
15	Replace the ABS Warning Lamp Module. Is the repair complete?	-	System OK	Go to Step 16
17	Replace the Cluster Assembly.	-	System OK	-

ABS Warning Lamp On/No DTC Set

Circuit Description

The Hydraulic Electronic Control Unit (HECU) controls the operation of the amber ABS Warning Lamp by means of a lamp driver module contained within the Cluster.

Battery voltage is supplied to the I/P Cluster terminal B14, and HECU terminal 4 when the ignition switch is turned on. HECU terminals 9 and 25 are `hot at all times'.

The default state is for the Lamp Driver Module to turn ON the amber ABS lamp, by supplying a ground path through the Lamp Driver Module.

When the HECU commands the ABS lamp off, the HECU will ground the ABS Warning Lamp control circuit. This causes the Lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the HECU turns ON the ABS Warning Lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the ABS system, the HECU turns ON the ABS Warning Lamp, notifying the driver that ABS needs to be serviced.

Diagnostic Aids

Typical causes of the ABS warning lamp on with no DTC(s) set.

Grounded circuit between the Cluster and the HECU.
Faulty Cluster/Lamp Driver Module.
Faulty HECU.

ABS Warning Lamp On/No DTC Set

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find problem?	-	Go to Step 3	System OK
3	Ignition switch "OFF". Disconnect the HECU harness from the HECU. Ignition switch "ON". Connect a fused jumper wire between terminal 16 of the HECU harness and body ground. Did the amber ABS lamp turn off?	-	Go to Step 4	Go to Step 5
4	Replace the HECU.	-	System OK	-
5	Ignition switch "OFF". Remove the Cluster Assembly from the I/P. Disconnect the white Cluster harness connector from the Cluster Assembly. Disconnect the ABS Warning Lamp Module harness connector from the ABS Warning Lamp Module. Connect an ohmmeter to cluster harness terminal A14 and then to body ground. Was the resistance within the specific range?	OL (open circuit)	Go to Step 7	Go to Step 6
6	Find the repair the short to ground between the Cluster harness and the ABS Warning Lamp Module harness.	-	System OK	-
7	Ignition switch "OFF". Disconnect the HECU harness from the HECU. Disconnect the ABS Warning Lamp Module harness from the ABS Warning Lamp Module. Connect an ohmmeter to terminal D of the ABS Warning Lamp Module harness and then to HECU harness terminal 16. Was the resistance within the specific range?	Less than 2 ohms	Go to Step 9	Go to Step 8
8	Repair the open or high resistance between the ABS Warning Lamp Module and the HECU.	-	System OK	-
9	Replace the ABS Warning Lamp Module. Is the repair complete?	-	System OK	Go to Step 10
10	Replace the Cluster Assembly.	-	System OK	-

Brake Warning Lamp On

Circuit Description

The Hydraulic Electronic Control Unit (HECU) controls the operation of the Brake Warning Lamp by means of a lamp driver module contained within the Cluster.

Battery voltage is supplied to the I/P Cluster terminal B14, and HECU terminal 4 when the ignition switch is turned on HECU terminals 9 and 25 are `hot at all times'

The default state is for the Lamp Driver Module to turn ON the Brake Warning Lamp, by supplying a ground path through the Lamp Driver Module.

When the HECU commands the Brake Warning Lamp off, the HECU will ground the ABS Warning Lamp control circuit. This causes the Lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the HECU turns ON the Brake Warning Lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the general brake system or MANDO MGH25 ABS system, the HECU may turn ON the Brake Warning Lamp, notifying the driver that either Brake System or MGH25 needs to be serviced.

Diagnostic Aids

Typical causes of the Brake Warning Lamp on with no DTC(s) set

Faulty Emergency brake switches.
Low brakes fluid level or faulty brake fluid switch.
DDPR is disabled due to the following fault conditions in MGH25 ABS system.

Two Wheel Speed Sensors inoperative on same axle.

Battery 2(Motor Input) short to ground.

Battery 1(ECU Input) Open or short to ground.

Motor ground open or short to battery.

ECU ground open or short to battery.

Ignition open or short to ground.

Grounded circuit between the Cluster and the HECU.
Faulty Cluster/Lamp Driver Module.
Faulty HECU.

Brake Warning Lamp On

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find problem?	-	Go to Step 3	System OK
3	Observe ABS Warning Lamp. Does ABS Warning Lamp ON also?	-	Go to Step 5	Go to Step 4
4	Possibility of general brake system failure. Repair the brake system.	-	System OK	-
5	Connect Scan Tool and retrieve DTC. Did DTC exist?	-	Go to Step 6	Go to Step 7
6	Go to appropriate DTC diagnostic section.	-	System OK	-
7	Ignition switch "OFF". Disconnect the HECU harness from the HECU. Ignition switch "ON". Connect a fused jumper wire between terminal 16 of the HECU harness and body ground. Did the Brake Warning Lamp turn off?	-	Go to Step 8	Go to Step 9
8	Replace the HECU.	-	System OK	-
9	Ignition switch "OFF". Remove the Cluster Assembly from the I/P. Disconnect the white Cluster harness connector from the Cluster Assembly. Disconnect the ABS Warning Lamp Module harness connector from the ABS Warning Lamp Module. Connect an ohmmeter to cluster harness C2 and then to body ground. Was the resistance within the specific range?	OL (open circuit)	Go to Step 11	Go to Step 10
10	Find the repair the short to ground between the Cluster harness and the ABS Warning Lamp Module harness.	-	System OK	-
11	Ignition switch "OFF". ABS Warning Lamp Module harness and HECU harness still disconnected Connect an ohmmeter to terminal D of the ABS Warning Lamp Module harness and then to HECU harness terminal 16. Was the resistance within the specific range?	Less than 2 ohms	Go to Step 13	Go to Step 12
12	Repair the open or high resistance between the ABS Warning Lamp Module and the HECU.	-	System OK	-
13	Replace the ABS Warning Lamp Module. Is the repair complete?	-	System OK	Go to Step 14
14	Replace the Cluster Assembly.	-	System OK	-

Brake Warning Lamp Inoperative/No DTC Set

Circuit Description

The Hydraulic Electronic Control Unit (HECU) controls the operation of the red Brake Warning Lamp by means of a lamp driver module contained within the Cluster.

Battery voltage is supplied to the I/P Cluster terminal B14, and HECU terminal 4 when the ignition switch is turned on HECU terminals 9 and 25 are `hot at all times'

When the HECU commands the Brake Warning lamp off, the HECU will ground the Brake Warning Lamp control circuit. This causes the Lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the HECU turns ON the Brake Warning Lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the General Brake system or DDRP, the HECU turns ON the Brake Warning Lamp, notifying the driver that Brake System or DDRP needs to be serviced.

Diagnostic Aids

Typical causes of the Brake Warning Lamp inoperative with no DTC(s) set.

Faulty bulb/ loose socket.
I/P fuse open.
Faulty Cluster/Lamp Driver Module.
Faulty HECU.
Grounded circuit between the HECU and the Cluster.

Brake Warning Lamp Inoperative/No DTC Set

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find problem?	-	Go to Step 3	System OK
3	Disconnect the HECU harness from the HECU. Ignition switch "ON". Did the Brake Warning Lamp turn on?	-	Go to Step 4	Go to Step 5
4	Replace the HECU.	-	System OK	-
5	Check the Cluster fuse. Is the fuse and terminal contact ok?	-	Go to Step 7	Go to Step 6
6	Replace the open fuse and/or repair the loose terminals. Find the short, which caused the fuse to open, if applicable.	-	System OK	-
7	Remove the Brake Warning Lamp bulb from the Cluster and inspect for an open bulb filament or poor socket contact? Was the socket and bulb ok?	-	Go to Step 9	Go to Step 8
8	Replace the Bulb/Socket as needed.	-	System OK	-
9	Ignition switch "OFF". HECU harness still disconnected. Remove the Cluster Assembly from the Instrument Panel. Disconnect the white Cluster harness connector from the Cluster Assembly. Ignition switch "ON". Connect a voltmeter to terminal B14 of the Cluster harness and then to body ground.. Was the voltage within the specified range?	Battery Voltage	Go to Step 11	Go to Step 10
10	Find and repair the source of low voltage on the cluster voltage supply terminal.	-	System OK	-
11	Ignition switch "OFF". Disconnect the White Cluster harness connector from the Cluster Assembly. Connect an ohmmeter between the Cluster harness terminal C2 and ABS Warning Lamp Module harness terminal 3. Was the resistance within the specific range?	Less than 2 ohms	Go to Step 13	Go to Step 12
12	Repair the open or high resistance between the cluster and the ABS Warning Lamp Module.	-	System OK	-
13	Ignition switch "OFF". ABS Warning Lamp Module harness and HECU harness still disconnected Connect an ohmmeter to HECU harness terminal 16 and then to body ground.. Was the resistance within the specific range?	OL (open circuit)	Go to Step 15	Go to Step 14
14	Find the repair the short to ground between the ABS Warning Lamp Module harness and the HECU harness	-	System OK	-
15	Replace the ABS Warning Lamp Module. Is the repair complete?	-	System OK	Go to Step 16
16	Replace the Cluster Assembly.	-	System OK	-

TCS Active Lamp Inoperative/No DTC Set

Circuit Description

The Electronic Brake Control Module(EBCM) controls the operation of the TCS active lamp. Battery voltage is supplied to the I/P Cluster terminal B14 when the ignition switch is turned on EBCM terminals 9 and 25 are ‘hot at all times’.

When the EBCM commands the TCS active lamp off, the EBCM will ground the TCS active lamp control circuit. This causes the lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the EBCM turns ON the TCS active lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the general brake system or DDRP, the EBCM turns ON the TCS active lamp, notifying the driver the brake system or DDRP needs to be serviced.

Diagnostic Aids

Typical causes of the TCS active Lamp inoperative with no DTC(s) set are as following.

Faulty ABS warning lamp bulb/loose socket.
F12 fuse open.
Faulty EBCM.
Grounded circuit between the EBCM and the Cluster.

TCS Active Lamp Inoperative/No DTC Set

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find any problem?	-	Go to Step 3	System OK
3	Ignition switch “OFF”. Disconnect the EBCM wiring harness connector. Ignition switch “ON”. Connect the 21 terminal of the EBCM wiring harness connector and body ground with a jump wire. Is the TCS Active lamp turn ON?	-	Go to Step 4	Go to Step 5
4	Replace the EBCM. Check the Diagnostic Circuit.	-	-	-
5	Ignition switch “OFF”. Remove the cluster. Check the resistance between 21 terminal of the EBCM wiring harness connector and A16 terminal of the cluster wiring harness connector. Is the resistance under 2 ohoms?	< 2 ohoms	Go to Step 7	Go to Step 6
6	Repair the wiring harness.	-	-	-
7	Replace the cluster or the bulb.	-	-	-

TCS Active Lamp On

Circuit Description

When the EBCM commands the TCS active lamp off, the EBCM will ground the TCS active lamp control circuit. This causes the lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the EBCM turns ON the TCS active lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the general brake system or DDRP, the EBCM turns ON the TCS active lamp, notifying the driver the brake system or DDRP needs to be serviced.

Diagnostic Aids

Typical cause of the TCS active Lamp ON with no DTC(s) set is mainly EBCM wiring harness short to battery.

TCS Indicator Lamp On

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find any problem?	-	Go to Step 3	System OK
3	Ignition switch “OFF”. Disconnect the EBCM wiring harness connector. Ignition switch “ON”. Is the TCS active lamp turned OFF?	-	Go to Step 4	Go to Step 5
4	Replace the EBCM. Check the Diagnostic Circuit.	-	-	-
5	Ignition switch “OFF”. Remove the cluster. Ignition switch “ON”. Check the voltage between A16 terminal of the cluster wiring harness connector and body ground. Is the voltage under 0.1V ?	< 0.1V	Go to Step 7	Go to Step 6
6	Repair the short of wiring harness and battery.	-	-	-
7	Replace the cluster or the bulb.	-	-	-

TCS Warning Lamp Inoperative/No DTC Set

Circuit Description

The Electronic Brake Control Module(EBCM) controls the operation of the TCS warning lamp. Battery voltage is supplied to the I/P Cluster terminal B14 when the ignition switch is turned on EBCM terminals 9 and 25 are ‘hot at all times’.

When the EBCM commands the TCS warning lamp off, the EBCM will ground the TCS warning lamp control circuit. This causes the lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the EBCM turns ON the TCS warning lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the general brake system or DDRP, the EBCM turns ON the TCS warning lamp, notifying the driver the brake system or DDRP needs to be serviced.

Diagnostic Aids

Typical causes of the TCS warning Lamp inoperative with no DTC(s) set are as following.

Faulty ABS warning lamp bulb/loose socket.
F12 fuse open.
Faulty EBCM.
Grounded circuit between the EBCM and the Cluster.

TCS Warning Lamp Inoperative/No DTC Set

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find any problem?	-	Go to Step 3	System OK
3	Ignition switch “OFF”. Disconnect the EBCM wiring harness connector. Ignition switch “ON”. Connect the 17 terminal of the EBCM wiring harness connector and body ground with a jump wire. Is the TCS warning lamp turn ON?	-	Go to Step 4	Go to Step 5
4	Replace the EBCM. Check the Diagnostic Circuit.	-	-	-
5	Ignition switch “OFF”. Remove the cluster. Check the resistance between 17 terminal of the EBCM wiring harness connector and A13 terminal of the cluster wiring harness connector. Is the resistance under 2 ohoms?	< 2 ohoms	Go to Step 7	Go to Step 6
6	Repair the short of wiring harness and battery.	-	-	-
7	Replace the cluster or the bulb.	-	-	-

TCS Warning Lamp On

Circuit Description

When the EBCM commands the TCS warning lamp off, the EBCM will ground the TCS warning lamp control circuit. This causes the lamp Driver Module to open the path to ground for the bulb.

When the ignition switch is turned to the ON position, the EBCM turns ON the TCS warning lamp for 3 seconds for a bulb check.

Whenever a malfunction is detected within the general brake system or DDRP, the EBCM turns ON the TCS lamp, notifying the driver the brake system or DBC7 needs to be serviced.

Diagnostic Aids

Typical cause of the TCS warning Lamp ON with no DTC(s) set is mainly EBCM wiring harness short to battery.

TCS Warning Lamp On

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic Circuit Check performed?	-	Go to Step 3	Go to Step 2
2	Perform the Diagnostic Circuit Check. Did you find any problem?	-	Go to Step 3	System OK
3	Ignition switch “OFF”. Disconnect the EBCM wiring harness connector. Ignition switch “ON”. Is the TCS warning lamp turned OFF?	-	Go to Step 4	Go to Step 5
4	Replace the EBCM. Check the Diagnostic Circuit.	-	-	-
5	Ignition switch “OFF”. Remove the cluster. Ignition switch “ON”. Check the voltage between A13 terminal of the cluster wiring harness connector and body ground. Is the voltage under 0.1V ?	< 0.1V	Go to Step 7	Go to Step 6
6	Repair the short of wiring harness and battery.	-	-	-
7	Replace the cluster or the bulb.	-	-	-