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Diagnostic Trouble Code (DTC) P0420

Catalyst Oxygen Sensor Low Efficiency

Circuit Description

In order to control exhaust emissions of Hydrocarbons (HC), Carbon Monoxide (CO) and Nitrogen Oxide (NOx), a Three-Way Catalytic Converter (TWC) is used. The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas, converting them into harmless water vapor and carbon dioxide, it also reduces NOx, converting it into nitrogen. The catalytic converter also has the ability to store oxygen. The Engine Control Module (ECM) has the capability to monitor this process using a Heated
Rear Heated Oxygen Sensor (HO2S2) located in the exhaust stream past the TWC. The HO2S2 produces an output signal which indicates the oxygen storage capacity of the catalyst; this in turn indicates the catalyst's ability to convert exhaust emissions effectively. The ECM monitors the catalyst efficiency by first allowing the catalyst to heat up, waiting for a stabilization period while the engine is idling, and then adding and removing fuel while monitoring the reaction of the HO2S2. When the catalyst is functioning properly, the HO2S2 response to the extra fuel is slow compared to the Front Heated Oxygen Sensor (HO2S1). When the HO2S2 response is close to that of the HO2S1, the Oxygen storage capability or efficiency of the catalyst is considered to be bad, and the Malfunction Indicator Lamp (MIL) will illuminate.

Conditions for Setting the DTC

Note : Test is aborted for this idle if:

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

The catalyst test may abort due to a change in the engine load. Do not change the engine load (i.e. A/C, coolant fan, heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor connection, rubbed-through wire insulation, or a wire that is broken inside the insulation.
Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for the following conditions:

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.
  1. The On-Board Diagnostic (EOBD) System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
  2. If any component DTCs are set, diagnose those DTCs first. A fault in a component can cause the converter to appear degraded or may have caused its failure.
  3. This step includes checks for conditions that can cause the three-way catalytic converter to appear degraded. Repair any problems found before proceeding with this table.
  4. If the three-way catalytic converter needs to be replaced, make sure that another condition is not present which would cause the converter to become damaged. These conditions may include the following: misfire, high engine oil or coolant consumption, and/or retarded spark timing or weak spark. To avoid damaging the replacement converter, correct any possible causes of converter damage before replacing the catalytic converter.
  5. Clearing DTCs allows the catalyst test to be run up to 6 times this ignition cycle. Once the ignition is cycled, the test will run only once. Driving the vehicle heats the catalyst to a test temperature. The ECM must see predetermined amount of time at above idle before allowing the catalyst test to run at idle. Once at idle, the ECM will allow the system to stabilize and then test the catalyst in 2 stages.
  6. If no faults have been found at this point and no additional DTCs were set, refer to "Diagnostic Aids" in this section for additional checks and information.

DTC P0420 - Catalyst Oxygen Sensor Low Efficiency

Step Action Value(s) Yes No
1
Perform an On-Board Diagnostic (EOBD) System Check.
Was the check performed?
-
Go to Step 2
Go to "On-Board Diagnostic System Check"
2
  • Install a scan tool to the Data Link Connector (DLC).
  • Turn the ignition ON.
Are any component Diagnostic Trouble Codes (DTCs) set?
-
Go to applicable DTC tables
Go to Step 3
3
Visually/physically check the following:
  • Exhaust system for a leak.
  • Rear Heated Oxygen Sensor (HO2S2)
Is a problem found?
-
Go to Step 4
Go to Step 5
4
Repair the exhaust system as needed.
Is the repair complete?
-
Go to Step 6
-
5
Replace the Three Way Catalytic Converter (TWC).
Is the repair complete?
-
Go to Step 6
-
6
  1. Using the scan tool, clear the Diagnostic Trouble Codes (DTCs).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the vehicle within the Conditions for setting this DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic has run and passed?
-
Go to Step 7
Go to Step 2
7
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?
-
Go to applicable DTC table
System OK

V3B11F53
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Diagnostic Trouble Code (DTC) P0443

Evaporative Emission System Purge Solenoid Control Circuit

System Description

The Evaporative Emission (EVAP) system includes the following components:
The EVAP purge canister solenoid is controlled by the Engine Control Module (ECM). The ECM applies a ground to the EVAP purge canister solenoid. The ECM determines when to activate the EVAP canister purge solenoid depending on operating conditions, including Throttle Position (TP), engine speed, Engine Coolant Temperature (ECT) and ambient temperature.
The Diagnostic Trouble Code will detect an open or short circuit.

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and the Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (rpm, load, vehicle speed, temperature, etc.) that were noted. This will isolate when the DTC failed.

DTC P0443 - Evaporative Emission System Purge Solenoid Control Circuit

Step Action Value(s) Yes No
1
Perform an On-Board Diagnostic (EOBD) System Check.
Was the check performed?
-
Go to Step 2
Go to "On-Board Diagnostic System Check"
2
  1. Install a scan tool to the Data Link Connector (DLC).
  2. Turn the ignition ON.
  3. Command the Evaporative Emission (EVAP) Purge Solenoid ON and OFF.
Does the solenoid turn ON and OFF with each command.
ON-99%
OFF-0%
Go to Step 3
Go to Step 5
3
  1. Turn the ignition OFF.
  2. Disconnect the Engine Control Module (ECM) connector.
  3. Turn the ignition ON.
  4. Using a ammeter on a 10 ampere scale, measure the current between the solenoid control circuit, terminal M4 at the ECM connect and ground for 2 minutes.
Does the current draw measure less than the specified value?
0.75 A
Go to "Diagnostic Aids"
Go to Step 4
4
  1. Disconnect the solenoid.
  2. Using ohmmeter measure the resistance between the solenoid control circuit, terminal M4 of the ECM connector and ground.
Does the ohmmeter display infinite resistance?
-
Go to Step 12
Go to Step 10
5
  1. Turn the ignition OFF.
  2. Disconnect the solenoid.
  3. Connect a test light between the terminal 2 and 1 of the solenoid.
  4. Turn the ignition ON.
  5. Using the scan tool, command the solenoid ON and OFF.
Does the test light turn ON and OFF with each command?
-
Go to Step 8
Go to Step 6
6
With a test light connected to ground, probe the ignition feed circuit, terminal 2 in the solenoid harness connector.
-
Go to Step 7
Go to Step 11
7
  1. Turn the ignition OFF.
  2. Reconnect the solenoid.
  3. Disconnect the ECM connector.
  4. Turn the ignition ON.
  5. With a fused jumper wire connected to ground, probe the solenoid control circuit terminal M4 in the ECM connector.
Does the solenoid operate?
-
Go to Step 9
Go to Step 10
8
Check the connections at the solenoid.
Is a problem found and corrected?
-
Go to Step 14
Go to Step 12
9
Check the connections at the ECM.
Is a problem found and corrected?
-
Go to Step 14
Go to Step 13
10
Repair the faulty solenoid control circuit.
Is the repair complete?
-
Go to Step 14
-
11
Repair the faulty solenoid ignition feed circuit.
Is the repair complete?
-
Go to Step 14
-
12
  1. Turn the ignition OFF.
  2. Replace the solenoid.
Is the repair complete?
-
Go to Step 14
-
13
  1. Turn the ignition OFF.
  2. Replace ECM.
Is the repair complete?
-
Go to Step 14
-
14
  1. Using the scan tool, clear the Diagnostic Trouble Codes (DTCs).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the vehicle within the Conditions for setting this DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic has run and passed?
-
Go to Step 15
Go to Step 2
15
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?
-
Go to applicable DTC table
System OK

V4B11F15
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Diagnostic Trouble Code (DTC) P0461

Fuel Level Stuck

Circuit Description

The Engine Control Module (ECM) uses the signal from the fuel level sensor to calculate expected vapor pressure within the fuel system. Vapor pressure varies as the fuel level changes. The fuel level signal also used to determine if the fuel level is too high or too low to be able to detect Evaporative Emission (EVAP) system faults. This Diagnostic Trouble Code (DTC) indicates the fuel level stuck.

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the rubber.
Check for a poor connection or damaged ECM harness. Inspect the fuel level circuit terminal for the following conditions:

Test Description

The number(s) below refer to step(s) on the diagnostic table.
  1. The On-Board Diagnostic (EOBD) System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an
  2. Determine if fault is present. Reviews Freeze Frame data to determine when the DTC set. Always record this information.

DTC P0461 - Fuel Level Stuck

Step Action Value(s) Yes No
1
Perform an On-Board Diagnostic (EOBD) System Check.
Is the system check complete?
-
Go to Step 2
Go to "On-Board Diagnostic System Check"
2
  1. Install a scan tool to the Data Link Connector (DLC).
  2. Start the engine and operate the vehicle over the specified mileage.
Is any of the Diagnostic trouble Codes (DTCs) P0462, P0463 or P0502 set?
250 km
(155 mile)
Go to Applicable DTC table
Go to Step 3
3
  1. Turn the ignition OFF.
  2. Disconnect the fuel pump connector.
  3. Turn the ignition ON.
  4. Using a voltmeter, measure the fuel level signal voltage at the fuel level sensor connector terminal 1.
Is the voltage within the specified value?
4-5 volts
Go to Step 4
Go to Step 5
4
  1. Disconnect the Engine Control Module (ECM).
  2. Check the fuel level sensor ground circuit for an open between terminal 6 of the fuel sensor connector and terminal K34 of the ECM and repair as needed.
Is the repair complete?
-
Go to Step 10
Go to Step 6
5
Using a voltmeter, measure the voltage at the ECM connector terminal K34 by back-probing the ECM connector.
Is the voltage within the specified value?
4-5 V
Go to Step 8
Go to Step 9
6
  1. Remove the fuel pump from the fuel tank.
  2. Reconnect the fuel pump connector.
  3. Turn the ignition ON.
  4. Monitor the fuel level sensor parameter on the scan tool while moving the fuel sensor float from empty position to full position.
  5. Repeat procedure 4 several times.
Does the fuel level sensor vale on the scan tool increase and then decrease steadily when the float is moved?
-
Go to "Diagnostic Aids"
Go to Step 7
7
  1. Turn the ignition OFF.
  2. Replace the fuel pump assembly.
-
Go to Step 10
-
8
  1. Turn the ignition OFF.
  2. Disconnect the ECM connector.
  3. Check the fuel level signal circuit fir an open or short to ground between terminal K51 and fuel pump harness connector terminal 1 and repair as needed.
Is the repair complete?
-
Go to Step 10
-
9
  1. Turn the ignition OFF.
  2. Replace the ECM.
Is the repair complete?
-
Go to Step 10
-
11
  1. Using the scan tool, clear the Diagnostic Trouble Codes (DTCs).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic ran and passed?
-
Go to Step 11
Go to Step 2
12
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?
-
Go to applicable DTC table
System OK

V4B11F15
Display graphicTranslations of text in graphics


Diagnostic Trouble Code (DTC) P0462

Fuel Level Low Voltage

Circuit Description

The Engine Control Module (ECM) uses the signal from the fuel level sensor to calculate expected vapor pressure within the fuel system. Vapor pressure varies as the fuel level changes. The fuel level signal also used to determine if the fuel level is too high or too low to be able to detect Evaporative Emission (EVAP) system faults. This Diagnostic Trouble Code (DTC) detects a continuous short to low or open in either the signal circuit or the fuel level sensor.

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

Inspect harness connector for backed-out terminal, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
Inspect wiring harness for damage.
A stuck fuel level sensor may cause the DTC set.
If the DTC P0462 cannot be duplicate, the information included on the Failure record data can be useful in determine vehicle conditions when the DTC was first set.
Resistance checks for fuel level sensor:

Test Description

The number(s) below refer to step(s) on the diagnostic table.
  1. The On-Board Diagnostic (EOBD) System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
  2. Determine if fault is present. Review Freeze Frame data to determine when the DTC set. Always record this information.

DTC P0462 - Fuel Level Low Voltage

Step Action Value(s) Yes No
1
Perform an On-Board Diagnostic (EOBD) System Check.
Was the check performed?
-
Go to Step 2
Go to "On-Board Diagnostic System Check"
2
  1. Install a scan tool to the Data Link Connector (DLC).
  2. Start the engine and operate the vehicle within Failure Record condition as noted.
Is Diagnostic trouble Codes (DTCs) P0462 set?
-
Go to Step 3
Go to "Diagnostic Aids"
3
  1. Turn the ignition OFF.
  2. Disconnect the fuel pump connector.
  3. Turn the ignition ON.
  4. Using a voltmeter, measure the fuel level signal voltage at the fuel level sensor connector terminal 1.
Is the voltage within the specified value?
0.4 - 4.5 V
Go to Step 4
Go to Step 6
4
Check for a proper ground connection at the fuel tank and repair as needed.
Is the repair complete?
-
Go to Step 11
Go to Step 5
5
  1. Remove the fuel pump from the fuel tank.
  2. Reconnect the fuel pump connector.
  3. Turn the ignition ON.
  4. Monitor the fuel level sensor parameter on the scan tool while moving the fuel sensor float from empty position to full position.
  5. Repeat procedure 4 several times.
Does the fuel level sensor vale on the scan tool increase and then decrease steadily when the float is moved?
-
Go to "Diagnostic Aids"
Go to Step 8
6
Check for an open or short to ground in the fuel level sensor circuit and repair as needed.
Is the repair necessary?
-
Go to Step 11
Go to Step 9
7
Repair the open or short to ground in the fuel level sensor circuit between the fuel level sensor harness connector and fuel level sensor.
Is the repair complete?
-
Go to Step 11
-
8
  1. Turn the ignition OFF.
  2. Replace the fuel pump assembly.
Is the repair complete?
-
Go to Step 11
-
9
  1. Turn the ignition OFF.
  2. Connect the fuel pump connector.
  3. Disconnect the engine Control Module (ECM) connector.
  4. Turn the ignition ON.
  5. Using a digital voltmeter, measure the voltage in the signal circuit at terminal K51.
Is the voltage within the specified value?
4-5 V
Go to Step 10
Go to Section 9E, Instrumentation/Driver Information
10
  • Turn the ignition OFF.
  • Replace the ECM.
Is the repair complete?
-
Go to Step 11
-
11
  1. Using the scan tool, clear the Diagnostic Trouble Codes (DTCs).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the vehicle within the Conditions for setting this DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic has run and passed?
-
Go to Step 12
Go to Step 2
12
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?
-
Go to applicable DTC table
Go to System OK

V4B11F15
Display graphicTranslations of text in graphics


Diagnostic Trouble Code (DTC) P0463

Fuel Level High Voltage

Circuit Description

The Engine Control Module (ECM) uses the signal from the fuel level sensor to calculate expected vapor pressure within the fuel system. Vapor pressure varies as the fuel level changes. The fuel level signal also used to determine if the fuel level is too high or too low to be able to detect Evaporative Emission (EVAP) system faults. This Diagnostic Trouble Code (DTC) detects a continuous short to low or open in either the signal circuit or the fuel level sensor.

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

Inspect harness connector for backed-out terminal, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
Inspect wiring harness for damage.
A stuck fuel level sensor may cause the DTC set.
If the DTC P0462 cannot be duplicate, the information included on the Failure record data can be useful in determine vehicle conditions when the DTC was first set.
Resistance checks for fuel level sensor:

Test Description

The number(s) below refer to step(s) on the diagnostic table.
  1. The On-Board Diagnostic (EOBD) System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
  2. Determine if fault is present. Review Freeze Frame data to determine when the DTC set. Always record this information.

DTC P0463 - Fuel Level High Voltage

Step Action Value(s) Yes No
1
Perform an On-Board Diagnostic (EOBD) System Check.
Was the check performed?
-
Go to Step 2
Go to "On-Board Diagnostic System Check"
2
  1. Install a scan tool to the Data Link Connector (DLC).
  2. Start the engine and operate the vehicle within Failure Record condition as noted.
Is Diagnostic trouble Codes (DTCs) P0463 set?
-
Go to Step 3
Go to "Diagnostic Aids"
3
  1. Turn the ignition OFF.
  2. Disconnect the fuel pump connector.
  3. Turn the ignition ON.
  4. Using a voltmeter, measure the fuel level signal voltage at the fuel level sensor connector terminal 1.
Is the voltage within the specified value?
0.4 - 4.5 V
Go to Step 4
Go to Step 6
4
Check for a proper ground connection at the fuel tank and repair as needed.
Is the repair necessary?
-
Go to Step 11
Go to Step 5
5
  1. Remove the fuel pump from the fuel tank.
  2. Reconnect the fuel pump connector.
  3. Turn the ignition ON.
  4. Monitor the fuel level sensor parameter on the scan tool while moving the fuel sensor float from empty position to full position.
  5. Repeat procedure 4 several times.
Does the fuel level sensor vale on the scan tool increase and then decrease steadily when the float is moved?
-
Go to "Diagnostic Aids"
Go to Step 8
6
Check for short to voltage in the fuel level sensor circuit and repair as needed.
Is the repair necessary?
-
Go to Step 7
Go to Step 9
7
Repair the short to voltage in the fuel level sensor circuit between the fuel level sensor harness connector and fuel level sensor.
Is the repair necessary?
-
Go to Step 11
-
8
  • Turn the ignition OFF.
  • Replace the fuel pump assembly.
Is the repair complete?
-
Go to Step 11
-
9
  1. Turn the ignition OFF.
  2. Connect the fuel pump connector.
  3. Disconnect the engine Control Module (ECM ) connector.
  4. Turn the ignition ON.
  5. Using a digital voltmeter, measure the voltage in the signal circuit at terminal K51.
Is the voltage within the specified value?
0.4 - 4.5 V
Go to Step 10
Go to Section 9E, Instrumentation/ Driver Information
10
  • Turn the ignition OFF.
  • Replace the ECM.
Is the repair complete?
-
Go to Step 11
-
11
  1. Using the scan tool, clear the Diagnostic Trouble Codes (DTCs).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the vehicle within the Conditions for setting this DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic has run and passed?
-
Go to Step 12
Go to Step 2
12
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?
-
Go to applicable DTC table
Go to System OK


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