P0057

P0057-O2 SENSOR 2/2 HEATER CIRCUIT LOW





For a complete wiring diagram Refer to the Wiring Information.

- When Monitored:
Continuously during O2 heater operation with battery voltage between 10.4 and 15.75 volts.

- Set Condition:
The PCM detects that the O2 sensor heater element input is below the minimum acceptable voltage. One trip fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DTC IS ACTIVE
1. Start the engine and allow it to idle for at least 60 seconds.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

2. With a scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. . Intermittent Condition Test

2. O2 HEATER ELEMENT
1. Turn the ignition off.

NOTE: Allow the O2 Sensor to cool down to room temperature.

2. Disconnect the 2/2 O2 Sensor harness connector.
3. Measure the resistance across the O2 Sensor Heater element, between the O2 Heater Control terminal and the O2 Heater ground terminal in the component connector.

NOTE: O2 Heater Element resistance values should be measured at 21.1° C (70° F). The resistance value will vary with different temperature values.

Is the O2 Sensor Heater Element resistance between 2.0 and 30.0 ohms?

Yes

- Go To 3

No

- Verify that there is good pin to terminal contact in the 2/2 O2 Sensor and Powertrain Control Module connectors. If OK, replace the O2 Sensor.
- Perform the POWERTRAIN VERIFICATION TEST.Powertrain Verification Test

3. (K399) O2 2/2 HEATER CONTROL CIRCUIT SHORTED TO GROUND




1. Disconnect the C3 PCM harness connector.
2. Measure the resistance between ground and the (K399) O2 2/2 Heater Control circuit in the O2 Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair the short to ground in the (K399) O2 2/2 Sensor Heater Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST.Powertrain Verification Test.

No

- Go To 4

4. EXCESSIVE RESISTANCE IN THE (K399) O2 2/2 HEATER CONTROL CIRCUIT





CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.

1. Measure the resistance of the (K399) O2 2/2 Heater Control circuit between the 2/2 Oxygen Sensor harness connector and the appropriate terminal of special tool #8815.

Is the resistance below 0.5 ohms?

Yes

- Go To 5

No

- Repair the excessive resistance in the (K399) O2 2/2 Heater Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/2 and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 2/2 O2 Sensor and Powertrain Control Module connectors.
4. Search for any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST.Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST.Powertrain Verification Test.