P0037
P0037-O2 SENSOR 1/2 HEATER CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information.
- When Monitored:
With the engine running and battery voltage greater than 10.4 volts.
- Set Condition:
The Powertrain Control Module (PCM) detects that the Oxygen Sensor 1/2 Heater Control circuit is shorted low.
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 reach normal operating temperature.
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 the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor 1/2 harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to 12 volts, check the Ground circuit in the Oxygen Sensor 1/2 harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 3
No
- Repair the Ground circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
3. (K299) O2 1/2 HEATER CONTROL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) C2 harness connector.
3. Measure the resistance between ground and the (K299) O2 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
Is the resistance below 100 Ohms?
Yes
- Repair the (K299) O2 1/2 Heater Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 4
4. (K299) O2 1/2 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (K299) O2 1/2 Heater Control circuit between the Oxygen Sensor 1/2 harness connector and the Powertrain Control Module (PCM) C2 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the (K299) O2 1/2 Heater Control circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
5. OXYGEN SENSOR 1/2
1. Connect the Powertrain Control Module (PCM) C2 harness connector.
2. Turn the ignition on.
3. With the scan tool, actuate the Oxygen Sensor 1/2 control to the maximum allowable %.
4. Using a 12-volt test light connected to ground, check the (K299) O2 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
NOTE: The test light should flash dimly.
5. With the scan tool, actuate the Oxygen Sensor 1/2 control to the OFF (0%) position.
6. Using a 12-volt test light connected to ground, check the (K299) O2 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
NOTE: The test light should not be illuminated.
Does the test light flash dimly with the actuator ON (25%) and not illuminated with the actuator OFF (0%)?
Yes
- Replace the Oxygen Sensor 1/2. Oxygen Sensor - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 6
6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/2 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.
4. Perform any Technical Service Bulletins (TSBs) that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.