Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Test
- ACTIVE DTC
- Turn the ignition on.
- With the scan tool, read DTCs. Record DTC and Freeze Frame information.
- 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.
- With the scan tool, read the active DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK THE (K43) O2 SENSOR 2/1 SIGNAL CIRCUIT
- O2 SENSOR
- Measure the voltage on the (K902) O2 Sensor 2/1 Return circuit in the O2 Sensor 2/1 harness connector.
Is the voltage at 2.5 volts?
Yes
- Verify that there is good pin to terminal contact in the O2 Sensor 2/1 and Powertrain Control Module connectors. If OK, replace the O2 Sensor 2/1. Refer to SENSOR, OXYGEN, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 4
- Measure the voltage on the (K902) O2 Sensor 2/1 Return circuit in the O2 Sensor 2/1 harness connector.
- CHECK THE (K902) O2 SENSOR 2/1 RETURN CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition off.
- Disconnect the PCM C2 harness connector.
- Measure the resistance between ground and the (K902) O2 Sensor 2/1 Return circuit in the O2 Sensor 2/1 harness connector.
Is the resistance above 10k Ohms?
Yes
- Go To 8
No
- Repair the (K902) O2 Sensor 2/1 Return circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (K43) O2 SENSOR 2/1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition off.
- Disconnect the PCM C2 harness connector.
- Measure the resistance between ground and the (K43) O2 Sensor 2/1 Signal circuit in the O2 Sensor 2/1 harness connector.
Is the resistance above 10k Ohms?
Yes
- Go To 6
No
- Repair the (K43) O2 Sensor 2/1 Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK FOR THE (K43) O2 SENSOR 2/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 SENSOR 2/1 RETURN CIRCUIT
Courtesy of CHRYSLER GROUP, LLC
- Measure the resistance between the (K43) O2 Sensor 2/1 Signal circuit and the (K902) O2 Sensor 2/1 Return circuit in the O2 Sensor 2/1 harness connector.
Is the resistance above 10k Ohms?
Yes
- Repair the short between the (K902) O2 Sensor 2/1 Return circuit and the (K43) O2 Sensor 2/1 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 7
- Measure the resistance between the (K43) O2 Sensor 2/1 Signal circuit and the (K902) O2 Sensor 2/1 Return circuit in the O2 Sensor 2/1 harness connector.
- CHECK FOR THE (K43) O2 SENSOR 2/1 SIGNAL CIRCUIT SHORTED TO THE O2 SENSOR HEATER GROUND CIRCUIT
Courtesy of CHRYSLER GROUP, LLC
- Measure the resistance between the (K43) O2 Sensor 2/1 Signal circuit and the O2 Sensor Heater Ground circuit in the O2 Sensor harness connector.
Is the resistance above 10k Ohms?
Yes
- Repair the short between the O2 Sensor Heater Ground circuit and the (K43) O2 Sensor 2/1 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 8
- Measure the resistance between the (K43) O2 Sensor 2/1 Signal circuit and the O2 Sensor Heater Ground circuit in the O2 Sensor harness connector.
- POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/1 and the Powertrain Control Module (PCM).
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Oxygen Sensor 2/1 and Powertrain Control Module connectors.
- Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.