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
- DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE
- 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.
- Using the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- Start the engine and allow it to reach normal operating temperature.
- (K21) IAT SIGNAL CIRCUIT SHORTED TO GROUND
- Turn the ignition off.
- Disconnect the Intake Air Temperature Sensor harness connector.
- Disconnect the Powertrain Control Module (PCM) C2 harness connector.
- Measure the resistance between ground and the (K21) IAT Signal circuit in the Intake Air Temperature Sensor harness connector.
Is the resistance above 100 Ohms?
Yes
- Go To 3
No
- Repair the (K21) IAT Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- (K21) IAT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
Courtesy of CHRYSLER GROUP, LLC
- Measure the resistance between the (K21) IAT Signal circuit and the (K900) Sensor Ground circuit in the IAT Sensor harness connector.
Is the resistance above 100 Ohms?
Yes
- Go To 4
No
- Repair the (K21) IAT Signal circuit for a short to the (K900) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance between the (K21) IAT Signal circuit and the (K900) Sensor Ground circuit in the IAT Sensor harness connector.
- (K21) IAT SIGNAL CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE
- Measure the resistance of the (K21) IAT Signal circuit between the IAT Sensor harness connector and the PCM C2 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the (K21) IAT Signal circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance of the (K21) IAT Signal circuit between the IAT Sensor harness connector and the PCM C2 harness connector.
- INTAKE AIR TEMPERATURE SENSOR
- Turn the ignition off.
- Connect the Powertrain Control Module (PCM) C2 harness connectors.
- Turn the ignition on.
- Using the scan tool, read the IAT Sensor signal voltage.
Is the voltage above 4.5 Volts with the Intake Air Temperature Sensor harness disconnected?
Yes
- Replace the Intake Air Temperature Sensor in accordance with the Service Information. Refer to SENSOR, AIR TEMPERATURE, INLET, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 6
- POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Intake Air Temperature Sensor 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.
- Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
- Look for the data to change or for the DTC to reset during the wiggle test.
- Perform any Technical Service Bulletins that may apply.
Were 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 (PCM) 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.