Diagnostic Test

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, select View the DTCs.

NOTE: All ECT, Intake Air, and Ambient Air Temperature Sensor codes must be diagnosed and repaired before continuing.

NOTE: In cold weather, this DTC could be set by a high powered block heater and no repair would be required.

NOTE: It may be necessary to test drive the vehicle to get the fault to an Active or Pending state because it takes two failed trips to set.

Is the DTC Active or Pending at this time?

Yes
1. Go to 2).
No
1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
2) TEMPERATURE SENSOR CIRCUIT
With a scan tool, read the ECT, Ambient Air Temp, and Intake Air Temp Sensor temp values.

Start the engine.

Allow the engine to reach normal operating temperature while monitoring the three Sensor temperature values.

Is the temperature for each of the Sensors increasing properly?

Yes
1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
No
1. Go to 3).
3) TEMPERATURE SENSOR

Fig 1: Identifying Ambient Air Temperature Sensor Connector Terminals
Courtesy of CHRYSLER LLC

Fig 2: Checking Engine Coolant Temperature Sensor Signal Circuit & Ground Circuit
Courtesy of CHRYSLER LLC

Fig 3: Checking Intake Air Temperature Sensor Signal Circuit & Ground Circuit
Courtesy of CHRYSLER LLC

Disconnect the suspected sensor.

Ignition on, engine not running.

With the scan tool, read the voltage of the suspected Sensor.

Connect a jumper wire between the Sensor Signal circuit and the Sensor ground circuit.

Did the voltage reading start at 4.8 to 5.0 volts and decrease to 0 volts when the jumper wire was installed?

Yes
1. Replace the Sensor.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 4).
  NOTE: Remove the jumper wire before continuing.
4) EXCESSIVE RESISTANCE IN THE TEMPERATURE SENSOR SIGNAL CIRCUIT

Fig 4: Checking Ambient Air Temperature Sensor Signal Circuit
Courtesy of CHRYSLER LLC

Fig 5: Checking Engine Coolant Temperature Sensor Signal Circuit For Open
Courtesy of CHRYSLER LLC

Fig 6: Checking IAT Signal Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the C2 PCM harness connector.

Disconnect the C2 FCM harness connector.

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 Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the Sensor Signal circuit from the Sensor harness connector to the appropriate terminal of special tool #8815 for the ECT Sensor and IAT Sensor.

Measure the resistance of the (G31) AAT Sensor Signal circuit from the Sensor harness connector to the C2 FCM harness connector.

Is the resistance above 5.0 ohms.

Yes
1. Repair the excessive resistance in the Temperature Sensor Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 5).
5) EXCESSIVE RESISTANCE IN THE SENSOR GROUND CIRCUIT

Fig 7: Checking Ambient Air Temperature Sensor Ground Circuit
Courtesy of CHRYSLER LLC

Fig 8: Checking Engine Coolant Temperature Sensor Ground Circuit For Open
Courtesy of CHRYSLER LLC

Fig 9: Checking Sensor Ground Circuit
Courtesy of CHRYSLER LLC

Measure the resistance of the (K900) Sensor ground circuit from the ECT Sensor and IAT Sensor to the appropriate terminal of special tool #8815.

Measure the resistance of the (G931) Sensor ground circuit from the AAT Sensor harness connector to the C2 FCM harness connector.

Is the resistance above 5.0 ohms.

Yes
1. Repair the excessive resistance in the Sensor ground circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 6).
6) PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes
1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .