Diagnostic Test

WARNING: This page is about a different car, the 2011 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
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.
  
  NOTE:
  Diagnose and repair any system voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Go To 2.
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
ECT SENSOR
1. Turn the ignition off.
2. Disconnect the ECT harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read ECT voltage.
  NOTE:
  The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a Volt) with the connector disconnected.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the Sensor and Powertrain Control Module connectors. Replace the ECT Sensor if no issues were found with the connectors. Refer to SENSOR, Coolant Temperature , Removal .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3.
(K2) ECT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Fig 1: Measuring Resistance Between ECT Sensor Signal Circuit And Ground Circuit In Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Measure the resistance between the (K900) Sensor ground circuit and the (K2) ECT Signal circuit in the ECT Sensor harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the short to between the (K900) Sensor ground circuit and the (K2) ECT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4.
(K2) ECT SIGNAL CIRCUIT SHORTED GROUND

Fig 2: Measuring Resistance Between Ground And ECT Sensor Signal Circuit In Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (K2) ECT Signal circuit in the ECT Sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short to ground in the (K2) ECT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5.
EXCESSIVE RESISTANCE IN THE (K2) ECT SIGNAL CIRCUIT

Fig 3: Checking ECT Signal Circuit For An Open Or Excessive Resistance
Courtesy of CHRYSLER LLC

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 the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis.
1. Measure the resistance of the (K2) ECT Signal circuit between the Engine Coolant Temperature Sensor harness connector and the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position).
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 6.
  No
  - Repair the open or excessive resistance in the (K2) ECT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the ECT Sensor 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 Sensor and Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
  Were there any issues 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 .