Diagnostic Test

Fig 1: SCAN TOOL (STARSCAN)

Courtesy of DAIMLERCHRYSLER CORP.

Ignition on, engine not running.

With a scan tool, read the ECT voltage.

Is the voltage below 0.078 of a volt? 

Yes 

1. Go To step  2).

No 

1. Refer to INTERMITTENT CONDITION .
2. Perform NGC POWERTRAIN VERIFICATION TEST VER - 5 .

Turn the ignition off.

Disconnect the ECT harness connector.

Ignition on, engine not running.

With a scan tool, read ECT voltage.

Is the voltage above 1.0 volt? 

Yes 

1. Replace the ECT Sensor.
2. Perform NGC POWERTRAIN VERIFICATION TEST VER - 5 .

No 

1. Go To step  3).

Fig 2: Checking Engine Coolant Temperature Sensor Signal Circuit & Ground Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the PCM harness connectors.

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 

1. Repair the short to between the (K900) Sensor ground circuit and the (K2) ECT Signal circuit.
2. Perform NGC POWERTRAIN VERIFICATION TEST VER - 5 .

No 

1. Go To step  4).

Fig 3: Checking Engine Coolant Temperature Sensor Signal Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (K2) ECT Signal circuit in the ECT Sensor harness connector.

Is the resistance below 100 ohms? 

Yes 

1. Repair the short to ground in the (K2) ECT Signal circuit.
2. Perform NGC POWERTRAIN VERIFICATION TEST VER - 5 .

No 

1. Go To step  5).

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 NGC POWERTRAIN VERIFICATION TEST VER - 5 .

No 

1. Replace and program the Powertrain Control Module. Refer to MODULE-POWERTRAIN CONTROL .
2. Perform NGC POWERTRAIN VERIFICATION TEST VER - 5 .