P0117

P0117-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW

For a complete wiring diagram, refer to the Wiring Information.





Theory of Operation

The Coolant Temperature Sensor is a variable resistor that functions as a normal two wire 5-volt sensor. The PCM supplies a 5-volt reference and a ground to the sensors low reference signal circuit.

- When Monitored:
With the ignition on. Battery voltage greater than 10.4 Volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the Engine Coolant Temperature Sensor input voltage is below the minimum acceptable value. One Trip Fault. Three good trips to clear the MIL. If the vehicle is equipped with the stop/start feature, the system will be disabled when this DTC is active.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC

NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.

1. Turn the ignition on.
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. Intermittent Condition Test.

2. ECT SENSOR
1. Turn the ignition off.
2. Disconnect the ECT Sensor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read the ECT Sensor voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus 0.1 volts) 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 ECT Sensor and Powertrain Control Module connectors. If OK, replace the ECT Sensor. Engine Coolant Temperature Sensor - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. CHECK FOR THE (K2) ECT SIGNAL CIRCUIT SHORTED TO THE (K915) SENSOR GROUND CIRCUIT




1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance between the (K915) 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 (K915) Sensor ground circuit and the (K2) ECT Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 4

4. CHECK THE (K2) ECT SIGNAL CIRCUIT FOR A SHORT TO GROUND




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

Is the resistance above 10k Ohms?

Yes

- Go To 5

No

- Repair the short to ground in the (K2) ECT Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. 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 ECT Sensor and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.