P0115-ENGINE COOLANT TEMP SENSOR SIGNAL VOLTAGE TOO LOW

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on.
Set Condition:
The Engine Coolant Temperature Sensor signal is below 0.12 volt.

Possible Causes

ECT SENSOR

ECT SENSOR SIGNAL CIRCUIT SHORTED TO GROUND

ECT SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER

ENGINE CONTROL MODULE

Diagnostic Test

1.CHECK FOR ACTIVE DTC

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

Is the ECT Sensor voltage below 0.25 volt?

Yes

Go To2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2.ECT SENSOR

Is the voltage above 4.0 volts?

Yes

Replace the ECT Sensor in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Go To3

3.ECT SENSOR SIGNAL CIRCUIT SHORTED TO GROUND

Is the resistance above 1000 ohms?

Yes

Go To4

Repair the ECT Sensor Signal circuit for a short to ground.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

4.ECT SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER

Is the resistance above 1000 ohms?

Yes

Go To5

Repair the ECT Sensor Signal and Ground circuits for a short together.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

5.ENGINE CONTROL MODULE

If there are no possible causes remaining, view repair.

Repair

Replace and program the Engine Control Module in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).