P0117-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW
P0117-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW
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For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Engine Coolant Temperature Sensor is located on the left side of the engine block under the Intake Manifold. The Engine Coolant Temperature Sensor operates as a typical two wire sensor. It receives a 5-Volt signal on the (K2) ECT Sensor Signal circuit and shares the (K200) Sensor Ground circuit with the Oil Temperature Sensor. When this fault code is active the EGR system will be disabled.
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When Monitored:
With the ignition on.
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Set Condition:
The (K2) Engine Coolant Temperature Sensor Signal circuit voltage is below 0.1 Volt for 0.5 second.
Possible Causes |
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| (K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND |
| (K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K200) SENSOR GROUND CIRCUIT |
| ENGINE COOLANT TEMPERATURE SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Ignition on, engine not running. |
| 2. | With the scan tool, Clear DTCs in the PCM. |
| 3. | Monitor the scan tool for at least two minutes. |
| 4. | Cycle the ignition key off and on several times, leaving the ignition on for at least 10 seconds at a time. |
| 5. | With the scan tool, select View DTCs. |
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. ENGINE COOLANT TEMPERATURE SENSOR
| 1. | Disconnect the Engine Coolant Temperature Sensor harness connector. |
| 2. | With the scan tool, select View DTCs. |
| NOTE: | The scan tool should display a P0118-Engine Coolant Temperature Sensor High DTC as active with the connector disconnected. |
Does the scan tool display the DTC as described above?
Yes
- Replace the Engine Coolant Temperature Sensor in accordance with the Service Information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 3
3. CHECK THE (K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
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| 1. | Turn the ignition off. |
| 2. | Disconnect the PCM C1 harness connector. |
| 3. | Measure the resistance between ground and the (K2) Engine Coolant Temperature Sensor Signal circuit at the Engine Coolant Temperature Sensor harness connector. |
Is the resistance above 10k Ohms?
Yes
- Go To 4
No
- Repair the (K2) Engine Coolant Temperature Sensor Signal circuit for a short to ground.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
4. CHECK FOR THE (K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO (K200) SENSOR GROUND CIRCUIT
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| 1. | Measure the resistance between the (K2) Engine Coolant Temperature Sensor Signal circuit and the (K200) Sensor Ground circuit at the Engine Coolant Temperature Sensor harness connector. |
Is the resistance above 10k Ohms?
Yes
- Go To 5
No
- Repair the (K2) Engine Coolant Temperature Sensor Signal circuit for a short to the (K200) Sensor Ground circuit.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
| 1. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Coolant Temperature 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. |
| 4. | Perform any Technical Service Bulletins that may apply. |
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace the Powertrain Control Module in accordance with the Service Information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).