Circuit Description
The Engine Coolant Temperature sensor is a thermistor, a sensor whose resistance varies with temperature. The ECT sensor signal is on CKT 410 and sensor ground on CKT 808. As the temperature of the sensor increases, resistance decreases. A high coolant temperature will result in low signal voltage on CKT 410. DTC P0117 sets because the coolant temperature cannot be greater than 147°C (247°F) when the IAT is less than 100°C (212°F) or the vehicle has been driving long enough to cool the engine to less than 147°C (247°F).
Conditions for Running the DTC
| • | DTCs P0112 and P0113 not set. |
| • | IAT temperature of 100°C (212°F) or less. |
| • | DTCs P0122 and P0123 not set. |
| • | Engine running with throttle angle between 5 and 35 degrees for at least 3.5 minutes. |
Conditions for Setting the DTC
The ECT sensor reading is 147°C (247°F) or more.
Action Taken When the DTC Sets
| • | PCM uses the transaxle temperature sensor values in place of the engine coolant temperature sensor for the first 4.25 minutes of engine operation, and a value of 90°C (194°F) afterwards. |
| • | Transaxle shift adapts are maintained at current levels. |
| • | The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails. |
| • | The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail. |
| • | A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail. |
| • | A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test. |
| • | Use a scan tool to clear DTCs. |
| • | Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in Powertrain Control Module Description . |
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
-
With the ECT sensor or wiring shorted, ECT display will read 147°C (247°F) or greater.
-
If ECT display reads -29°C (-20°F) or less with ECT sensor disconnected, wiring is okay but ECT sensor must be shorted.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | |
Is the temperature the same or higher than the value specified? | 147°C (247°F) | Go to Step 3 | Fault not present. | |
Disconnect ECT sensor connector. Is the temperature the same or less than the value specified? | -28°C (18°F) | Go to Step 6 | Go to Step 4 | |
4 |
Is resistance of both less than the value specified? | 10K ohms | Go to Step 8 | Go to Step 5 |
5 | Repair short to ground in th ECT sensor signal circuit or the signal shorted to the ground circuit. Is the repair complete? | -- | Go to Powertrain Control Module Diagnosis for Verify Repair | -- |
6 |
Was terminal contact repaired? | -- | Go to Powertrain Control Module Diagnosis for Verify Repair | Go to Step 7 |
7 | Replace the ECT sensor. Refer to Engine Coolant Temperature Sensor Replacement . Is the replacement complete? | -- | Go to Powertrain Control Module Diagnosis for Verify Repair | -- |
8 |
Was terminal contact repaired? | -- | Go to Powertrain Control Module Diagnosis for Verify Repair | Go to Step 9 |
9 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the replacement complete? | -- | Go to Powertrain Control Module Diagnosis for Verify Repair | -- |
