Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 5: This step tests for excessive resistance in the ECT circuit.
- 6: This step isolates the condition. If the temperature changes, test for a condition in the low reference circuit. If the temperature remains the same, test the signal circuit for a condition.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connect End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check - Engine Controls? | - | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 |
|
- | Go to Diagnostic Trouble Code (DTC) List | Go to Step 3 |
| 3 | Observe the ECT sensor parameter with a scan tool while moving the ECT sensor connector and the engine control module (ECM) connector. Refer to Inducing Intermittent Fault Conditions
in Wiring Systems. Does the scan tool indicate an abrupt change in value? |
- | Go to Step 11 | Go to Step 4 |
| 4 | Observe the ECT sensor parameter with a scan tool while moving the wiring harness between the ECT sensor and the ECM. Refer to Inducing Intermittent Fault Conditions
in Wiring Systems. Does the scan tool indicate an abrupt change in value? |
- | Go to Step 11 | Go to Step 5 |
| 5 |
|
129°C (264°F) | Go to Step 9 | Go to Step 6 |
| 6 |
|
129°C (264°F) | Go to Step 7 | Go to Step 8 |
| 7 | Test the low reference circuit of the ECT sensor for high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 14 | Go to Step 10 |
| 8 | Test the signal circuit of the ECT sensor for high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 14 | Go to Step 10 |
| 9 | Test for shorted terminals and poor connections at the ECT sensor. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 14 | Go to Step 12 |
| 10 | Test for shorted terminals and poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 14 | Go to Step 13 |
| 11 | Repair the connector/terminal or circuits as necessary. Refer to Connector Repairs
orWiring Repairs
in Wiring Systems. Did you complete the repair? |
- | Go to Step 14 | - |
| 12 | Replace the ECT sensor. Refer to Engine Coolant Temperature (ECT) Sensor Replacement . | - | Go to Step 14 | - |
| 13 | Replace the ECM. Refer to Engine Control Module (ECM) Replacement
. Did you complete the replacement? |
- | Go to Step 14 | - |
| 14 |
|
- | Go to Step 2 | Go to Step 15 |
| 15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List | System OK |