Okay, possible issues.
What is the voltage at the coolant sensor engine off, key on?
Cooling System Performance
Engine Coolant Level and Condition
Engine Coolant Temperature (ECT) Sensor
Engine Coolant Temperature (ECT) Sensor Signal Circuit High Resistance
Engine Coolant Temperature (ECT) Sensor Wiring or Connectors
Powertrain Control Module (PCM)
Sensor Ground Circuit High Resistance
- Set Condition:
The ECT sensor voltage should only change at a certain rate. If this rate is too slow or too fast, this fault will set. Two trip fault. Three good trips to clear MIL. ETC light will illuminate on first trip failure.
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Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See: Computers and Control Systems > Initial Inspection and Diagnostic Overview > Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DTC
NOTE: Improper installation of a block heater could cause this DTC to set.
NOTE: Review Freeze Frame data. Extremely cold ambient temperatures may cause this DTC to set.
NOTE: Diagnose and repair any ECT sensor circuit or temperature sensor performance DTCs before continuing with this test.
NOTE: Inspect the cooling system for any conditions that can cause a change in engine warm up time, such as a broken water pump impeller or the addition of an aftermarket auxiliary cooler.
1. Turn the ignition on.
2. With the scan tool, select View DTCs.
Is the status Active for this DTC?
- Go To 2
- Refer to the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See: Computers and Control Systems > Initial Inspection and Diagnostic Overview > Checking for an Intermittent DTC.
2. CHECKING THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION
1. Perform the diagnostic procedure for CHECKING THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION. See: Computers and Control Systems > Component Tests and General Diagnostics > Checking the Engine Coolant Temperature Sensor Operation.
Were any problems found?
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > PCM Verification Test
- Perform the POWERTRAIN VERIFICATION TEST.. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > PCM Verification Test
Thursday, July 11th, 2019 AT 7:33 AM