Engine Coolant Temperature Measurement System - Multiple Sensor Correlation
The signals of multiple engine coolant temperature sensors do not correlate within the calibrated tolerance. One sensor drifts or installation offset between channels.
Affected components
- Engine coolant temperature sensor 1
- Engine coolant temperature sensor 2
- Ecm
Common causes
- High likelihood: One sensor characteristic drifted
- Medium likelihood: Harness incorrectly swapped between channels
Possible symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.