CAT 3406E (Prefix 1MM or 2WS) Fault Code: 27 PID: SPN: 110 FMI: 3 Coolant Temperature voltage high
The Engine Control Module (ECM) detects the following conditions:
•The signal voltage from the engine coolant temperature sensor is greater than 4.95 VDC for more than eight seconds.
•The ECM has been powered for at least two seconds.
•The engine has been running for more than seven minutes.
Probable Causes:
1) ECM Connection/Harness
2) If code 232-3 or 232-4 (5 Volt Supply voltage codes) are active, troubleshoot those instead
3) Temperature sensor failure
4) Temperature sensor harness
5) ECM Failure
![download Hitachi Construction Machinery MPDr Ver 3.7.0.0 [10.2020] Diagnostic Software](https://www.ecuforcetruck.com/wp-content/uploads/2023/05/MPDR-3.7.00-300x300.png)
