Fault Code 345 Engine (Over) Speed
J1939: SA 3 SPN 5052 FMI 0
Overview
The Transmission Control Module (TCM)) receives the vehicle’s Engine Speed messages from a vehicle Electronic Control Unit (ECU) over the Primary Data Link (J1939A). The TCM uses the Engine Speed as the primary engine speed message during normal transmission operation. The Primary Data Link is connected to the TCM at the 20-Way TCM Vehicle Harness Connector.
Detection
The TCM monitors Engine Speed messages. If messages are not received or are invalid, the TCM sets the fault code Active.
Conditions to Set Fault Code Active
FMI 0 – Data Erratic: Engine speed message indicates engine rpm greater than 2600 rpm with the clutch open.
Fallback
FMI 0:
- No degraded modes
Conditions to Set Fault Code Inactive
FMI 0: Engine speed message indicates engine speed less than 2500 rpm or clutch closed for 10 seconds.
Possible Causes
FMI 0:
- Descending an overly steep grade
- Excessive vehicle weight
Additional Tools
- None
Fault Code 345 Troubleshooting
Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.
If Fault Code 345 FMI 0 is Active or Inactive, contact Eaton Cummins Automated Transmission Technologies at +1 800-826-4357 for further diagnostic instructions. Go to Step V
Key off.
Reconnect all connectors and verify all components are properly installed.
Key on with engine off.
Connect ServiceRanger.
Go To “Fault Codes”.
Select “Clear All Faults”.
Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.
Check for fault codes using ServiceRanger.
If no fault codes set and vehicle operates properly, test complete.
If Fault Code 345 sets Active, contact Eaton Cummins Automated Transmission Technologies at +1 800-826-4357 for further diagnostic instructions.
If a fault code other than 345 sets Active, go to Fault Code Isolation Procedure Index.