The Transmission Control Module (TCM) receives the vehicle’s Service Brake Switch signal message over the Primary Data Link. This information is used to determine transmission operation.
The Transmission Control Module (TCM) monitors the Service Brake Switch signal. If the message is not received or invalid, the fault is set active.
FMI 9 - Abnormal Update Rate: Service Brake Pedal Switch signal not received for 5 seconds.
FMI 13 – Out Of Calibration: Service Brake Switch message not available for 5 seconds.
FMI 14 – Special Instructions: Service Brake Switch signal not received after a launch for 1 second.
FMI 19 – Received Network Data In Error: Service Brake Switch message invalid for 5 seconds.
All FMIs:
Note: Refer to OEM regarding vehicle fallback modes.
FMI 9, 13, 14, 19: Service Brake Switch signal received and valid for 10 seconds.
All FMIs:
Note: Refer to OEM for troubleshooting a failed system.
None
Set vehicle parking brake and chock wheels.
Record the transmission fault codes, FMIs, occurrences, and timestamps from the Service Activity Report created during the Diagnostic Procedure.
If Fault Code 160 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 160 FMI 13 is Active, refer to OEM and enable vehicle Brake Switch SPN 597. Go to Step V
If Fault Code 160 FMI 13 is Inactive, Go to Step V
If Fault Code 160 FMI 9, 14 or 19 is Active or Inactive, Go to Step B
Key on with engine running.
Allow air pressure to build to governor cut off.
Key off.
Key on with engine off.
Connect ServiceRanger.
Go To “Data Monitor”.
Select “Status”.
Select “Brake switch”.
Select all of the “- 597” SPN sources.
Note: Not all sources will indicate a value.
Monitor 597 - Brake switch value. Record reading in table.
Depress and hold service brake.
Monitor 597 - Brake switch value. Record reading in table.
Compare reading(s) in table.
If readings are out of range, refer to OEM guidelines for repair or replacement of the Service Brake Switch signal message. Go to Step V
If readings are in range, no fault was found. The intermittent nature of the fault makes it likely that the problem is in the Service Brake Switch signal message. Contact OEM for further diagnostic instructions. Go to Step V
Service Brake State | Parameter | Range | Reading(s) |
---|---|---|---|
Released | 597 - Brake Switch | Released | |
Depressed | 597 - Brake Switch | Depressed |
Key off.
Reconnect all connectors and verify that 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 the vehicle operates properly, test complete.
If Fault Code 160 sets Active during operation, Go to Step A
If a fault code other than 160 sets Active, troubleshoot per Fault Code Isolation Procedure Index.