The Transmission Control Module (TCM) receives the vehicle’s Brake Switch 2 message from a vehicle Electronic Control Unit (ECU) over the Primary Data Link (J1939A). This information is used to determine transmission operation.
The TCM monitors Brake Switch 2 messages. If messages are not received or are invalid, the fault is set Active.
FMI 9 - Abnormal Update Rate: Brake Switch 2 message not received for 10 seconds.
FMI 13 - Out of Calibration: Brake Switch 2 message not available for 10 seconds.
FMI 19 – Received Network Data In Error: Brake Switch 2 messages invalid for 10 seconds.
FMI 9, 13, 19:
Note: Vehicle may have additional fallback modes. Refer to OEM.
FMI 9, 13, 19: Brake Switch 2 messages received and valid for 10 seconds.
FMI 9, 13, 19:
Note: Refer to OEM for troubleshooting a failed system.
Set vehicle parking brake and chock wheels.
Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.
If Fault Code 164 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 164 FMI 9, 19 is Active or Inactive, Go to Step B
If Fault Code 164 FMI 13 is Active, refer to OEM and enable vehicle Brake Switch 2 message (SPN 603). Go to Step V
If Fault Code 164 FMI 13 is Inactive, Go to Step V
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 Pedal Switch 2”.
Select all “- 603” SPN sources.
Note: Not all sources will indicate a value.
Monitor 603 - Brake Pedal Switch 2 value. Record reading in table.
Depress and hold service brake.
Release vehicle parking brake.
Monitor 603 - Brake Pedal Switch 2 value. Record reading in table.
Set vehicle parking brake.
Compare reading(s) in table.
If readings are out of range, refer to OEM guidelines for repair of the vehicle Brake Switch 2 message (SPN 603). Go to Step V
If readings are in range and no fault was found, the intermittent nature of the fault makes it likely that the problem is in the vehicle Brake Switch 2 message (SPN 603). Contact OEM for further diagnostic instructions. Go to Step V
Service Brake State | Parameter | Range | Reading(s) |
---|---|---|---|
Released | 603 - Brake Switch | Released | |
Depressed | 603 - Brake Switch | Depressed |
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 164 sets Active, Go to Step A
If a fault code other than 164 sets Active, troubleshoot per Fault Code Isolation Procedure Index.