Fault Code 159: Service Brake Circuit 2
J1939: SA 3 SPN 1088 FMI 9, 13, 19
Overview
The Transmission Control Module (TCM) receives the vehicle’s Service Brake Circuit 2 message over the Primary Data Link. This information is used to determine transmission operation.
Detection
The TCM monitors the Service Brake Circuit 2 message. If a failure is detected the fault is set Active.
Conditions to Set Fault Code Active
FMI 9 - Abnormal Update Rate: Service Brake Circuit 2 message not received for 5 seconds.
FMI 13 - Out of Calibration: Service Brake Circuit 2 message not available for 10 seconds.
FMI 19: Service Brake Circuit 2 message invalid for 10 seconds.
Fallback
FMI 9, 13, 19:
- Amber warning lamp on
- No degraded modes
Conditions to Set Fault Code Inactive
FMI 9, 13, 19: Service Brake Circuit 2 message.
Possible Causes
FMI 9, 13, 19:
- Vehicle Components
- Module(s)
- Service Brake Circuit 2
- Primary Data Link
Additional Tools
- None
Fault Code 159 Troubleshooting
Record the transmission fault codes, FMIs, occurrences, and timestamps from the Service Activity Report created during the Diagnostic Procedure.
If Fault Code 159 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 159 FMI 13 is Active, refer to OEM and enable vehicle Service Brake Circuit 2 SPN 1088. Go to Step V
If Fault Code 159 FMI 13 is Inactive, Go to Step V
If Fault Code 159 FMI 9 or 19 is Active or Inactive, refer to OEM guidelines regarding Service Brake Circuit 2 repair or replacement. Go to Step V
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 159 sets Active during operation, Go to Step A
If a fault code other than 159 sets Active, troubleshoot per Fault Code Isolation Procedure Index.