U1408

U1408-IMPLAUSIBLE BRAKE SIGNAL RECEIVED

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

Theory of Operation

This message is used by the TCM to switch to Coast-Down strategy just prior to vehicle coming to a halt.

When Monitored:
- Continuously with the key-on.

Set Condition:
- When the message is not received or stays unchanged for 10.5 seconds or more for two consecutive key-cycles.






Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. Testing and Inspection

1. CHECK FOR TIPM CAN BUS DTCS
1. With the scan tool, read TIPM DTCs.

Are there any TIPM CAN BUS DTCs present?

Yes

- Refer to DTC Based Diagnostics and perform the appropriate diagnostic procedure.
- Perform AS68RC TRANSMISSION VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Go To 2

2. CHECK IF ENGINE DTCS ARE PRESENT
1. With the scan tool, read engine DTCs.

Are there any engine DTCs present?

Yes

- Refer to DTC Based Diagnostics and perform the appropriate diagnostic procedure.
- Perform AS68RC TRANSMISSION VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM.
- Perform AS68RC TRANSMISSION VERIFICATION TEST. AS68RC Transmission Verification Test