U1479

U1479-IMPLAUSIBLE DATA RECEIVED FROM SHIFTER - MECHANICAL FAILURE

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The purpose of the diagnostic is to detect a breakage of the mechanical connection between the shift lever and the sensor module mounted to the lever. The shift lever is moved about a pivot point located in the middle of the lever and is held in the home position by two opposing springs. The sensor module consists of two redundant sensors and is mounted to the lower end of the shift lever by a connection pin. The driver controls the shift lever by pushing or pulling the upper end of the lever and the position is read by the sensor module. If the connection pin between the shift lever and the sensor module breaks then the sensor module is pulled to a failure position by a separate spring mounted to the sensor module.

- When Monitored:
When the ignition switch is turned to the run position.

- Set Condition:
The failure is detected if one or both of the two shifter position sensors indicate the sensor module failure position is reached.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 8HP45 Pre-Diagnostic Troubleshooting Procedure

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

Are any TCM CAN BUS DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure. Perform the diagnostic procedure for DTC U0001-CAN C BUS first if the fault is present.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Go To 2

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

Are any ESM DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.
- Using the schematics as a guide, check the Electronic Shift Module terminals for damage or terminal push out. If no problems are found, replace the ESM. Transmission Shifter - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Using the schematics as a guide, check the Transmission Control Module Assembly (TCMA) terminals for corrosion, damage or terminal push out. If no problems are found, replace and program the TCMA. Valve Body - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.