NAG1 Shifter - ESM

P0930-BTSI CONTROL CIRCUIT LOW - ESM





For a complete wiring diagram Refer to Diagrams/Electrical Electrical Diagrams


- When Monitored:

Continuously with the ignition on.

- Set Condition:

The DTC will set if the high side driver detects a short to ground for 10 seconds.







Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. NAG1 - Pre-Diagnostic Troubleshooting Procedure


Theory of Operation


The brake switch signal must be active before the shift lever can be moved out of the park position. The Shifter Lever Assembly (SLA) Electronic Shift Module (ESM) receives two brake switch signals. The first signal is a CAN C Bus message sent to the shifter lever assembly. The second signal is a hard wired brake switch signal to the shifter lever assembly. The CAN C Bus message is the primary brake switch signal and the hard wired signal serves as the backup brake switch signal.



Diagnostic Test


1. ENGINE DTCs PRESENT

With the scan tool, read Engine DTCs.

Are there any Engine brake DTCs present?

Yes


- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test

No

- Go To 2



2. ABS MODULE DTCs PRESENT

With the scan tool, read ABS Module DTCs.

Are there any ABS DTCs present?

Yes

- Refer to Brakes and Traction Control/Testing and Inspection and perform the appropriate diagnostic procedure.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test

No

- Go To 3



3. (B29) BRAKE SWITCH SIGNAL SHORT TO GROUND





Turn the ignition off to the lock position.

Disconnect the Shifter Lever Assembly harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between ground and the (B29) Brake Switch Signal circuit.

Is the resistance below 5.0 ohms?

Yes

- Repair the (B29) Brake Switch Signal for a short to ground.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test

No

- Go To 4



4. SHIFTER LEVER ASSEMBLY

Using the schematics as a guide, inspect the wiring and connectors. Repair as necessary. Pay particular attention to all power and ground circuits.

If there are no possible causes remaining, view repair.

Repair

- Replace the Shifter Lever Assembly.

- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test