NAG1 Shifter - ESM (Column Shift)

P0930-BTSI CONTROL CIRCUIT LOW - ESM (COLUMN SHIFT)





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


Theory of Operation


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


- 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



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 symptom(s).
- 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 ESM harness connector.

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

- Using the schematics as a guide, check the Electronic Shift Module (ESM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the ESM (Steering Column).
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test