P0928

P0928-BTSI CONTROL CIRCUIT







Theory of Operation

The Brake Transmission Safety Interlock (BTSI) is a safety feature that prohibits movement of the shift lever out of park unless certain conditions are met. The Cluster controls the BTSI solenoid. The Cluster will engage the BTSI solenoid when the module detects the depression of the brake pedal thus allowing the transmission shift lever to move from the park position to any other position. Failure of the control circuit may inhibit the movement of the shift lever and cause this DTC to set.

- When Monitored:
When the ignition is in accessory, run or start position.

- Set Condition:
This Diagnostic trouble Code (DTC) will set if the Cluster detects a problem with the BTSI solenoid control circuit. The DTC will remain active until the Cluster no longer detects a failure of the BTSI control circuit.





1. DETERMINE IF THE DTC IS ACTIVE OR STORED
1. With the scan tool, read Cluster DTCs.

Is the DTC active?

Yes

- Go To 2

No

- Test complete. The conditions that originally set this DTC are no longer present.

2. CHECK THE (K321) BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID UNLOCK CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Disconnect the Cluster C4 harness connector.
3. Disconnect the Shift Lever Assembly C1 harness connector.
4. Measure the resistance between ground and the (K321) Brake Transmission Shift Interlock Solenoid Unlock circuit.

Is the resistance below 10k Ohms?

Yes

- Repair the (K321) Brake Transmission Shift Interlock Solenoid Unlock circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. CHECK THE (K321) BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID UNLOCK CIRCUIT FOR A SHORT TO VOLTAGE




1. Turn the ignition on.
2. Measure the voltage of the (K321) Brake Transmission Shift Interlock Solenoid Unlock circuit.

Is the voltage above 0.5 of a volt?

Yes

- Repair the (K321) Brake Transmission Shift Interlock Solenoid Unlock circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. CHECK THE (K321) BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID UNLOCK CIRCUIT FOR AN OPEN




1. Reconnect the Cluster C4 harness connector.
2. Turn the ignition on.

NOTE: It may be necessary to erase DTCs to actuate the BTSI solenoid.

3. With the scan tool, actuate the BTSI solenoid.
4. Using a 12-volt test light connected to ground, check the (K321) Brake Transmission Shift Interlock Solenoid Unlock circuit in the Shift Lever Assembly C1 harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 5

No

- Repair the (K321) Brake Transmission Shift Interlock Solenoid Unlock circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. CHECK THE SHIFT LEVER ASSEMBLY BTSI SOLENOID
1. Turn the ignition off.
2. Replace the Shift Lever Assembly.
3. Reconnect all previously disconnected connectors.
4. Use the scan tool and erase Cluster DTCs.
5. Turn the ignition off, wait a minimum of 1five seconds, then turn the ignition on.
6. Wait a minimum of one minute, then read Cluster DTCs.

Does the DTC P0928-BTSI CONTROL CIRCUIT reset?

Yes

- Replace the Cluster.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair is complete.
- Perform the BODY VERIFICATION TEST. Body Verification Test.