Column Shift

42LE - Automatic Transmission

DIAGNOSIS AND TESTING - BRAKE/ TRANSMISSION SHIFT INTERLOCK SYSTEM
COLUMN SHIFT MODELS













The following chart describes the normal operation of the Brake Transmission Shift Interlock (BTSI) system. If the "expected response" differs from the vehicle's response, then system repair and/or adjustment is necessary.

Refer to the chart that expected shifter response, depending on ignition key/switch (Fig. 374) and brake pedal positions.

If the floor shifter cannot be moved out of the PARK position, refer to Shifter Locked In Place below. If the shift lever can be shifted out of PARK without the brake pedal depressed, refer to Circuit Test below.



SHIFT LEVER LOCKED IN PLACE
1. Remove the instrument panel cover below the steering column, then remove the steering column shrouds to gain access to the Brake Transmission Shift Interlock (BTSI) solenoid.
2. Disconnect the wire connector from the rear of the BTSI solenoid.
3. Insert the ignition key and turn it to the ON position.
4. With the brakes applied, try shifting the transmission shift lever out of the PARK position.
- If the lever now moves freely in and out of PARK, perform the Circuit Test below.
- If the shift lever still does not move from the PARK position, remove the BTSI solenoid from the shift lever assembly.

If the shift lever now moves freely in and out of the park position, the BTSI solenoid is faulty and must be replaced. If the shift lever still does not move from the park position, the problem is in the shift lever assembly or the ignition interlock cassette.



CIRCUIT TEST
1. Check the system fuse in the junction block (An open or blown fuse would allow the shift lever to be moved in and out of the PARK position without the brake pedal applied).
2. Remove the instrument panel cover below the steering column, then remove the steering column shrouds to gain access to the Brake Transmission Shift Interlock (BTSI) solenoid.
3. Disconnect the wire connector from the rear of the BTSI solenoid.
4. Insert the ignition key and turn it to the ON position.
5. Back-probe the wire connector's terminal number 2 with a test light. The test light should illuminate. If not, there is an open or short in the ignition feed circuit leading to the BTSI solenoid. Repair the open or short.
6. Next, back-probe the wire connector with a test light, placing the test light in series between the two wires. At this point, the test light should illuminate. If not, there is an open in the ground circuit or brake lamp switch. Repair the open or replace brake lamp switch as necessary.
7. Depress the brake pedal. The test light should go out. If it does not, there is a short in the ground circuit or brake lamp switch. Repair the short or replace brake lamp switch as necessary.
8. Reconnect the wire connector to the solenoid.

If the circuit passes the above test and the shift lever can still be moved freely in and out of PARK without the brake pedal depressed, replace the BTSI solenoid.