Bonneville V6-3800 3.8L (1991)
Shift Interlock Solenoid: Customer Interest
A/T - 4T60 High Shift Effort Out of Park
Bulletin Number:
91-7-22
Reference Number:
077150
Publish Date:
12/90
Subject:
HIGH SHIFT EFFORT OUT OF PARK/LOCKED IN PARK(INFORM CUSTOMER OF BRAKE-TRANS SHIFT PROC./ADJUST
BTSI)
Models
Affected:
1991 BONNEVILLE
BULLETIN COVERS:
A vehicle equipped with a HYDRA-MATIC 4T60 may exhibit high shift effort when the customer is trying to shift the transaxle out of the Park range.
This could be caused by the customer not following the proper shifting procedure for the brake-transaxle shift interlock (BTSI) system. The BTSI system
is designed to prevent the vehicle from being shifted out of Park unless the brake pedal is fully depressed BEFORE the shift lever is moved. When the
brake pedal is depressed, the BTSI solenoid is de-energized, allowing the shift lever to be moved out of the Park range (provided that the shift lever is all
the way in Park).
Customers may comment that their vehicle requires a high shift effort to shift out of Park. This is usually caused by the customer FIRST moving the shift
lever, then depressing the brake pedal or trying to do both simultaneously. This will cause the interlock system to function as intended and hold the shift
lever in the Park range until the shift lever is moved back fully into the Park range. Floor shift console models must have the button on the shift lever
fully released before it is depressed again to disengage the interlock.
Proper shifting procedure to be communicated to the customer:
Ensure the shift lever is fully in the Park range before starting the engine. Your vehicle has a brake-transaxle shift interlock. You have to fully apply your
regular brakes before you can shift from Park when the ignition key is in the "Run" or "On" position. If you cannot shift out of Park, ease pressure on the
shift lever (push the shift lever all the way into Park and also release the shift lever button on floor shift console models) as you maintain brake
application. Then move the shift lever into the gear you wish (provided floor shift console models have the shift lever button depressed again).
SERVICE PROCEDURE:
Test the BTSI system and if "OK", inform the customer of the proper shifting procedure. If adjustment is needed to allow the BTSI solenoid to interlock,
follow the procedure listed in "ON-VEHICLE ADJUSTMENT PROCEDURE FOR COLUMN BTSI SYSTEM" or the Service Manual. Only the
column shift lever system is adjustable. The floor shift console models use a system that does not have an adjustment. The column mounted shift lever
models have the BTSI solenoid location on the steering column, while floor shift console models have the solenoid located in the console.
SERVICE MANUAL REFERENCE:
Refer to the Steering Column Unit Repair section 3F4 for column shift models and Automatic Transaxle On-Vehicle Service section 7A for floor shifter
models in the appropriate 1991 Service Manual.
LABOR TIME INFORMATION:
Use the following labor time guide information when replacing or adjusting the BTSI solenoid:
ON-VEHICLE ADJUSTMENT PROCEDURE FOR COLUMN BTSI SYSTEM:
With the steering column in the vehicle, use the following procedure to adjust the BTSI system interlock. Use Labor Operation N3475 to adjust the BTSI
