For 1990-2009 cars

# Electrical Accessories Intermittently Inoperative, MIL On and DTCs Set in PCM Memory, and/or Key Binds in RUN Position

Subject: | Electrical Accessories Intermittently Inoperative, MIL On and DTCs Set in PCM Memory, and/or Key Binds in RUN Position -- Modify Ignition Lock Cylinder Tumbler -- Due to changes under MODELS AFFECTED to distinguish 1997 vehicles with first design locks, this bulletin supersedes 96-T-50, which should be discarded.

Models: | 1995-1996 Saturns, and 1997 Saturns equipped with first design locks

### Condition:

1. Electrical accessories may intermittently lose power after starting the vehicle or while the vehicle is in operation. Some of the accessories that may lose power are: radio, power windows, rear defog, DRL, cruise control, HVAC blower and/or A/C compressor.

Turning the ignition key OFF and restarting the vehicle or rocking the ignition key in the RUN position may restore operation of these accessories.

2. The MIL --Service Engine Soon telltale-- on 1995 vehicles, or the Service (Wrench) telltale on 1996 or 1997 vehicles may be ON during the loss of power. Possible trouble codes (DTC)s are listed below.

Model Year | DTCs | Possible Cause
--- | --- | ---
1995 | 26, 27 | Voltage drop on quad driver circuits
1996 and First Design 1997 | P1640, P1641 | Low cruise module voltage
| P1650, P1651 | Low A/C relay voltage
| P0571, P0572 | Low cruise brake switch voltage
| P1602 | Loss of ABS module data

3. The ignition key may bind in the ignition lock cylinder at the RUN position. The condition may be compounded by the added weight on the key chain of additional keys and other items.

### Cause:

The tumbler in the 7th position, tumbler nearest the locking pin end, of the ignition lock cylinder may be binding as the ignition key is returned from Start to Run. This binding may result in poor or no electrical switch contact for ignition circuits 4 and/or 300.

### Correction:

Modify the corner of the tumbler in the 7th position, the position nearest the locking pin end, of the ignition lock cylinder according to the procedure in this bulletin.

Important: To help identify if a 1997 vehicle is equipped with a first or second design lock system, check the key. The new second design lock system has a different shaped key than the key used in the first design lock system, refer to the above illustrations.

### Procedure:

1. Remove the ignition lock cylinder following the procedure in the appropriate year Body/Repair Service Manual.
2. Remove the 7th position tumbler, tumbler nearest the locking pin, (1) in the illustration, from the lock cylinder.
3. Using a file, bevel the corner of the tumbler, opposite the spring tab (1) as shown in the illustration. There are 4 tumblers, numbered 1-4 that can be used in any of the 7 positions, the #3 tumbler shown in the illustration is typical.

File the corner to the first notch (2) at approximately a 30 degree angle. Smooth any burrs left by the filing operation and clean as necessary.

Notice: Care should be taken not to file any other corner of the tumbler. If any of the other corners are rounded during this operation, the security of the ignition lock could be reduced. If any other corners are rounded, replace the tumbler and repeat step 3 of this bulletin.

4. Install the modified tumbler and spring in the lock cylinder. Refer to the appropriate year Body/Repair Service Manual.
5. Oil the lock cylinder assembly with light oil or graphite lubricant and install it into the ignition switch housing. Refer to the appropriate year Body/Repair Service Manual.

Notice: Never use silicon spray type lubricant. Silicon spray type lubricants wash away any existing oil from the lock cylinder and then evaporate. This leaves less lubricant in the lock cylinder, which may cause the lock cylinder to bind.

Claim Information: | Case Type | Description | Labor Operation Code | Time
--- | --- | --- | --- | ---
-- | VW | Modify Ignition Lock Cylinder Tumbler | T9726 | 0.40 hrs