Don't Give Me Any Static - Explorer Keyless Entry Failure

Getting up from your easy chair, you schlep across the carpet, reach for the doorknob to go outside and…zap! That lightning bolt shooting from your finger is nature's reminder that you, my friend, are a great conductor of static electricity. We all know that static electricity can be a nuisance. It can cause computers to quit, spark explosions, fires and can stick unwanted contaminants to particle sensitive products.

Although static electricity and its eradication is a major concern to many industries, it actually has some beneficial uses. Some automobile manufacturers use static electricity to help them paint their vehicles by giving the paint an electrical charge. The charged paint particles are attracted to the metal body and adhere much better than when using conventional methods.

Factories use static electricity to reduce pollution coming from their smokestacks by giving the smoke an electric charge. When it passes by an electrode of the opposite charge, most of the smoke particles cling to the electrode. This keeps the pollution from going out into the atmosphere.

A photocopy machine uses static electricity to copy print to a page. This is done through the science of xerography. One version gives ink an electrical charge so that it will stick to the paper in the designated areas. Another version of a photocopier uses charges to stick the ink to a drum, which then transfers it to the paper.

Despite some of its beneficial uses, static electricity usually spells problems in the automotive industry. One such incidence involves 1995 to 1997 Ford® Explorer® and 1997 Mercury® Mountaineer® and the havoc static electricity plays on the Remote Keyless Entry system.

The Remote Keyless Entry (RKE) system may be rendered inoperative on some vehicles by a static discharge from the seat through the Remote Anti-theft Personality (RAP), module causing it to fail.

The repair entails installing a metal spring clip on the driver and passenger front seats to ground the upper and lower seat track and replacing the RAP module. Grounding the seats will prevent the buildup of static on the seats, reducing the likelihood of future damage to the RAP module.

Service Procedure

1. Using the power seat controls, move the driver seat full travel forward and adjust the height to the full up position. Tilt the seat frame forward (front part of seat in full down position). Lean the upper seat back toward the front of the vehicle.

2. Position the carbon steel grounding clip on the seat track section on the console side of the seat.
Refer to Figure 1.

3. Using a standard screwdriver, pry against the floor to seat the clip onto the bottom of the track.

4. Spread a generous amount of Silicone Brake Caliper Grease and Dielectric Compound (D7AZ-19A331-A, or equivalent) on the upper seat frame track where the clip indent comes in contact with the seat frame. Apply grease in front of the clip (toward the front of the vehicle).

5. Cycle the seat full travel (back and forward) twice to spread the grease the length of the track.

6. Use an ohmmeter to verify that connection is made between the upper and lower seat track rails. Move the seat track to the full front travel position, then move it back 25-76 mm (1-3"). Place one lead of the ohmmeter on the lower seat rail between the two (2) plastic slides, and the second lead on the seat frame track (Figure 2). Any resistance measurement other than an open ensures proper connection/installation.

NOTE: If the seat is against its forward stop, an incorrect verification of the seat frame grounding will be made.

7. For the passenger side seat, move the seat fully forward and set the height adjustment at its lowest point (this rotates the height adjustment linkage away from the seat track area where the clip is to be installed). Lean the upper seat back toward the front of the vehicle.

8. Repeat above Steps 2 through 6 for the passenger side seat. After completing step 3, tilt the passenger seat frame forward (back part of seat in the full up position).

9. Return both seats to their original position.

10. Replace the RAP module.

11. Reprogram the Remote Keyless Entry Transmitters.

The new code number is printed on the replacement RAP module. It's imperative that you inform the customer that the driver side door keypad entrance code has changed.

In your customer's eyes, this level of high quality repair really sets you apart from ordinary shops. Not only did you diagnose and repair the problem, you had the information to go the extra step and preempt any future component failure. Keep up the good work. Your customers are counting on you.

PART NUMBER PART NAME
F77Z-78600B86-AA Spring Clip (2/Pkg)
F7CZ-15604-EA Remote Entry/Keyless Entry (RAP) Module
D7AZ-19A331-A Silicone Brake Caliper Grease And Dielectric Compound