4WAL EHCU DIAG. AND EXCHANGE PROGRAM (SERVICE INFORMATION)

SUBJECT: 4WAL EHCU DIAGNOSTIC AND EXCHANGE PROGRAM

MODELS: 1991 SYCLONE

This bulletin covers preliminary diagnosis and an exchange procedure for the Four Wheel Antilock (4WAL) Electro Hydraulic Control Unit (EHCU).

In order to give needed product feedback, ANY EHCU needing warranty repair will be exchanged for a replacement unit. This program is being applied to the Syclone to aid in future product improvements.

Important! Customer pay units requiring repair can continue to be serviced using parts available through GMSPO.

SERVICE INFORMATION

Preliminary Diagnosis Procedure: - Verify codes set indicate an EHCU failure requiring replacement. - Ensure all wiring connections are making good contact and are properly seated.

EXCHANGE PROCEDURE:

1. Reference the attachment and have information available before calling. Be sure to note the exact customer concerns. It is necessary to record this information as it will be needed to fill out the form on the EHCU returned. (Blank forms will be shipped with exchange unit.)

2. Call Technical Assistance (GMC 1-800-624-2022). After it has been determined that an EHCU replacement is required, Technical Assistance will arrange with Kelsey-Hayes* to ship an exchange unit within one working day (24 hours).

3. Dealerships will be provided with an authorization number by Kelsey-Hayes. Write the authorization number on the return form.

4. Once an exchange unit is received, the replaced unit is to be returned to Kelsey-Hayes within 8-10 days to avoid a chargeback/ debit. A return shipping label will be sent with the exchange unit.

5. The exchange unit will have a plastic bag with it. This bag will contain:

* Return shipping label * Reporting form * Return shipping carrier information

NOTE: Technician should thoroughly bleed the brake system following EHCU Replacement (reference GMC Truck Service Bulletin 90-5E-48, Corporate number 065001R.)

PREPARATION FOR SHIPPING

1. Remove all plastic shipping plugs and covers from the replacement unit, and install them on the replaced unit.

2. Write the authorization number on the return form.

Place the report form and a copy of the repair order in the enclosed plastic bag. Attach the bag to the replaced unit with enclosed wire.

3. Repack the replaced unit into the original shipping container.

4. Place the shipping label on the original shipping container.

Important

All return shipping will be paid by Kelsey-Hayes.

WARRANTY INFORMATION

For repairs performed under warranty, claims may be submitted for R&R labor and Delco Supreme Fill Brake Fluid or its DOT 3 equivalent, if required. Replacement EHCUs will be shipped to the dealer on a no-charge basis.

For vehicles repaired under warranty, use:

Labor Labor 8Parts Operation Description Time Allowance --------- ------------- ------- ---------- H2505 EHCU Remove 1.3 hrs. $154.62 and Replace

*The amount identified in the "Parts Allowance" column above represents 30% of dealer net for parts that were furnished by Kelsey-Hayes. This amount is to be placed in the Net item Amount column of the claim and type Code "M."

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.