INACCURATE FUEL ECONOMY READING/REPAIR PROCEDURE

Models Affected: 1989 GRAND PRIX

Condition:

--------- The Electronic Information Center (Option DK4 for Pontiac) may display an inaccurate fuel economy reading. This reading may be 10% to 15% below the actual fuel economy of the vehicle.

Cause:

----- The inaccurate fuel economy is caused by an incorrect fuel consumption value in the MEMCAL. This condition has been corrected for 1990 production.

Correction:

---------- Replace the MEMCAL with the part number listed below:

Broadcast SCAN P/N Code I.D. Engine Trans. Emissions --- ---- ---- ------ ------ --------- 16143619 ATDY 3791 2.8L Man. Fed. 16143620 ATDZ 3801 2.8L Man. Cal. 16143622 ATFA 3811 2.8L Auto. Cal. 16143623 ATFB 3821 2.8L Auto. Fed. 16143624 ATFC 3831 3.1L Auto. Cal. 16143625 ATFD 3841 3.1L Auto. Fed.

IMPORTANT: These MEMCALS include the driveability updates listed in Service Bulletin 89-6-60, but should only be used for inaccurate fuel economy reading condition.

Parts are currently available from GMSPO.

Use the following procedure:

1. Disconnect the negative battery cable.

2. Install the new MEMCAL in the ECM.

3. Reconnect the negative cable. Place the A/C controls in the "off" position.

4. Firmly apply the parking brake and block the drive wheels. Start the engine, and shift the transaxle to "drive" for automatics or "neutral" for manuals.

5. Allow the engine to run until the engine cooling fan has cycled once, or for a maximum or 10 minutes.

6. Turn the ignition "off" for at least 5 seconds.

7. Start the engine, and shift the transaxle to "drive" for automatics or "neutral" for manuals.

8. Allow the engine to run for at least 5 minutes.

Warranty Information: Use Labor Operation J6379, .7 hours, Trouble Code 70

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.