1997 - 1999 Corvette: Service Bulletin: No Start Condition, Non-Functional PCM After Reprogramming

Subject: NO START CONDITION, NON-FUNCTIONAL PCM AFTER REPROGRAMMING (REPLACE/REPROGRAM PCM)
Source: Chevrolet Service Bulletin
Number: 87-65-10
Models: 1997-99 CHEVROLET CORVETTE WITH 5.7L ENGINE (VIN G - RPO LS1)

Condition:

SOME 1997-99 CHEVROLET CORVETTES MAY EXPERIENCE A NON-FUNCTIONAL PCM AFTER REPROGRAMMING THE PCM. THIS MAY RESULT IN A NO-START CONDITION.

Cause:

WHEN REPROGRAMMING THE PCM, THE ON-BOARD CONTROL MODULES MAY ATTEMPT TO COMMUNICATE WITH THE PCM ACROSS THE CLASS II DATA LINK. WHEN THIS HAPPENS, THE REPROGRAMMING PROCEDURE IS INTERRUPTED AND WILL RESULT IN A NON-FUNCTIONAL PCM. IF THIS HAPPENS, A NEW PCM MUST BE INSTALLED AND CALIBRATION DOWNLOADED.

Correction:

WHEN REPROGRAMMING ANY 1997, 1998, OR 1999 CHEVROLET CORVETTE, CHECK AND RECORD ALL STORED TROUBLE CODES. WHEN REPROGRAMMING THE PCM, THE SERVICE METHOD LISTED MUST BE USED TO ENSURE THAT NO OTHER MODULES IN THE VEHICLE ATTEMPT TO COMMUNICATE WITH THE PCM DURING THE REPROGRAMMING PROCEDURE.

SERVICE PROCEDURE:

1. CHECK AND RECORD ALL STORED TROUBLE CODES.

2. INSTALL STAR CONNECTOR CABLE #1 FROM KENT-MOORE TOOL J-42236-A (DATA BUS DIAGNOSTIC SWITCH BOX) TO THE 12 PIN SPLICE PACK/ STAR CONNECTOR WITH EIGHT (8), OR NINE (9) INCOMING WIRES (FIGURE 1, NUMBER 2). INSTALL STAR CONNECTOR CABLE #2 FROM KENT-MOORE TOOL J-42236-A TO THE 12 PIN SPLICE PACK/STAR CONNECTOR WITH FOUR (4) INCOMING WIRES (FIGURE 1, NUMBER 1). THESE SPLICE PACKS ARE LOCATED TO THE LEFT OF THE BCM (BODY CONTROL MODULE). THE SPLICE PACKS/STAR CONNECTORS ARE STAND ALONE AND DO NOT PLUG INTO THE BCM. THE BCM IS LOCATED BEHIND THE PASSENGER FLOOR ACCESS PANEL.

TO INSTALL KENT-MOORE TOOL J-42236-A, BOTH SPLICE PACK/STAR CONNECTOR SHORTING BARS NEED TO BE REMOVED FROM THE SPLICE PACK/STAR CONNECTOR (FIGURE 2, NUMBER 2). THIS IS DONE BY SQUEEZING BOTH ENDS OF THE SHORTING BAR AND PULLING IT AWAY FROM THE SPLICE PACK (FIGURE 2, NUMBER 1).

THE SPLICE PACKS/STAR CONNECTORS MAY HAVE TO BE REMOVED FROM THEIR MOUNTING PINS TO INSTALL KENT-MOORE TOOL J-42236-A. THE SPLICE PACKS/STAR CONNECTORS MUST BE VISUALLY CHECKED TO ENSURE THE PROPER CABLE FROM KENT-MOORE TOOL J-42236-A IS INSTALLED ON THE CORRECT SPLICE PACK/STAR CONNECTOR.

3. ENSURE TOGGLE SWITCH ON KENT-MOORE TOOL J-42236-A IS IN THE STAR CONNECTOR NUMBER 1 POSITION.

4. TURN THE SELECTOR BUTTON ON KENT-MOORE TOOL J-42236-A TO THE "B" MODE.

5. REPROGRAM THE PCM BY FOLLOWING NORMAL PCM REPROGRAMMING PROCEDURES.

6. DISCONNECT TOOL J-42236-A AND REINSTALL BOTH SHORTING BARS BACK ON TO THE SPLICE PACKS.

7. TO ENSURE THE VEHICLE IS NOT RETURNED TO THE OWNER WITH STORED TROUBLE CODES, CHECK ALL VEHICLE MODULES FOR TROUBLE CODES. REFER TO THE SERVICE MANUAL TO CORRECT TROUBLE CODES THAT MAY HAVE BEEN RECORDED PRIOR TO REPROGRAMMING AND ARE STILL PRESENT. ANY TROUBLE CODES THAT MAY APPEAR AFTER THE REPROGRAMMING PROCEDURE MUST ALSO BE DIAGNOSED USING THE SERVICE MANUAL.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these 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 your GM dealer for information on whether your vehicle may benefit from the information.