PROM - Stalls After Initial Start or During Warm Up

NO.:
92-T-33

DATE:
June, 1992

GROUP:
Engine

CORP. NO.:
286502



SUBJECT:
Engine Stalls After Initial Start, or During Warm-Up and May Restart with Increased Idle, SOHC (LKO) Engines (Install New PCM Calibration)

MODELS
AFFECTED:
All 1992 Saturns with SOHC (LKO) engines

CONDITION:
Some customers of 1992 Saturns, equipped with SOHC (LKO) engines may comment that the engine stalls after the vehicle is initially started, or stalls when first shifted into gear or during engine warm-up. Customers may also comment of increased-idle conditions after a stall on initial start while vehicle is out of gear.

CAUSE:
Due to engine sensitivity to variations in cool ambient temperatures along with the new 1992 Federal regulations that address Spring and Summer fuel grade volatility, initial start-up and warm-up driveability has been impacted, especially on new engines.

CORRECTIVE ACTION:
Verify that the start/stall condition occurs during initial start or engine warm-up, then proceed with the Steps listed under "Procedures".

IMPORTANT:
On all vehicles built before January 1, 1992, refer to Technical Information Bulletin 91-T-35A (Corporate Bulletin # 106301R) and completely follow the instructions. After following procedures in bulletin 91-T-35A (Corporate Bulletin # 106301R), install new PCM calibration (refer to this bulletin for correct calibration number). The manufacturer's label on the driver's door provides vehicle build date.

On vehicles built after January 1, 1992, proceed to Steps 1 through 3 of this bulletin. If the condition still exists after following the procedures in this bulletin and the new calibration has been installed, refer to Technical Information Bulletin 91-T-35A and completely follow the bulletin instructions.



PROCEDURE:

1. Using the Scan tool, check for PCM EC/TC codes and flags. If codes or flags are present, refer to the applicable diagnostic charts in the "Electronic Engine Controls Service Manual," and repair the condition. After verifying that condition has been repaired, download the new calibration according to Step 3.

2. If no codes or flags are present, monitor Scan tool data and verify all parameters are within specification. Refer to "Electronic Engine Controls Service Manual." If parameters are not within specification, repair the condition. After verifying that condition has been repaired, download the new calibration according to Step 3.

3. If no codes or flags are present and Scan tool data is within specification, download new calibration using the Saturn Service Stall System or refer to the "Electronic Engine Controls Service Manual."

IMPORTANT:
Before installing a new calibration, make a note of the transaxle calibration installed, and download the same transaxle calibration with the correct engine calibration.





1992 New Calibration - SOHC (LKO) Engines



IMPORTANT:
After the new calibration has been installed, vehicle must be driven until operating temperature is reached. This allows the PCM to relearn variations in the fuel system electronic controls that improve driveability and engine idle.

IMPORTANT:
Verify that customer complaint has been repaired. If problem still exists, refer to diagnostic procedures in the "Fuel/Air Intake/Exhaust Service Manual," and "Electronic Engine Controls Service Manual."

CLAIM INFORMATION:





To receive credit for this repair, submit a claim through the Saturn Dealer System