NO REV. AND/OR SERVICE ENGINE SOON LIGHT ILLUMINATES. Saturn Saturn 1991

For 1990-2009 cars

# NO REV. AND/OR SERVICE ENGINE SOON LIGHT ILLUMINATES

#### SUBJECT: --------- No Reverse and/or "SERVICE ENGINE SOON" telltale Lamp Illuminated (Replace Input Shaft Pilot Hub and Seal Rings) All 1991 Saturns with Automatic Transaxles

#### CONDITION:

----------- No reverse gear or the vehicle moves in reverse for a few feet and then stops. The "SERVICE ENGINE SOON" telltale lamp may be illuminated by this condition. During diagnostics a PCM/TC Code 16, 18, 21, 22, 23 or 24 may be stored by the powertrain control module (PCM).

#### CAUSE:

------- The no reverse condition or an illuminated "SERVICE ENGINE SOON" telltale lamp with a stored PCM/TC Code 16, 18, 21, 22, 23 or 24 may be caused by the input shaft pilot hub seal rings being rolled. If the inner seal ring is rolled, 2nd/REV oll may leak to the 1st clutch causing 1st and reverse clutches to be on at the same time creating a no reverse condition. This condition may also cause the 1st clutch oil to apply 2nd clutch at all times causing a PCM/TC Code 16 (No 1st Gear) or PCM/TC Code 21 (2nd Gear Stuck On).

In extreme cases, a rolled seal ring may cause the oil to return to the sump, creating a significant loss of oil pressure to the 1st, 2nd, 3rd, or 4th clutches causing PCM/TC Codes 18 (No Gears), 22 (No 2nd Gear), 23 (No 3rd Gear) or 24 (No 4th Gear) to be set.

#### CORRECTIVE ACTION:

Transaxles built with change code "4" or higher, have a new input shaft pilot hub and input shaft hub seal rings which eliminate these conditions. All transaxles with a "O", "1", "2" or "3" change code need to have both components replaced when these conditions exist. If any of these conditions are present, and the transaxle change code is "4" or higher, refer to the "Powertrain Control Module Transaxle Control" in the "Automatic Transaxle Service Manual."

The change code number is part of the identification number found on the converter housing. (Refer to Figure 1 for change code location and description.) The transaxle change code can be checked with the transaxle in the vehicle.

#### PROCEDURE:

---------- If a customer brings in a vehicle with the previously described concern, it may be repaired by the following steps:

#### NOTE: The references to service manual sections in the following steps, are located in the "Automatic Transaxle Service Manual."

1. Remove the end cover following the "End Cover Gasket Replacement" removal procedures, located in the 'Automatic Transaxle In-Vehicle Repair" section.

2. Inspect the input shaft hub seal rings. If the seals are rolled, two notches will be visible along the groove edge, refer to Figure 2. Also, verify that the seal rings move freely in the grooves. If they do not move freely, the seal ring may be partially rolled.

a. If the seals are rolled, go to Step 3 of this Bulletin.

b. If the seals are not rolled, the transaxle should still be updated with the wider design seal rings and new hub. This will prevent any future problem with the old design seal rings. Since the concern will not be repaired by replacing the seal rings and hub, the cause of the concern must still be determined. Refer to the "Automatic Transaxle Diagnosis Charts" located in the "Powertrain Control Module - Transaxle Control" section of the "Automatic Transaxle Service Manual." Before going to transaxle diagnosis, refer to Step 3 of this Bulletin for seal rings and hub replacement procedures.

3. Remove the input shaft pilot hub following Steps 3-5 of the "Rear Cover Disassembly and Inspection" procedures, located in the "Automatic Transaxle Out-of-Vehicle Repair" section.

4. Install the new input shaft pilot hub and input shaft hub seal rings following Steps 1-14 of the "Rear Cover Assembly" procedures, located in the "Automatic Transaxle Out-of-Vehicle Repair" section.

5. Install the end cover following the "End Cover Gasket Replacement" installation procedures, located in the "Automatic Transaxle In-Vehicle Repair" section.

#### PARTS REQUIREMENTS:

21001684 1 - Gasket - End Cover to Case 21002372 1 - Gasket - Input Hub End Cover 21002684 2 - Seal - Input Shaft Hub Ring 21002498 1 - Hub - Input Shaft Pilot

#### CLAIM INFORMATION:

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

Labor Case Operation Type Description Code Time ----- -------------------------- -------- ------- VW Remove End Cover & Replace T9524 1.9 hrs Input Shaft Pilot Hub and Input Shaft Hub Seal Rings

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.