HARSH, ERRATIC SHIFTS, NO GEAR OR GEAR STUCK ON MULTIPLE PCM. Saturn Saturn 1993

For 1990-2009 cars

# HARSH, ERRATIC SHIFTS, NO GEAR OR GEAR STUCK ON MULTIPLE PCM

#### SUBJECT: Harsh and/or Erratic Shifts, No Gear or Gear Stuck On, and Multiple PCM/TC Codes are Set - MP6/MP7 Automatic Transaxles (Replace Stuck Transaxle Control Actuator Valve)

Due to the addition of 1994 vehicles, extensive changes in procedures and the addition of PCM/TC codes 21 and 75, this bulletin supercedes bulletin 93-T-22, which should be discarded.

#### MODELS AFFECTED: 1993 and 1994 Saturn Sedans, Coupes and Wagons equipped with MP6 or MP7 automatic transaxles.

#### CONDITION:

---------- Some automatic transaxles may have harsh and/or erratic shifts, no gear or gear stuck on, and the malfunction indicator lamp (MIL) (SERVICE ENGINE SOON telltale lamp) may come on, and multiple diagnostic trouble codes (21, 22, 23, 24, 25, 75 and 78) may be stored in the PCM/TC.

#### CAUSE:

------ Some automatic transaxles may have been manufactured with iron sediment that migrates to the control valve body assembly causing transaxle control actuator valves to seize and/or the valves in the control valve assembly to stick or be sluggish to move.

#### CORRECTION:

----------- Refer to the following procedures to diagnose and repair the transaxle.

#### PROCEDURES:

-----------

1. Record the PCM/TC diagnostic trouble codes and "Slip Monitor" values. IMPORTANT: Prior to disconnecting the battery, the "Slip Monitor" values must be recorded.

2. Verify if the transaxle is stuck in a forward gear. Connect the Scan tool and observe the automatic transaxle turbine speed while performing the following:

#### NOTICE: When verifying if transaxle is stuck in a forward gear, move the vehicle to an unre- stricted area where vehicle maneuvers can be made without interruption. During this evaluation, as always, apply the brakes before shifting between gears.

Shift the transaxle into Reverse. If the vehicle will not move and the automatic transaxle turbine speed reads 0 rpm, the transaxle is stuck in a forward gear. Internal damage to the transaxle has occurred and a complete transaxle overhaul must be performed. Refer to the "Internal Inspection Procedure" in this bulletin. While applying the brakes, shift the transaxle into Neutral. If the automatic transaxle turbine speed reads 0 rpm, the transaxle is stuck in a forward gear. Internal damage to the transaxle has occurred and a complete transaxle overhaul must be performed. Refer to the "Internal Inspection Procedure" in this bulletin.

3. Test drive the vehicle to verify the complaint.

4. Follow the appropriate diagnosis procedures in the "Automatic Transaxle Service Manual" for any diagnostic trouble codes that are set. If the repair requires transaxle control actuator valve or control valve body assembly removal, inspect the transaxle control actuator valves for a ring of very fine iron sediment (silver to dark gray in color) that may be surrounding the transaxle control actuator valves.

#### IMPORTANT: On vehicles with mileage greater than 48,270 km (30,000 miles), a ring of very fine iron sediment (silver to dark gray in color) is common and should be considered normal.

5. If no ring of iron sediment exists, replace the stuck transaxle control actuator valve only. For proper replacement, follow procedures in the "Automatic Transaxle Service Manual."

6. If a ring of iron sediment is present , perform the following inspections to determine if internal damage to the transaxle may have occurred. If any of the following conditions exist, refer to "Internal Inspection Procedure" in this bulletin.

Previously recorded slip monitor values are at 600 kPa. Transaxle fluid smells burnt.

Inspect the control valve body assembly and transaxle control actuators.

o Control valve body assembly shows heavy build-up of fine black material in the recesses of the upper control body, under the actuator retainer (cover).

o Strings of fine black material can be seen on the transaxle control actuator armature stop.

Inspect the clutch housings through the top of the transaxle case.

o Clutch housing lube holes have a shadow around them which is darker than the surrounding material.

o Clutch housing shows discoloration due to excessive heat.

#### IMPORTANT: The 4th clutch housing normally shows heat treat discoloration at the park gear. If none of the conditions in stefi 6 exist, repair the transaxle according to "Flushing Procedure" in this bulletin.

Flushing Procedure

#### NOTE: For the following procedures, refer to the "Automatic Transaxle Service Manual."

1. Disassemble the control valve body assembly.

2. Clean all passages and valves within control valve body assembly.

3. Dry all parts.

4. Verify that all valves within control valve body assembly move (slide freely) from their own weight within the control valve body assembly bores.

a. If the valves move freely within their bores, proceed to step 5.

b. If any of the valves do not move freely within their bore, replace the control valve body assembly, then proceed to step 7.

5. Install any new transaxle control actuator valves that have to be replaced due to a ring of iron sediment.

6. Reassemble the control valve body assembly. Do not install the control valve body assembly into the transaxle at this time.

7. Remove transaxle rear cover.

8. Disassemble the clutch feed tubes from the rear cover and flush with clean carburetor or brake cleaner.

9. Flush the passages inside the rear cover with clean carburetor or brake cleaner and blowout passages with compressed air.

10. Disconnect the transaxle cooler pipes from the transaxle and flush the transaxle cooler and pipes using the Oil Line Cooler Flusher SA9165T, following the instructions included with the tool.

11. Drain transaxle fluid and replace transaxle oil pressure filter. Fill transaxle with transaxle fluid to specifications in service manual.

12. Assemble the transaxle and test drive to verify repair. Refer to the "Test Drive Procedure" in this bulletin.

Internal Inspection Procedure

If it has been determined that internal transaxle damage has occurred, a complete transaxle reconditioning must be performed. Follow the procedures in the 'Automatic Transaxle Service Manual," with emphasis on the following inspections and cleaning procedures.

1. Clean and inspect the rear cover, transaxle cooler pipes, and control valve body assembly as described in the "Flushing Procedure" in this bulletin

2. Completely disassemble the transaxle case and clean using parts cleaning solvent and allow to dry. Flush all internal passages with clean carburetor or brake cleaner and blow out with compressed air. Using a dry rag, wipe any magnetic material from the turbine speed sensor.

3. Completely disassemble the input and output shaft assembly. Flush the internal passages with clean carburetor or brake cleaner and blow out with compressed air.

4. Completely disassemble the clutch housings and discard the clutch pistons.

5. Inspect the clutch plates for possible damage. Replace damaged clutch plates if any of the following conditions exist: o If the friction material on the clutch plates has pulled away or started to pull away from the steel back.

o The lettering is not visible on the friction material. o Heat distress is visible on the steel backing.

#### IMPORTANT: It is not necessary to replace the clutch housing and/or gear and hub assembly if they show discoloration. Replace them only if their is evidence of physical damage.

6. Clean the clutch housings with clean carburetor or brake cleaner.

#### IMPORTANT: Clutch plates are to be cleaned using clean transaxle fluid only. Do not use sol- vents to clean clutch plates.

7. Remove the oil pump and stator shaft assembly from the converter housing and inspect the drive gear hub bore of the converter housing for damage. The drive gear hub bore should have uniform machining marks and should not be scored. Look for any cracks at the oil pump drain hole. Replace converter housing if damaged.

8. Inspect the pump drive and driven gears and wear plate for signs of pitting. Inspect the pump body for any scoring or cracks. Replace the pump assembly if damaged.

9. Clean the converter housing using parts cleaning solvent and allow to dry. Flush all internal passages with clean brake cleaning fluid or carburetor cleaner and blow out with compressed air. Using a clean dry rag, wipe any iron sediment from the vehicle speed sensor.

10. Inspect the torque converter pump drive hub for any scoring or pitting. Replace the torque converter if damaged.

11. Drain as much transaxle fluid from the torque converter as possible. (A small amount of transaxle fluid will remain in the torque converter.) Check torque converter end play using SA9163T, following procedures in the 'Automatic Transaxle Service Manual." Replace the torque converter if the end play is not within specification. IMPORTANT: The torque converter should be replaced if a hard part (i.e. gear or shaft) failure or a pump failure has occurred in the transaxle.

12. Assemble the transaxle.

#### IMPORTANT: Replace the transaxle suction filter and pressure filter. Wipe the magnet clean with a clean dry rag.

13. Install transaxle and test drive to verify repair. Refer to "Test Drive Procedure" in this bulletin.

Test Drive Procedure

After completing the flush procedure or internal inspection, test drive the vehicle using the following procedure.

1. Clear all PCM codes.

2. Start vehicle and bring transaxle temperature up to operating temperature of 90* C (194' F).

3. Shift the vehicle into D2 and start driving:

o At 32 km/h (20 mph), accelerate with 30 percent throttle to 40 km/h (25 mph). Let off on the throttle and decelerate back to 32 km/h (20 mph). Perform this procedure six times.

o Read the slip monitor for 2nd clutch.

4. Shift the vehicle into D3:

At 56 km/h (35 mph), accelerate with 30 percent throttle to 72 km/h (45 mph). Let off on the throttle and decelerate back to 56 km/h (35 mph). Perform this procedure six times.

#### IMPORTANT: Do not allow a 3 - 2 downshift. If a downshift occurs, it will be necessary to reduce the throttle slightly.

o Read the slip monitor for 3rd clutch.

5. Shift the vehicle into D4:

o At 64 km/h (40 mph), accelerate with 30 percent throttle to 80 km/h (50 mph). Let off on the throttle and decelerate back to 64 km/h (40 mph). Perform this procedure six times.

#### IMPORTANT: Do not allow a 4 - 3 or 4 - 2 downshift. If a downshift occurs, it will be necessary to reduce the throttle slightly.

o Read the slip monitor.

If any of the slip monitor values are greater than zero, internal damage to the transaxle may exist, and the transaxle must be inspected according to the "Internal Inspection Procedure" in this bulletin.

If all of the slip monitor values are zero, the vehicle is repaired and can be returned to the customer.

#### PARTS REQUIREMENTS:

Refer to Service Parts Catalog for any parts replaced

#### 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 Replace Transaxle Control K6547 1.8 hrs Actuator Control Valve Add 0.2 hrs with ABS

VW Transaxle Control Valve T9649 5.3 hrs Body Assembly Removal/ Add 0.2 hrs Clean/Inspect, Rear Cover with ABS R&R/Clean, Clean Transaxle Cooler, Install New Transaxle Control Valve Body Assembly, Change Fluid and Pressure Filter and test drive vehicle

VW Transaxle Control Valve T9650 5.8 hrs Body Assembly Removal/ Add 0.2 hrs Clean/Inspect and with ABS Reassemble, Rear Cover R&R/Clean, Clean Transaxle Cooler, Change Fluid and Pressure Filter and test drive vehicle

#### NOTE: For internal repairs, refer to the proper model year in the "Electronic Labor Time Guide" for the most appropriate labor operation code and time.

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.