Firm Transmission Shifts, Shudder/Chuggle, Transmission Wont Downshift on Deceleratio [Archive] - GrandAmGT.com Forum

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iceman
06-18-2003, 08:25 PM
Firm Transmission Shifts, Shudder/Chuggle, Transmission Wont Downshift on Deceleration, Service Engine Soon Light Illuminated, DTC P0742 Set (Perform Diagnostics and Replace TCC PWM Solenoid) #02-07-30-039C - (06/12/2003)
Firm Transmission Shifts, Shudder/Chuggle, Transmission Won't Downshift On Deceleration, Service Engine Soon Light Illuminated, DTC P0742 Set (Perform Diagnostics and Replace TCC PWM Solenoid)
2003 Buick Century, LeSabre, Park Avenue, Regal, Rendezvous

2003 Cadillac DeVille, Seville

2003 Chevrolet Cavalier, Impala, Malibu, Monte Carlo, Venture

2003 Oldsmobile Alero, Aurora, Silhouette

2003 Pontiac Aztek, Bonneville, Grand Prix, Grand Am, Montana, Sunfire

with 4T65E Transaxle (RPOs MN3, MN7, M15, M76), 4T40E/4T45E Transaxle (RPOs MN4 or MN5) or 4T80E Transaxle (RPO MH1)

with Transaxle Manufacturing Julian Dates Between 219 and 3048

This bulletin is being revised to clarify information regarding the 4T80E transaxle. Please discard Corporate Bulletin Number 02-07-30-039B (Section 07-Transmission/Transaxle).

Condition
Some customers may comment that the transmission shifts hard, a shudder/chuggle is felt on deceleration or the Service Engine Soon (SES) light is illuminated.

A technician may find DTC P0742 set.

Customers with 4T80E transaxles may also comment on a "bump" feeling at approximately 61-68 km/h (38-42 mph) when they lift and then tip into the throttle. There may also be a concern of whine noise in 3rd or 4th gear with or without the Service Engine Soon light/message displayed and with DTC P0742 set.

Correction
DO NOT REPLACE THE VALVE BODY AND PUMP ASSEMBLY.


Important
This test is not applicable to the 4T80E transmission. Instead, replace the TCC PWM solenoid on vehicles with a 4T80E transmission using published procedures for the vehicle being serviced.


Perform one of the following diagnostics:

Test drive the vehicle with the Tech 2 installed, Monitor Transmission Release Pressure. The Status will be YES until TCC applies and then the display will read NO. If during acceleration the status remains NO and the upshifts are harsh and during deceleration the vehicle shudders during downshifts, suspect the TCC PWM solenoid.
With the Tech 2 installed in the vehicle, start the engine. Build the vehicle on the Tech 2. Apply and firmly hold the service brake. Place the transaxle in D4 and command Drive 3 with the Tech 2. If the engine stumbles and/or stalls, suspect the TCC PWM solenoid.
Replace the TCC PWM solenoid using published procedures for the vehicle being serviced.

Parts Information
Transaxle Model
Part Number
Description
Qty

4T65E
24227747
Valve Assembly
1

4T45E

4T80E
24227792
Valve Assembly
1