04 Silverado Transmission Lag

[GM Truck Family Man]

At three separate times in the last couple of months I have noticed that the transmission does not downshift when stopping at a stoplight. On acceleration the transmission seems to still be in a higher gear. The engine RPMs increase but the truck doesnt move, then will suddenly downshift to first and then take off. The truck is a 04 Silverado 1500 Crew Cab Z71. Any ideas? Thanks!

[GM-Tech]

This *may* help...

 

 

4L60-E/4L65-E Automatic Transmission Second Gear Start, Lack/Loss of Power When Accelerating from a Stop (Reprogram Powertrain Control Module (PCM)) #05-07-30-013 - (May 9, 2005)

 

2004-2005 Cadillac Escalade

 

2004-2005 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe

 

2004-2005 GMC Savana, Sierra, Yukon

 

2004-2005 HUMMER H2

 

with 4L60-E (RPO M30) or 4L65-E (RPO M32) Automatic Transmission

 

Condition

Some customers may comment on a slip on launch, low power on a launch or a second gear start when accelerating from a stop.

 

This condition is usually very intermittent, occurring only once in a few thousand miles of driving.

 

A Tech 2 or VDR snapshot of the event may show 2nd gear being commanded for approximately two seconds, then 1st gear commanded as would be expected.

 

Cause

This condition may be caused by an intermittent VSS signal, which causes the PCM to command second gear.

 

Important: There are other conditions that can cause the transmission to start in a gear higher than first. The following are a few of these conditions.

 

 

• Some DTCs can cause the transmission to start in a higher gear. Check for the presence of DTCs and repair as appropriate before proceeding.

 

• Debris on top of the spacer plate or in the valve body or a leaking shift solenoid can cause a 4L60-E or 4L65-E transmission to start in a gear higher than first. A start in a higher gear caused by any of these conditions typically occurs with much greater frequency. Refer to Service Bulletin 01-07-30-036D or newer for diagnostic information of these conditions.

 

• Placing the shift lever in the D2 position will cause a 4L60-E or 4L65-E transmission to start in second gear.

 

 

Correction

Important:

 

• This bulletin ONLY applies to 2004-2005 models year vehicles listed above.

 

• Some DTCs can cause the transmission to start in a higher gear. Check for the presence of DTCs and repair as appropriate before proceeding.

 

 

Using a scan tool, check for the presence of DTCs. If DTCs are present, refer to the appropriate SI Document before proceeding with this calibration.

Important: These calibrations also contain the 2-3 shift clunk calibration as detailed in bulletin 05-07-30-012.

 

 

Technicians are to reprogram the PCM with an updated software calibration. This new service calibration was released with TIS satellite data update version 5 or later available May 1, 2005. Refer to Service Programming System (SPS) in Vehicle Control Systems in the appropriate SI Document.

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

Description

Labor Time

 

J6355

Module, Powertrain Control - Transmission Reprogramming

Use Current Published Labor Time

 

 

 

 

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.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

 

© Copyright General Motors Corporation. All Rights Reserved.

[BIGDOGx]

Nice thanks gm-tech i have been having this problem i think, mostly happens when i shift from any gear to drive and feels like it delay shifts and slip into gear.I asked the service manager and he said he never heard of this problem, looks like i need to give them a call.

[GM-Tech]

mostly happens when i shift from any gear to drive and feels like it delay shifts and slip into gear.

 

I don't think that's even close to being related to what the TSB is talking about.

[bigdogxx]

mostly happens when i shift from any gear to drive and feels like it delay shifts and slip into gear.

 

I don't think that's even close to being related to what the TSB is talking about.

 

<{POST_SNAPBACK}>

 

 

 

 

Actually it just did this problem also, at a stop light and it felt like a start in 2nd then i felt a clunk then it went into 1st and caught.This tranny is acting very strange it should engage into gear right away not delay and now it is doing exactly what this tsb is saying.Oh well it goes in for a check up on saturday and if it is just a pcm update they can preform it regardless and i hope it clears thing up.

[Rough]

Found this with a search, what happened with your truck?

My 2005 Silverado 5.3, 4X4 occasionally starts in second gear per the bulletin [once every couple of months] but yesterday it set a code and in addition to starting in second it is not shifting properly. I parked it until I can get it to the dealer, does this sound like electrical or mechanical? The truck is still under warranty so I'm concerned about the dealer just doing a temporary fix only to have the problem return after the warranty is up. The truck only has 15k highway miles but it won't take much more of this nonsense for me to go back to Ford or possibly look at the imports.

 

Thanks for your help.

[GM-Tech]

The truck is still under warranty so I'm concerned about the dealer just doing a temporary fix only to have the problem return after the warranty is up.

 

I'm not sure how one would do a temporary fix that will only last a certain amount of time. Either you fix it or you don't. It would take pretty extensive planning to make a repair that is designed to fail sometime down the road.

 

As to you question... sounds like it's possibly an electrical control problem.

[Rough]

The truck is still under warranty so I'm concerned about the dealer just doing a temporary fix only to have the problem return after the warranty is up.

 

I'm not sure how one would do a temporary fix that will only last a certain amount of time. Either you fix it or you don't. It would take pretty extensive planning to make a repair that is designed to fail sometime down the road.

 

As to you question... sounds like it's possibly an electrical control problem.

 

<{POST_SNAPBACK}>

 

 

 

 

How about a half assed repair where maybe the mechanic repairs an electrical problem and the vehicle seems fine except several years of life have been burned out of the clutches or band due to slippage caused by the electrical problem?

Short of a teardown or at least pulling the pan there isn't any way to determine what collateral damage has occured.

 

Thanks again for your help.

[Rough]

FYI, the dealer replaced the ignition switch, go figure as the truck otherwise ran fine. 1 week in, truck runs and shifts well.

 

Thanks again.