Intermitent Transmission Issue

[JTNC]

Hello guys,

 

This has only happened twice but i'm a little concerned since I am at 34k miles.

 

On two occasions now when stopped at a light the tranny hesitates to grab or engage when taking off. I will give it the gas and it feels almost like the brake is on then I will feel the tranny grab and we take off like normal. it usually doesn't do this and runs and shifts fine otherwise. The first time was Friday night and the second just now on the way home from dinner. Strange that the occurences were so far apart.

 

Is the powertrain warranty on the truck only 3/36k? That's what has me worried.

 

I did a search and read about 158,000 tranmission threads for 2 hours but didn't find any that sounded like my problem.

 

Any opinions?

 

Thanks.

 

-Jerry

[mdub]

If it makes you feel any better, I've noticed the exact same issue on my '03. Very rare though, probably less than 4 times in 50k miles. Like you, I was very concerned the first time. No serious mechanical problems have resulted though, so I'm beginning to think it's just some random timing glitch.

[JTNC]

Thanks. Anyone else?

[seadoons]

I have had the same thing happen to me on my 2002. It has maybe happened 5 times in the 6 years that I have owned it. Like it was said above, it really concerned me the first time it happened but I haven't had any other problems with the tranny besides those 5 times. The tranny has almost 110,000 on it.

[CapitalTruck]

This is probably your issue. I have had this same problem, never took it in though to have it fixed. It's probably done it about 5 times in 73,000 miles (on my 04). It feels like a major hesitation or stall when this happens.

 

Engine Controls - 4L60E/4L65E A/T 2nd Gear Start

 

Bulletin No.: 05-07-30-013

 

Date: May 09, 2005

 

TECHNICAL

 

Subject:

4L60-E/4L65-E Automatic Transmission Second Gear Start, Lack/Loss of Power When Accelerating From a Stop (Reprogram Powertrain Control Module (PCM)

 

Models:

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.

 

1. 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.

 

2. 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.

[wilkes65]

Same exact thing happened to my fathers truck, he took it in and they could not find anything wrong . He also had about 34,000 miles on it. He decided to get rid of the truck because he was worried it would go out after 36,000 miles.

[wages999]

My truck has done the same thing from time to time. Once when towing another truck on a trailer I slowed for a light. The light changed and I got back on gas and the transmission didn't engage and let the motor rev freely. I slowed more and it finally engaged. Had it in the dealer a couple of times and they said that there were no error codes for the transmission.

[JTNC]

Thanks for all of the replies guys.

 

Special thanks to CapitalTruck for all of the details.

 

I'm thinking I should take it in to see if there are any tranny codes. At least then I will be on record of having a problem.

[pm26]

This issue has apparently been resolved by the end of 2005 model production. I have not noticed anything like that with my '06 -yet.