hi, i have a hhr 2006. after 15 to 20 minutes , the transmission rides rough, like moving in just one gear, the lock actuators sound, but the locks does not move, the speedo goes up and down like crazy, this only happens when any gear is selected, it does not happen while in parking, it have a p0700 code, only gave me the code once. some told me it could be a bad bcm or bad tcm. any suggestions?. when it gets cold again you can ride it with no faults noted until it gets hot again.

 

The P0700 code is a TCM (transmission code module). I would check all the wiring going to the module first, it may not be getting a reading and thus, causing the fault.

 

thanks for the reply, i took the plug from the tcm and cleaned with contact cleaner and also cleaned the tcm plug, no change. one mechanic told me it could be the bcm because of the locks and speedo issue. he said only the bcm control them and also a bad bcm could send an erroneous signal to the tranny and make it fault.

 

The code you have is an internal fault in the tcm I don't think the body controller can induce that code. Here is an interesting bulletin that I found from GM.

It has been found during warranty part reviews of the TCM (Transmission Control Module) at the Warranty Parts Center that the TCM is possibly being shorted to battery voltage during vehicle diagnosis and/or repairs when the vehicle is being serviced.

It has been found that if the positive battery jump start post/terminal cover is removed and/or missing, and the TCM comes into contact with the positive battery jump start post/terminal during diagnosis and/or service, the TCM will be damaged and will require replacement.

This TSB applies to the following vehicles:

* 2005-2010 Chevrolet Cobalt

* 2006-2010 Chevrolet HHR

* 2006-2010 Chevrolet Express

* 2006-2010 GMC Savana

* 2005-2006 Pontiac Pursuit (Canada)

* 2007-2010 Pontiac G5

* 2005-2007 Saturn Ion

PRECAUTIONS

Prior to removing the TCM from its mounting bracket, disconnect the negative battery cable. If service requires the negative battery cable to be installed for diagnostic purposes, unplug the TCM before it is removed from its mounting bracket. Unplugging the TCM will eliminate the possibility of damaging the module during diagnosis and/or repair.

The control module may be damaged when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control, using battery booster cables, or when charging the vehicle’s battery. DO NOT use the TCM or its mounting bracket/fasteners as a ground connection when jump-starting.

The location of the positive battery jump post/terminal for each vehicle (excluding Express and Savana) is shown in the following illustrations. Do not allow any part of the TCM to come into contact with the positive battery jump start post/terminal.

 

http://www.ebay.com/itm/GM-Transmission-Control-Module-New-OEM-24234503-TCM-Computer-Trailblazer-/360865266980?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2006%7CModel%3AHHR&hash=item54053efd24&vxp=mtr

 

when i went to ebay it was sold, thanks

 

great info, thanks

 

Check Amazon. I've seen them there also between $60 and $135 new.

 

ok ill check amazon