1997 gmc safari awd Idles fine, but accelerating when the engine is cold, sputters and jerks until the engine warms up. Then runs fine. Service engine soon is always on. Transmission shop says ok.

Knowing the code number "p****", will help immensely! The computer is tied in to the many sensors in the car, which can isolate a problem and help in understanding the underlying issue. Sometimes, a code can send a vehicle into, "safety mode", not dying this is your case, but this could make you feel as though the vehicle is done, when it could be something as simple as a solenoid or sensor. If they gave the p code. Please enlighten me, as it can help a lot. Yes, your transmission may be fine, but the signal it is sending the computer may make it seem very serious!. Always willing to help. You can have a local auto parts store pull the code for free if you don't have access to a scanner. There may be more than 1 code. Knowing the code number "p****", will help immensely! The computer is tied in to the many sensors in the car, which can isolate a problem and help in understanding the underlying issue. Sometimes, a code can send a vehicle into, "safety mode", not dying this is your case, but this could make you feel as though the vehicle is done, when it could be something as simple as a solenoid or sensor. If they gave the p code. Please enlighten me, as it can help a lot. Yes, your transmission may be fine, but the signal it is sending the computer may make it seem very serious!. Always willing to help. You can have a local auto parts store pull the code for free if you don't have access to a scanner. There may be more than 1 code.

It could be an egr valve. But won't know without numbers. Write them down. Don't let the shop keep you in the dark. It could be an egr valve. But won't know without numbers. Write them down. Don't let the shop keep you in the dark.

It throws the same p0712 code twice.
which sensor do I replace and where is it located? It throws the same p0712 code twice. which sensor do I replace and where is it located?

That code points to the transmission fluid temperature sensor. Most likely, the sensor is bad, however, you may be due for a transmission fluid and filter replacement depending on the mileage on the vehicle. Knowing the code helps so much. To check the transmission fluid level, you must bring he vehicle up to temperature, and check it in park or nuetral. Most of the time you will only be down less than a quart of transmission fluid. If you notice that the fluid you are checking is dark or brownish in color, it is definately time for a flush and change. In most gm vehicles, it is smart to change the transmission filter at the same time, which will mean dropping the pan and replacing it with new red fluid. Make sure you change it with the right gm fluid for your application. If the fluid has been changed recently, more than likely, the sensor is throwing off the signal to the computer, which will make the vehicle think there are problems and cause it to run, let us say, less than desirable. So, the answer to your question is to check your fluid, make sure it is full and red in color, if not, the replacement of the sensor will clear up the problem in most cases. Thank you so much for the code!!!! It brings the guess mode down quite a bit, good luck, and just so you know, gm trannys are petty good and maintained will last quite some time. Most service is done every 50,000 to 75,000 miles tops. If you have not performed this, it is due or, if you need to change the sensor, it is relatively inexpensive, good luck! That code points to the transmission fluid temperature sensor. Most likely, the sensor is bad, however, you may be due for a transmission fluid and filter replacement depending on the mileage on the vehicle. Knowing the code helps so much. To check the transmission fluid level, you must bring he vehicle up to temperature, and check it in park or nuetral. Most of the time you will only be down less than a quart of transmission fluid. If you notice that the fluid you are checking is dark or brownish in color, it is definately time for a flush and change. In most gm vehicles, it is smart to change the transmission filter at the same time, which will mean dropping the pan and replacing it with new red fluid. Make sure you change it with the right gm fluid for your application. If the fluid has been changed recently, more than likely, the sensor is throwing off the signal to the computer, which will make the vehicle think there are problems and cause it to run, let us say, less than desirable. So, the answer to your question is to check your fluid, make sure it is full and red in color, if not, the replacement of the sensor will clear up the problem in most cases. Thank you so much for the code!!!! It brings the guess mode down quite a bit, good luck, and just so you know, gm trannys are petty good and maintained will last quite some time. Most service is done every 50,000 to 75,000 miles tops. If you have not performed this, it is due or, if you need to change the sensor, it is relatively inexpensive, good luck!