Two problems related to automatic transmission torque converter have been reported for the 2003 Chevrolet Trailblazer. The most recently reported issues are listed below.
2003 chevy Trailblazer ext transmission problems: transmission shifted very hard from 1st to 2nd gear and 2nd to 3rd gear after vehicle had been driven for about 1 hour. This occurred several times over the course of a month. Finally, the "service engine soon" light came on during about the 4th occurrence. Called onstar and they stated that there was a powertrain/transmission problem that should be addressed soon. Took vehicle to several transmission shops and was told that the code was an 1870 "general transmission slippage" code. Transmission shop indicated that the problem is a result of a torque converter failure. Transmission is now being replaced at a transmission shop with cost of approximately $2900. Vehicle has just under 60,000 miles. It is my intense feeling that this type of replacement should not be necessary on a $38,000 vehicle with this low of miles.
8 times to dlr with same problem, this time worse. Times prior were torque converter fault codes, also not allowing cruise to engage. High rpm's and will not shift into overdrive. Lunging on first and second gear when accelerating from a stop. Dealer just replaced transmission (21,000 miles) and now won't shift at all. Purchased 6 months ago. 2003 chevy Trailblazer ext 4x4.