TRANS. CODE 34 &47

1992 Saturn SC2 • FWD Automatic • 168,000 miles

I have a 1992 saturn sc2. When using sunpro scan tool it displays trans. Codes 34 & 47. Also when check engine light is on there is no speedometer. When you clear the check engine light with scan tool the speedometer will work again and car runs fine. As soon as light comes back on there is no speedometer car run and shift lousy

thank you mark
December 3, 2010.

34 is internal communication fault manfacture says replace PCM the 47 find no code 47 could it be 41? Cause that is for Vehicle Speed Sensor and that can cause the problem

Dec 3, 2010.
Code 34 is map sensor low voltage there is no 34 for transmission the only code 47 I saw was for anti lock brake's and it's for left front motor circuit current low. So does that scan tool able to read abs code's?Also do you have a multimeter?I don't see why you would loose the speedometer from the code's you have listed. You don't have a code 11?

Dec 3, 2010.

DTC 34 is set when information from the PCM/EC is not being received by the PCM/TC.

* Some PDT or SSS tests such as a QDM test, PCM reprogramming, or adaptive reset may cause DTC 34 to set.


IMPORTANT: Record all PCM diagnosis diagnostic trouble codes/information flags and include with repair order.

* Clear all diagnostic trouble codes/information flags, test drive the vehicle and if DTC 34 resets, replace the PCM.

* If this code is present and the only customer complaint is driveability, replace PCM.
This second one is for code 47 in the transmission.
The first one is for code 34 in the transmission usually when you get code's in your transmission you will get a code 11 flash out on your service engine soon light that code mean's you have transmission code's.

Dec 4, 2010.