1991 Chevy K1500 error code??

[mlholmes74]

I just did a diagnostic test on my truck and after the 12 code, it flashed 3 times, pause, 3 times, pause, 3 times, pause, 3 times, pause, 3 times, pause. Unsure of what this actually means?? The problem I'm having is hesitation when giving gas, once you get going it runs fine??

[dougbfresh]

http://answers.yahoo.com/question/in...1171456AAUT8Y1

[Saltmine]

Code 12 means the computer has run a self-test and found no pending codes or anything out of spec. It's supposed to flash 3 times, perfectly normal.

Your "check engine light" is off when it's running, right. #12 means no codes stored

[mlholmes74]

after it flashed code 12 three times, thats when it did the 3 flashes and then pause 6 times, and then the code 12, (flash, pause, flash flash), the check engine light comes on and off when driving it.

[dougbfresh]

If the CEL light comes on you have issues. If it's on/off while driving it's most likely a misfire. You need to check codes right after this happens.

[carsandcycles]

If your check engine light is on and you go into diagnostic mode, a code 12 will flash, which is telling you that the ECM is functioning. After the 12, if your ECM has recorder an error code it will flash the code three times (go to the next code if there is one) then complete the sequence with a 12 (indicating that all codes have been conveyed). It appears that you have an error code of 33 that needs to be addressed. Code 33 appears to be a MAP sensor error (signal too high).