Jeep Grand Cherokee, 1996, 4.0, 4X4. I've been using the ignition key method to retrieve codes and was afraid of wearing out my ignition key (also tired of disconnecting the battery to clear codes) so I broke down and bought a code reader. Ancel AD310. When I use the ignition method to retrieve codes I get 12 and 55. The code reader says there are no codes. Did I buy the wrong code reader? Is there something wrong with my Jeep? Something wrong with the code reader? How do I diagnose a problem with the diagnosing tool itself? Thank you everyone for helping out unknowledgeable people like myself.

 

1996 might not be fully OBDII. I don't know about tthe Grands, but on the Cherokees, 96 was a bastard year. Some had the connector but were not really OBDII compliant. Have you had a shop try to read codes?

 

If your pulling codes with the ALDL connector you’re OBD1 so yes wrong reader but useful if you have obd2 vehicles .

 

Thanks for the replies!! Very much! So it looks like I wasted $35. I could have sworn I read somewhere that '96 Grand Cherokees use OBD2. The port on my Jeep is the same as an OBD2 port. Now I'm looking for an OBD1 scanner for Chryslers. I've found them for Ford and Chevy but can't find for Chrysler. Any ideas? Thanks again!

 

Others are right, it is NOT OBD-II, it's just OBD-I (the federal NHTSA requirement didn't happen until 1997). When my parents had a '96 Grand Cherokee ZJ, VEIP (MD's emissions testing program) always did the tailpipe emissions test instead of the OBD-II emissions test, and that's how I know the '96s didn't have OBD-II yet. I think you have to count the number of times the 'Check Engine' lamp flashes. It's like morse code, with a two-digit code: the light will begin to flash rapidly, then pause, then start flashing rapidly again. If you get Code 55 (5 Rapid Flashes, Pause, and 5 Rapid Flashes Again), then that indicates 'End of Sequence', and nothing is wrong. There's a list of codes online (somewhere!). If you don't get the code written down the first time, just do the key sequence again, or however many times you need to until you get it. The Code 55 ('End of Sequence') means that all the codes have been read, and there will be a short pause between the second digit of each code and the first digit of the next code.

Hope this helps, it worked on my '94 Grand Cherokee ZJ.

 

Code 12 is "battery power to PCM has been disconnected within the last 60 starts."