Where is the diagnostic center for 1993 Jeep Grand Cherokee?

Answer 1

On 97 and earlier models of GC the engine is equipped with a diagnostic center known as the PCM or Powertrain Control Module (its basically a "black box thingy". The PCM is fed information from various sensors on the engine such as the camshaft position sensor, crankshaft position sensor, engine coolant temp sensor, intake air temp sensor, O2 sensor, throttle position sensor etc etc etc. Theres lots here that can go wrong over the years unfortunately.

Trouble codes can be retrieved from the PCM via a modular plug located under the dash around the area left of the steering wheel using a scanning device.

You can also have the codes displayed via the number of flashes that the check engine light displays when you follow the following sequence to activate the diagnostic system:

Without starting the engine turn the key on, off, on, off and then on. The check engine light will begin to flash and you should have a piece of paper handy to write down the number of flashes since the number of flashes indicates the code. These are all two digit numbers. The first series of flashes will indicate the first digit and there will be a pause followed by a second series of flashes. If there are more than one code stored in the PCM there will be a longer pause and then the second code will begin to flash. Pretty crazy eh?

So, with hopefully the correct code in hand you can procede to the library to look in a Chilton or Hayes manual to see what this mysterious number means. It actually might be easier to just take the vehicle to a reputable repair place that has a scanner and let them hook you up.

I believe that this system is similar in comparison to what the Amiga game system was to the current Wii.......but I'll let you draw your own conclusions.

Good luck !!!!