Check Engine Light on '94 Jeep Grand Cherokee

Question

How do I get Check Engine Light codes (ODB-I) from a '94 Jeep Grand Cherokee, and where can I look them up?

Answer 1

This blog is a nice reference:
http://check-engine-light-codes.blogspot.com/2006/04/chrysler-1985-95-obd1-code-self.html

It explains how to check:

Within a period of 5 seconds, cycle the ignition keyON-OFF-ON-OFF-ON.

Count the number of time the MIL (check engine lamp)on the instrument panel flashes on and off. The number of flashes represents the trouble code. There is a short pause between the flashes representing the 1st and 2nd digits of the code. Longer pauses are used to separateindividual 2-digit trouble code.

An example of a flashed DTC is as follows:

-Lamp flashes 4 times, pauses, then flashes 6 more times. This denotes a DTC number 46. -Lamp flashes 5 times, pauses, then flashes 5 more times. This indicates a DTC number 55. DTC 55 will always be the last code to be displayed.

And has a list of codes:

88 display used for start or test
11 camshaft signal or ignition signal, no reference signal during cranking
12 memory to controller has been cleared within 50-100 engine starts
13 map sensor not detecting any change during test
14 map voltage too high or too low
15 vehicle speed sensor, no signal detected
16 knock sensor circuit. open or short detected
17 low engine temperature, possible thermostat fault
21 oxygen sensor signal, neither rich or lean detected
22 coolant sensor voltage low
23 air charge voltage high/low detected
24 throttle positioner sensor voltage high/low
25 automatic idle speed motor driver circuit, short or open detected
26 injectors 1,2,3 peak current not reached
27 injector control circuit does not respond to control signal
31 purge solenoid circuit, open or short detected
32 egr solenoid circuit, open or short detected
33 a/c clutch relay circuit, open or short detected
34 speed control servo solenoid, open or short detected
35 radiator fan control relay circuit, open or short detected
36 wastegate solenoid, open or short detected37 part throttle unlock(PTU) circuit, open or short detected
41 charging system circuit not responding to control signal
42 fuel pump or auto shutdown (ASD) relay voltage sensed at controller
43 ignition control circuit not responding
44 battery temperature voltage circuit problem
45 turbo boost limit exceeded-map sensor detects overboost
46 battery voltage too high
47 battery voltage too low
51 air/fuel at limit
52 logic module fault
53 internal controller failure
54 camshaft reference circuit not detected
55 end of message
61 baro read solenoid, open or short detected
62 emr mileage not stored
63 eeprom write denied
64 flex fuel sensor signal out of range
65 manifold tuning valve, open or short detected
66 no ccd messages
76 ballast bypass relay, open or short detected
77 speed control relay, open or short detected 

Once you have the code you probably could search online if this list is not complete.