1050399
I have wished that there was a way to get a code reader for my 95YJ so I could check it from time to time. I bought one for my old Chevy truck and it plugged in under the dash and then you turned on the key and it would flash out the codes. One of my friends found out how to read the codes without a reader...note we have only tested this on our 95YJ's....both have the 2.5L but his is an auto...and mine was a standard when it had a transmission in it. My friend found out his O2 sensor was bad...he couldn't figure out how come his engine was running poorly and getting bad gas mileage. I looked it up on the net and found some more info...anyway here are the codes.
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font class="pn-sub">Quote:</font><HR></TD></TR><TR><TD><FONT class="pn-sub"><BLOCKQUOTE>
Start with the ignition off. Within five seconds, switch the key on,
off, on, off, on. (On is not start!)
The "check engine" light will flash. Count the flashes
Each code is a two digit code, so a (for example) 23 would be
FLASH FLASH---FLASH FLASH FLASH
It will never flash more than 9 times, watch for pauses!
55 is end of codes, 33 is normal if you dont have air conditioning.
Please note that some codes are NOT included below, this
is not a complete listing, but it IS very close to complete.
88 Start of test (This only appears on DRBII, it's not blinked out)
11 No ignition reference signal detected during cranking (bad hall
effect)
OR timing belt skipped one or more teeth; or intermittent
loss of either camshaft or crankshaft position sensor
12 Memory Standby power lost (battery cable disconnected)
13* No change in MAP from start to run
14* MAP sensor circuit open or shorted; voltage too low
15 No speed/distance sensor signal
16* Loss of battery voltage detected with engine running
17 Engine stays cold too long (bad thermostat)
21 Oxygen sensor signal out of range, possibly shorted
22* Coolant sensor signal out of range (or disconnected to set timing)
23 Intake air temperature signal out of range
24* Throttle position circuit out of range
25 Automatic Idle Speed (AIS) motor driver circuit shorted
or target idle not reached, vacuum leak found
26 Peak injector circuit voltage has not been reached
27 Logic module fuel circuit internal problem
OR
27 TBI injector does not respond properly to control signal
31 Evaporator Purge solenoid circuit open or shorted OR
Evaparator solenoid circuit
32 EGR system failure OR
Power loss lamp open or shorted
33 Air conditioning clutch relay circuit open or shorted
34 Speed control vacuum or vent solenoid circuits open or shorted
35 Cooling fan relay circuit open or shorted
36 Wastegate control circuit open or shorted
37 Shift indicator light failure, 5-speed (blown bulb) OR
Park/neutral switch failure
OR
37 Torque converter unlock circuit open or shorted, A-413 4-speed auto
41* Alternator field control circuit open or shorted
42 Automatic shutdown relay circuit open or shorted
42 Fuel pump relay control circuit
42 Fuel level unit - no change over miles
OR
42 Z1 voltage missing when autoshutdown circuit energized (whatever
that means)
43 Peak primary coil current not achieved with max dwell time
OR
43 Cylinder misfire
43 Problem in power module to logic module interface
44 No FJ2 voltage present at logic board
OR
44 Logic module self-diagnostics indicate problem
OR
44 Battery temperature out of range (see Note #1!)
45 Turbo boost limit exceeded (engine was shut down by logic module)
46* Battery voltage too high during charging or charging system
voltage too low
47 Battery voltage too low and alternator output too low
51 Oxygen sensor stuck at lean position
OR
51 Internal logic module fault ('84 turbo only)
52 Oxygen sensor stuck at rich position
OR
52 Internal logic module fault ('84 turbo only)
53 Logic module internal problem
54 No sync pickup signal during engine rotation (turbo only)
OR
54 Internal logic module fault ('84 turbo only)
55 End of codes
61 "Baro" sensor open or shorted
62 EMR mileage cannot be stored in EEPROM
62 PCM failure SRI mile not stored
63 Controller cannot write to EEPROM
64 Catalytic converter efficiency failure
65 Power steering switch failure
Copied from BC4x4.com
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
On my jeep the codes I got were 12, 33, and 55.
12 means you have recently unhooked your battery....mine had been unhooked till I tried the code thing.
33 means a problem with the A/C...this code will always pop up if you don't have A/C, which I don't
55 is the end of the codes...if all is well this is the only code you will get.
Just thought this was a cool thing....you other guys out there give this a try and tell me if it works on your YJ...I dunno about how the TJ system works...it may be different.
[addsig]
I have wished that there was a way to get a code reader for my 95YJ so I could check it from time to time. I bought one for my old Chevy truck and it plugged in under the dash and then you turned on the key and it would flash out the codes. One of my friends found out how to read the codes without a reader...note we have only tested this on our 95YJ's....both have the 2.5L but his is an auto...and mine was a standard when it had a transmission in it. My friend found out his O2 sensor was bad...he couldn't figure out how come his engine was running poorly and getting bad gas mileage. I looked it up on the net and found some more info...anyway here are the codes.
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font class="pn-sub">Quote:</font><HR></TD></TR><TR><TD><FONT class="pn-sub"><BLOCKQUOTE>
Start with the ignition off. Within five seconds, switch the key on,
off, on, off, on. (On is not start!)
The "check engine" light will flash. Count the flashes
Each code is a two digit code, so a (for example) 23 would be
FLASH FLASH---FLASH FLASH FLASH
It will never flash more than 9 times, watch for pauses!
55 is end of codes, 33 is normal if you dont have air conditioning.
Please note that some codes are NOT included below, this
is not a complete listing, but it IS very close to complete.
88 Start of test (This only appears on DRBII, it's not blinked out)
11 No ignition reference signal detected during cranking (bad hall
effect)
OR timing belt skipped one or more teeth; or intermittent
loss of either camshaft or crankshaft position sensor
12 Memory Standby power lost (battery cable disconnected)
13* No change in MAP from start to run
14* MAP sensor circuit open or shorted; voltage too low
15 No speed/distance sensor signal
16* Loss of battery voltage detected with engine running
17 Engine stays cold too long (bad thermostat)
21 Oxygen sensor signal out of range, possibly shorted
22* Coolant sensor signal out of range (or disconnected to set timing)
23 Intake air temperature signal out of range
24* Throttle position circuit out of range
25 Automatic Idle Speed (AIS) motor driver circuit shorted
or target idle not reached, vacuum leak found
26 Peak injector circuit voltage has not been reached
27 Logic module fuel circuit internal problem
OR
27 TBI injector does not respond properly to control signal
31 Evaporator Purge solenoid circuit open or shorted OR
Evaparator solenoid circuit
32 EGR system failure OR
Power loss lamp open or shorted
33 Air conditioning clutch relay circuit open or shorted
34 Speed control vacuum or vent solenoid circuits open or shorted
35 Cooling fan relay circuit open or shorted
36 Wastegate control circuit open or shorted
37 Shift indicator light failure, 5-speed (blown bulb) OR
Park/neutral switch failure
OR
37 Torque converter unlock circuit open or shorted, A-413 4-speed auto
41* Alternator field control circuit open or shorted
42 Automatic shutdown relay circuit open or shorted
42 Fuel pump relay control circuit
42 Fuel level unit - no change over miles
OR
42 Z1 voltage missing when autoshutdown circuit energized (whatever
that means)
43 Peak primary coil current not achieved with max dwell time
OR
43 Cylinder misfire
43 Problem in power module to logic module interface
44 No FJ2 voltage present at logic board
OR
44 Logic module self-diagnostics indicate problem
OR
44 Battery temperature out of range (see Note #1!)
45 Turbo boost limit exceeded (engine was shut down by logic module)
46* Battery voltage too high during charging or charging system
voltage too low
47 Battery voltage too low and alternator output too low
51 Oxygen sensor stuck at lean position
OR
51 Internal logic module fault ('84 turbo only)
52 Oxygen sensor stuck at rich position
OR
52 Internal logic module fault ('84 turbo only)
53 Logic module internal problem
54 No sync pickup signal during engine rotation (turbo only)
OR
54 Internal logic module fault ('84 turbo only)
55 End of codes
61 "Baro" sensor open or shorted
62 EMR mileage cannot be stored in EEPROM
62 PCM failure SRI mile not stored
63 Controller cannot write to EEPROM
64 Catalytic converter efficiency failure
65 Power steering switch failure
Copied from BC4x4.com
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
On my jeep the codes I got were 12, 33, and 55.
12 means you have recently unhooked your battery....mine had been unhooked till I tried the code thing.
33 means a problem with the A/C...this code will always pop up if you don't have A/C, which I don't
55 is the end of the codes...if all is well this is the only code you will get.
Just thought this was a cool thing....you other guys out there give this a try and tell me if it works on your YJ...I dunno about how the TJ system works...it may be different.
[addsig]
