Topic: Check engine light codes

[bootguy]

These are the codes in the order that the were displayed.  So I know the first 2 and the last one do not really mean anything but have left them in for reference.  Do they show in the order that they happen? So The Jeep runs and just has an intermittent miss, I am replacing the alternator to fix code 41.  So my biggest issue is code 37 & 11.  The question is whether the bad alternator can cause the other codes.

CODE 12   Battery or computer recently disconnected within the last 50 start cycles). This is a very common code. Will not trigger a "Check engine light".
CODE 33   Air conditioning clutch relay circuit open or shorted. If your Jeep doesn't have AC you will always get this code. Will not trigger a "Check engine light".
CODE 37   Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. Incorrect input state detected for the Park/Neutral switch. Auto only.
CODE 41   Alternator field control circuit open or shorted.
CODE 11   No crank reference signal detected during cranking. Timing belt skipped one or more teeth; or intermittent loss of either camshaft or crankshaft position sensor
 CODE 55   PCM has finished telling you the codes. This means you are done reading codes.

[chardrc]

I would check your grounds, connections to the battery along with the battery and alternator before jumping to replacing the alternator. I have had loose grounds and corroded battery terminals cause all kinds of odd warning lights and codes to happen on my WJ and JK (I know not the same as a YJ / tj but similar principles apply). I recently found that a dieing battery can cause the voltage regulator in newer ecus to cause an over voltage event in a near stall condition which makes it disable the charging system resulting in various sensors and systems throwing codes as the voltage continues to drop and finally a dead battery the next time you go to start the jeep  .

[bootguy]

New Battery, upgraded cables and cleaned all grounds when replacing the cables about 6 months ago.  The alternator is/was bad putting the replacement in today or tomorrow, thought about the Mean Green option but do not need it at this time.  I will see if that clears up the other codes.

[Jeffy]

New Battery, upgraded cables and cleaned all grounds when replacing the cables about 6 months ago.  The alternator is/was bad putting the replacement in today or tomorrow, thought about the Mean Green option but do not need it at this time.  I will see if that clears up the other codes.

I'd recommend at least putting in a 90a alternator instead of the stock 75a.  Cost should be the same.

[bootguy]

Did the 90amp today, instructions said 15 minutes.  3 hours later after replacing half the bolts and having to go into town for shorter serpentine belt it is all in and working.  No longer have the check engine light on, but when checking it is still throwing 37 and 11.  is this a holdover or still need to look for other things?

[bootguy]

I now have a new code, 25 what do I need to look for now?

12   Positive battery input to PCM was disconnected within the last 50 Key-on cycles.
33   An open or shorted condition detected in the duty cycle purge solenoid circuit. (A/C clutch relay circuit)
37   Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. Incorrect input state detected for the Park/Neutral switch. Auto only.
25   A shorted or open condition detected in one or more of the idle air control motor circuits. Actual idle speed does not equal target idle speed.
41   An open or shorted condition in the generator field control circuit.
55   Completion of fault code display on Check Engine lamp.

[bootguy]

Any idea of how to test #37 or #25?

[Jeffy]

#37 - Does your speedometer work?  Tach?  How accurate are they?

#25 - Take the sensor out and clean the piston. Re-seat the connector.  Does the engine have a hard time starting up?

[bootguy]

Speedo and tach work and are pretty accurate as I had everything calibrated about a year ago when I put 31's on.

Went to pull the sensor today and clean everything, have to do a little more in depth cleaning than anticipated.

[bootguy]

Lots of little problems that had to be fixed, replaced intake and exhaust manifold. cleaned quite a few electrical connections and this seems to have cured most issues and lights.  got it on the road for a whole week and the distributor came apart.  Replaced it and started right up with zero issues.  Went to go out this morning Nothing, I mean absolutely nothing.  Time to start from scratch and throw more money at the thing.

[Jeffy]

That's the problem of driving a Jeep that hasn't been daily'ed in awhile.  Once you get it up and running it should be reliable.