Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: Shearcon79 on July 06, 2008, 02:11:55 PM
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My YJ 4.0L has a few issues. First of all it comes up with these codes...
#12 - Direct battery input to PCM was disconnected within the last 50 key-on cycles
#24 - Throttle position sensor input above maximum acceptable voltage.
or
Throttle position sensor input below minimum acceptable voltage.
#33 - An open or shorted condition detected in the A/C clutch relay circuit.
#51 - Oxygen sensor signal input indicates lean air/fuel ratio condition during engine operation.
So #12 is pretty obvious.
#24 - should I just replace the sensor or is there something else wrong.
#33 - I don't have A/C
#51 - Does this mean the sensor is pooched or is the code for some other reason?
A little history... These same codes have been coming up for a while. I had a cracked header and when I was driving it the engine would cut out during acceleration or while climbing a hill...but only for a second then it would run fine again. I decided to swap the header for one that I found at Pick n pull. In the process I dismantled the intake ie. sensors,throttle body,vacuum lines and cleaned everthing. It was pretty dirty.
When I re-assembled everything and started the jeep up the check engine light came on right away. Also it runs very rough. almost like it wants to shut off but doesn't...low idle RPM. When I drive it really sputters badly.
Any thoughts?
PS. It sounds better with the new header!!! whoohooo! ;D
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#12 will go away after a while, just need more than 50 key cycles, I believe you can test the TPS sensor with either a voltmeter or Partsource can do it (not too sure).
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every few years i have to change the TPS. id change it and see what happens.
#33 is an odd one if you dont have a/c. did it ever have a/c? it could have been removed. or has the pcm ever been changed?
if your O2 sensor reads lean, its probably cause theres too much air in the exhaust, or not enough fuel. usually when i pull an O2 code the last thing i do is change the O2 sensor. look for a vacuum leak. or even a cracked exhaust manifold. i know you changed yours out, but its a common problem on the older 4.0L engines to have cracked exhaust manifolds. in the end, changing over your old O2 could have caused it some harm, but look at the other possibilites first, then go to the o2.
good luck eh;)
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The code 33 will never go away , nor is it a concern .
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Thanks guys for your input. I will check the sensors and look for leakage in my manifold. If I disconnect the battery does that clear the codes except for #12? or do I need the code reading module?