97 Cher Sport Check Eng Light Code 12

97 Cherokee Sport 170K auto 4wd

Keep getting a CEL code 12 (battery disconnected) error. Then it will go away for a day, but it keeps coming back. 12 55.

Also, some times the auto trans will not shift into 4th gear. Presuming the throttle position sensor here, but why no error on that? That symptom goes away after restarting.

Only other flaky thing is the neutral safety switch. Always starts in neutral, but not alw3ays in Park.

ANy ideas?

Reply to
Rich D
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Sounds like an open ground circuit to me. I've seen this happen on big trucks; symptoms included PCM errors, intermittant starter failure, dim lighting, sensor-to-ground failures, stuff like that. Check the integrity of your negative battery cable, specifically where it bolts to the frame and engine block.

Reply to
Outatime

throttle position sensor here, but why no error on

Something is confusing the computer and putting things in limp mode.

The NSS is high on the transmission and a real bugger to get at. It might need replacement or the harness might have been damaged somehow.

Always. ^_^

Check your battery terminals and cables, they may be loose or corroded. I've even seen loose battery terminals.

check the engine ground strap and examine all the wire looms and runs for any snags or melts.

Assuming you have the I6, check the O2 sensor wire where it runs along the oil pan and is held to the block with a clamp. If the shield has melted it can short out and cause all sorts of problems.

Reply to
DougW

You (the group) might be on to something. The negative pole was fine - clean and dry, but the poisitve pole, while looking clean, when I took it off was moist. Probably wicked up from one of those anti-corrosive pads insatlled with the battery 2 years ago.

So far (12 hours) the CEL is off.

Reply to
Rich D

Spoke too soon. The CEL is back on with a Code 45 now attached. Can't even find a ref for that. Going to go get the OBDi checked for the real codes.

Reply to
Rich D

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