2008 JK - Engine misfiring and security system issues
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JK Newbie
Joined: Dec 2020
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From: South Weymouth, MA
2008 JK - Engine misfiring and security system issues
My 2008 stock JK has had various electrical and misfiring issues this year that persist, brief timeline:
1. About six months ago, JK misfired persistently, I had an aftermarket coil installed and was fine for a bit.
2. Two weeks after above - entire car shut down, PCM completely unresponsive. Sent it out to get rebuilt (Car Computer Exchange in Raleigh, NC) and tech found the issue to be a cracked coil (the new one from above) that surged the PCM and killed it. PCM rebuilt, new aftermarket coil installed. Worked fine for months.
3. After six months, jeep misfired again and I got the same P2302 code (insufficient ionization - ignition coil). I also got unusual behavior with the security system (red indicator light blinking while driving and once the security system actually went off while driving). Sent it to the tech, they spent three weeks on it and sent it to another shop too, could find nothing conclusive. They swapped out spark plugs, ignition cables, fuel injectors, inspected wiring in ignition harness, etc. So they put in an OEM ignition coil under the theory that the PCM was picky with the aftermarket parts.
Within a week, I got a misfire, but it did not persist like before (cycling the engine cleared it) and got a P2302 stored code. The security system issues still recur intermittently (mostly the red indicator light coming on when driving). Called the tech, he said he's out of ideas and gave me money back for the coil.
Now I'm on a wild goose chase trying to figure out. Have a theory maybe the WCM shares wiring with the ignition so started there - I had the aftermarket remote starter that hasn't worked for years and bypass removed. After removal, still have the security issues (possibly the WCM is compromised, it was replaced about 10 years ago). The code I'm getting is B210A, which points to a sentry mismatch, and from my research is an intermittent lost handshake with the sentry key, otherwise car would not start. Tried different sentry keys, no change. But there may still be a link here, because while they were in the steering column to remove the remote starter and bypass, that I got the P2302 code again. No misfire this time, just a stored code. But what would the odds be that these two intermittent codes surfaced at the same time?
So my theory is either the WCM itself or some shared wiring between the ignition and the WCM to the TIPM is compromised (bad ground, compromised wire, etc) and is causing both issues. Does this theory have any weight and/or is there anything you would suggest exploring as a next step? Not so many techs are interested on working on an old Jeep with no clear root cause, so trying to figure what I could troubleshoot myself or point a tech toward.
Thanks for reading, appreciate any help you have.
1. About six months ago, JK misfired persistently, I had an aftermarket coil installed and was fine for a bit.
2. Two weeks after above - entire car shut down, PCM completely unresponsive. Sent it out to get rebuilt (Car Computer Exchange in Raleigh, NC) and tech found the issue to be a cracked coil (the new one from above) that surged the PCM and killed it. PCM rebuilt, new aftermarket coil installed. Worked fine for months.
3. After six months, jeep misfired again and I got the same P2302 code (insufficient ionization - ignition coil). I also got unusual behavior with the security system (red indicator light blinking while driving and once the security system actually went off while driving). Sent it to the tech, they spent three weeks on it and sent it to another shop too, could find nothing conclusive. They swapped out spark plugs, ignition cables, fuel injectors, inspected wiring in ignition harness, etc. So they put in an OEM ignition coil under the theory that the PCM was picky with the aftermarket parts.
Within a week, I got a misfire, but it did not persist like before (cycling the engine cleared it) and got a P2302 stored code. The security system issues still recur intermittently (mostly the red indicator light coming on when driving). Called the tech, he said he's out of ideas and gave me money back for the coil.
Now I'm on a wild goose chase trying to figure out. Have a theory maybe the WCM shares wiring with the ignition so started there - I had the aftermarket remote starter that hasn't worked for years and bypass removed. After removal, still have the security issues (possibly the WCM is compromised, it was replaced about 10 years ago). The code I'm getting is B210A, which points to a sentry mismatch, and from my research is an intermittent lost handshake with the sentry key, otherwise car would not start. Tried different sentry keys, no change. But there may still be a link here, because while they were in the steering column to remove the remote starter and bypass, that I got the P2302 code again. No misfire this time, just a stored code. But what would the odds be that these two intermittent codes surfaced at the same time?
So my theory is either the WCM itself or some shared wiring between the ignition and the WCM to the TIPM is compromised (bad ground, compromised wire, etc) and is causing both issues. Does this theory have any weight and/or is there anything you would suggest exploring as a next step? Not so many techs are interested on working on an old Jeep with no clear root cause, so trying to figure what I could troubleshoot myself or point a tech toward.
Thanks for reading, appreciate any help you have.