Multiple blown ignition coils on 08
#11
Couldn't find the coil in the pdf above, so here's a schematic (below). Note that the coil pack has 4 pins, switched B+, and the other 3 pins are for the PCM to intermittently sink (connect to neg ground) like ignition points did in an old-fashioned distributor. Have you checked for codes (e.g. P2305), if not that may provide info to troubleshoot with.
#12
JK Junkie
DTC's
Have you checked for codes (DTC's).
That's the first step, that's where every tech will begin with something like this.
That's the first step, that's where every tech will begin with something like this.
Last edited by Mr.T; 05-18-2023 at 01:11 AM.
#13
Yea it has a random misfire due to the melted pack, put a new pack in and no codes until she melts that pack then random misfire there is no code prior to the pack melting, but I can't be without a car anymore I gave up on her last night so it doesn't matter shop will figure it out I been on here for the past 3 months trying to sort this out, what waste of time
#14
Super Moderator
You need a shop that has Witech software which is the Jeep operating software. I keep repeating myself here saying this but the reason is with a million Jeeps out there aging these issues are going to come up in the 100's if not thousands with electronic problems especially if a Jeep is wheeled a lot in wet situations. I still maintain a lot of wiring issues are related to floating voltages caused by bad ground connections. How your coil issue relates I do not specifically know but the fact that you have replaced the part a few times tells us that the issue is high voltage or high current which causes the meltdowns. Have you gone out there on a pitch black night and opened the hood and observed the engine idling? Will see if there is insulation breakdown under high voltage. Old farmers troubleshooting trick.
#15
JK Junkie
One last thought: High underhood temperstures can make coils fail. If you have one of those grille things, or anything restricting air flow, that might be the problem.
#16
You need a shop that has Witech software which is the Jeep operating software. I keep repeating myself here saying this but the reason is with a million Jeeps out there aging these issues are going to come up in the 100's if not thousands with electronic problems especially if a Jeep is wheeled a lot in wet situations. I still maintain a lot of wiring issues are related to floating voltages caused by bad ground connections. How your coil issue relates I do not specifically know but the fact that you have replaced the part a few times tells us that the issue is high voltage or high current which causes the meltdowns. Have you gone out there on a pitch black night and opened the hood and observed the engine idling? Will see if there is insulation breakdown under high voltage. Old farmers troubleshooting trick.
#17
Shit I do have a us flag mesh insert thing, I'll take it out and try that maybe get some poison Spyder louvers
#18
JK Junkie
Definitely get rid of the grille insert -- They are terrible in warm climates!
#19
Pulled the grill cover off put it back together and cold started it and let it idle ran ok for 3 mins then idled funny and blew up another $70 coilpack, so it's not over heating from engine temp, engine isn't even into triple digits when it blew according to my temp laser..... I've never had a vehicle cause a problem I couldn't fix this is infuriating on top of paying $80 a day in Uber fees to get to work the damn jeep eats 70 bucks every time I start it now
#20
JK Junkie
Referring to the schematic I posted earlier, have you checked resistance to ground at the connector to the coil pack, on all 4 pins.
The 3 pins going back to the PCM should read the same (high) resistance. To be clear, not checking the coil, test the pins on the connector with wiring.
Edit: I'm expecting pin 4, wire K17, will show a low resistance to ground -- which would draw some amount of continuous current through coil #2. But it probably is, or was, an intermittent fault. And when it happens it miss-fires initially, then burns up the coil from too much continuous current. If this is correct (and that's a big if), it points to wiring (K17) that's grounding or a bad PCM. Disconnect C2 at the PCM to isolate the PCM from the wiring and re-check resistance.
The 3 pins going back to the PCM should read the same (high) resistance. To be clear, not checking the coil, test the pins on the connector with wiring.
Edit: I'm expecting pin 4, wire K17, will show a low resistance to ground -- which would draw some amount of continuous current through coil #2. But it probably is, or was, an intermittent fault. And when it happens it miss-fires initially, then burns up the coil from too much continuous current. If this is correct (and that's a big if), it points to wiring (K17) that's grounding or a bad PCM. Disconnect C2 at the PCM to isolate the PCM from the wiring and re-check resistance.
Last edited by Mr.T; 05-18-2023 at 12:56 PM.