Jeep won't pass smog as the check engine light won't turn on. Opened the dash replaced the bulb and even swapped other bulbs and won't turn on. Looked at the wiring harness for the right side of dash and it has some wires that are cut. Is this normal?
Dash wires cut, Jeep won't pass smog: Is this normal?
- Thread starter Jeff1999TJ
- Start date
John Scoggins
TJ Enthusiast
Might need to remove the instrument cluster, clean the two connections behind the instrument cluster and reinstall. That fixed several lights and the oil pressure "gauge" on mine a while back.
You can also have the IC run a self test, that will function all the lights and gauges, that might give an idea of the problem.
You can also have the IC run a self test, that will function all the lights and gauges, that might give an idea of the problem.
xxdabroxx
TJ Addict
Just bought the Jeep and had a code but got it fixed "small evap leak" No codes in the system but won't pass smog without the check engine liggt coming on then turning off when it starts .
John Scoggins
TJ Enthusiast
Need to know the year of your TJ to help you with wiring. Do everyone a favor and finish filling out your profile, makes it easier for folks to help
Edit: I just noticed your name, I'm assuming you have a '99 then.
Anyway here's a pinout of the connectors from my own '99 manual, looks like the suspect connector is C2. Note that the wires shouldn't be cut. I'd do some rooting around where the harness continues and see if you can't repair them. Your factory service manual is available in the "TJ Resources" forum, you can check out section 8W so see exactly where the cut wires go. If you need a hand interpreting the schematics let us know.
Edit: I just noticed your name, I'm assuming you have a '99 then.
Anyway here's a pinout of the connectors from my own '99 manual, looks like the suspect connector is C2. Note that the wires shouldn't be cut. I'd do some rooting around where the harness continues and see if you can't repair them. Your factory service manual is available in the "TJ Resources" forum, you can check out section 8W so see exactly where the cut wires go. If you need a hand interpreting the schematics let us know.
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Pulled all the wires out and both have cut wires. Followed the trail and don't see anything coming from the base of the wires.
John Scoggins
TJ Enthusiast
To me it looks like those connectors have been replaced and the wires that are not conneted may not have been used, I think that one set is for the rear window defroster.
Have you ru nthe Instrument Cluster Self test? If not then reinstall the cluster and run it. You can see if the engine light indicates or not, if it does not then there might be a problem with the IC circuit board itself
Have you ru nthe Instrument Cluster Self test? If not then reinstall the cluster and run it. You can see if the engine light indicates or not, if it does not then there might be a problem with the IC circuit board itself
John Scoggins
TJ Enthusiast
I looked at the wires vs the schematics on the diagram and not sure what "C1 cluster number one" CCD BUS(-) is for .
No errors just none of the lower right lights came on "check engine" "check Gages"
John Scoggins
TJ Enthusiast
You might have the color indication on the pin out backwards, the CCD BUS(-) shows to be a White wire with a Black stripe, which looks to be in connector C1 as does the Light Green with Orange Stripe and Orange on C2. It looks like the Rear Defroster is not connected.
Since you did not get a communication error with the PCM (it would have shown buS b0) you might have a transistor problem with the IC itself. Since both the Check Engine and Check Gauge lights are switched on by grounding the socket through a transistor located in the IC circuits that might be where the issue is.
IF you can remove the white cover on the back of the IC it will expose the circuit board, you might want to take a look to see if there are any burnt/corroded traces or spots on the board.
Since you did not get a communication error with the PCM (it would have shown buS b0) you might have a transistor problem with the IC itself. Since both the Check Engine and Check Gauge lights are switched on by grounding the socket through a transistor located in the IC circuits that might be where the issue is.
IF you can remove the white cover on the back of the IC it will expose the circuit board, you might want to take a look to see if there are any burnt/corroded traces or spots on the board.
I removed the back plate on the IC and None of the circuits or board show any issues. I followed the wires and found the ground on the left foot area that should be attached to the IC wiring harness is not attached and capped off. Can't find where to attach it. I'm 50/50 of I should order a new IC or the wiring harness for it.
John Scoggins
TJ Enthusiast
You followed the Black with Light Green wire from the connectors to that "dead end"? One way to make sure the IC ground is good it to check resistance or continuity between the Black and Light Green wire and the chassis. If it shows open then that might be the issue as both the Check Engine and Check Gauge lights as illuminated by being grounded VIA a transistor in the IC circuitry. If that ground is missing the light cannot illuminate.
IF the ground is good then it seems to be pointing to an IC issue, have the Check Engine and Check Gauge lights ever worked since you have owned it?
I would hate to spend ~100.00 bucks on an IC and that not be the problem. Do you know of someone that has a similar jeep you could swap IC's with to see if the light work?