hello,

I'm having an issue with 2001 xj. after the storm we had in the north east the other day i started the car up and the horn went off and wouldn't shut off. i had to disconnect the battery, find and pull the fuse and then continued to work. noticed it was idling rough and hesitating on acceleration. i scanned it a came up PO122 PO123 throttle position sensor codes. also airbag light is on. I'm looking for specific advice on what i should do next. i pulled the connector and cleaned the connection but nothing else so far.

thanks

 

Sounds like 2 unrelated issues; clock spring failure & TPS circuit.

 

If yours does what mine did to where it would idle rough to like 500 rpms and drop down and have to give itself gas and when I would drive it would hesitate and kind of bog down on the gas then get on it how ever much I pushed down on the gas, my check engine light is on and it happened after I went through very deep puddles and got some water in the exhaust, I'm pretty sure it's an o2 sensor, but if it's cold while it does and doesn't do it when it's warm it might be your egr sensor

 

egr sensor?

 

Exhaust gas resurculator

 

The '01 doesn't have an EGR system.

 

By chance, did you leave the windows down and hood open while it was storming..?

 

+ Horn = Clockspring.

Try removing the Horn Relay from the Junction Block and see if this clears the Horn, TPS, and Airbag light issues.

 

i wasnt thinking about that, apologies!

 

the codes say its a tps voltage issue. does sound like a faulty tps?

 

Follow CCKen's advice in post #8. He's sharp on this issue.

This is likely related to the clockspring as it shares some common circuitry with the TPS.

 

Could be, but with associated horn and airbag light it does point toward the clockspring being defective.

What happens is that near battery voltage from the horn relay control coil bleeds through the clockspring to the cruise control circuit, to the 5 volt reference circuit from the PCM, to the sensors that use it and cause the sensor(s) to go nuts. The defective clockspring would also cause the horn to sound and the Airbag circuit to be corrupted.

It depends on what fuse you pulled to kill the horn that would determine if it's necessary to pull the horn relay. If it was fuse 21 in the JB, that's the power contacts in the relay, if it was fuse 4 (50 amp) in the PDC, that's the power to the relay control coil and power to fuse 21 in the PDC other circuits.

You could check the 5 volt reference voltage at the TPS. It's the pin with the Orange wire. Measure from it to the engine as a ground. You should see approximately 5 volts with the ignition key to ON (RUN), without starting the engine. If the voltage is much higher than 5 volts I would suspect the clockspring. If the voltage is close to 5 volts, it could be a bad TPS.

 

ahh i thought it was odd that both issues came at the same time. during and after a rain storm. the fuse i pulled was 21

 

See if you can pull the horn relay and see if it fixes your problems. If it does, there's probably a clockspring in your future.

You can leave the relay out but you'll have to use your middle finger to signal your intentions.

Some States require a horn.

 

I pulled the relay as you suggested and it's much worse now. Idling very erratically and wanting to stall. Any clue?