multiple issues

Hey guys I bought a 2000 cherokee 4x4 Auto about a month ago. It has 177,000 miles. When I first got it I noticed that it had a high idle of around 1400 in park. The fuel gauge was also not working. So I checked all the fuses first and found the f22 fuse blown in the PDC. I believe that this is for the fuel pump, although it was running with it blown. Next I cleaned the IAC with no luck, so I bought a new MOPAR IAC. When I installed it the idle would stay around 2000 rpm until I touched the throttle and it would jump up to around 3000 rpm. Every once in a while I get the no bus message and it doesnt shift right, but if I let it sit a few minutes the no bus goes away and it shifts normal. I took the new IAC and plugged it into the connector ( it wasnt mounted ) to see if it would move and it does nothing like it is dead. Do you guys think that I have an electrical problem that is causing all of this or do you think it is all unrelated? I have been messing with for a month now and it is driving me crazy. It runs great other than these things and the check engine light on at all times. Thanks for any responses.

First thing is to pull the failure codes out of the computer. Check engine light means there is a failure code. Some part stores do it for free.

Yes it showed a p0505, p1694 no CCD messages recieved from ECM. and p0123. Sorry I forgot to post those in the OP.

So I took it to advance auto this afternoon and they did a load test on the battery and also checked the alternator. Well both of them failed so I got a new battery and the alternator will be here tomorrow. I did try to put the New IAC back on after replacing the battery and the idle is still up around 2000rpm's. I hope when I get the alternator put on tomorrow it will solve this check engine light/high idle ordeal.

Ok so advance auto checked the battery and alternator both were bad, so I changed them both out. Still have the extremely high idle. I did notice in the morning when the jeep is cold it only idles about 1100 then when it warms up it goes to 2000, and if I touch the throttle it shoots to 3000. I pulled the harness apart and found no bad wires I also cleaned all grounds. I am out of ideas. Does anyone think that the PCM is bad causing this? Is there a way to check the PCM? Thanks

My Renix high idle was caused by vac leak and a loose manifold bolt

Would'nt a vacuum leak cause a high idle whether the engine was cold or hot?

hot1le said:

Would'nt a vacuum leak cause a high idle whether the engine was cold or hot?

Click to expand...

Honestly - I don't know. Unfortunately, I come here with more questions than answers

I do know that the high idle from manifold leak can come and go with engine temp - based on my experience.

I trouble shot it with a can of starter fluid, was able to pin point the leaks.

Did you have a check engine light when you had the manifold leak?

No CEL in 1988

Just wanted to give everyone an update. It was the PCM, as a matter of fact when I replaced the PCM my Gas also started to work. Go figure, guess I should have replaced that first since thats what I thought it was in the first place, but everyone said no way its the PCM, even the guy that sold it to me.LOL