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sprinkles08
sprinkles08, ASE Certified Technician
Category: Jeep
Satisfied Customers: 22363
Experience:  Chrysler/Dodge/Jeep Master Certified, ASE Master and Advanced Certified, Trans and Hybrid Specialist
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Grand Cherokee: I recently replaced the TPS sensor on my 2001

Customer Question

I recently replaced the TPS sensor on my 2001 jeep grand cherokee after the check engine light came on and gave that particular code. Replacing the TPS fixed the problem for about a day or two. Then I went to start the jeep and it wouldn't start right away (it eventually did) and I noticed that my clock on the dash had reset to 12:00. There was one other episode in which I got into the jeep (after already resetting the clock the last time) and it once again had reset to 12:00. Now my jeep will not run unless the gas peddle is pushed. It will start but will not idle. I am at a loss and not sure what to do. Battery? Faulty TPS?
Submitted: 1 year ago.
Category: Jeep
Expert:  sprinkles08 replied 1 year ago.

Hello and welcome to JustAnswer!

The starting/idle issue is likely related to the clock resetting. The clock is resetting either because the radio is losing power or voltage is falling low enough while cranking that it's losing memory.

The starting/idle issue is being caused by the idle air control motor not opening far enough to support the engine's needs. This can be the IAC itself, a wiring issue or failed driver in the powertrain control module, but if battery voltage is lost or goes low enough then the PCM's IAC step count will be lost and it will have to be relearned, until then it won't idle correctly.

Make sure the battery connections are clean and tight. If ok, turn the headlamps on and wiggle test the connections at the back of the terminals to make sure there isn't an issue between one of the cables and terminals. If ok then I would recommend having the battery load tested.

Customer: replied 1 year ago.
Could the voltage issue of voltage be related to the throttle position sensor?
Expert:  sprinkles08 replied 1 year ago.
The TPS won't cause the issues you're having.
Customer: replied 1 year ago.

When you say "This can be the IAC itself, a wiring issue or failed driver in the powertrain control module, but if battery voltage is lost or goes low enough then the PCM's IAC step count will be lost and it will have to be relearned, until then it won't idle correctly." what do you mean by a wiring issue? Also how would the PCM's IAC step count become "relearned"? By driving it?

Also when you say " If the battery voltage is lost or goes low enough..." I assume you mean because the battery is bad? I cleaned the IAC sensor and Throttle body. Battery volts read over 14 volts, so it should be good but I don't know how to load test the battery. Can I take that to a place like autozone to have it tested?

Read more: http://www.justanswer.com/jeep/94wlo-grand-cherokee-recently-replaced-tps-sensor-2001.html#ixzz3cceu2qTD

Expert:  sprinkles08 replied 1 year ago.
If any of the four IAC driver wires was open, shorted to power, ground or another circuit it would prevent the IAC from being properly controlled.
The IAC step count can be reset with a scan tool or through driving
Battery voltage to the vehicle could be falling low enough because the battery is bad or there is a cable or connection issue.
Autozone and most other big chain parts stores will load test batteries for free.
Customer: replied 1 year ago.
The jeep started and has been running fine for a few days. Yesterday morning I went to start it and I got nothing, no lights, power, gauges,etc. when I take the key OUT of the ignition there is a rapid clicking noise and the interior dome lights in the front began flickering very dimly. The clicking has now lasted about 12 hours with the key OUT of the ignition and is still clicking. When I put the key in the ignition and turn it slightly to the "ON" position the clicking stops but the guage needles start jumping all around...still with zero power, lights, etc. I am at a loss here. Supposedly the battery checks out ok, even load tested. I have not tried to jump the battery as I am debating whether to leave it as is for a mechanic to take a look at to see what is going on currently.
Expert:  sprinkles08 replied 1 year ago.
Either the battery is dead or there is a cable/connection issue preventing voltage from making it from the battery to the vehicle.
Customer: replied 1 year ago.
So a dead battery is causing it to click all night long? How can the battery be dead if it tests ok? Could there be something draining the battery? What cable/connections specifically should I be checking other than battery terminals? Would you recommend I try to jump start the jeep? Should I test the battery before I jump it if so?
Expert:  sprinkles08 replied 1 year ago.
Yes, a dead battery can cause the click or the clicking may be related to an issue that's causing a battery draw.
The battery terminals, cables and connections, chassis and engine ground, and power distribution center cables and connections are all possibilities.
If the battery tests ok it isn't dead, but I'm questioning how and when it was tested. If it wasn't load tested on a machine today after this problem started you don't know it's condition. You can try a jump start if you haven't already.
Customer: replied 1 year ago.
I was able to jump start the jeep. The battery (positive) was extremely hot to touch. Because it was clicking all night? Drove it about half a mile to my parents garage and it stalled out. Assuming the battery did not fully charge. My gauge reads 14volts. Popped the good and something around the battery was smoking. What would that be? My plan is to charge the battery overnight then get it to advance auto to have the battery and alternator both tested. Any idea on the smoke?
Expert:  sprinkles08 replied 1 year ago.
I wouldn't recommend charging the battery. I would recommend disconnecting it and then having it load tested. It may have an internal issue that would make it unsafe to charge. The smoke could have been from the battery itself or a wiring/connection issue. If the positive terminal was hot it could have been because of the battery itself or a poor connection at the terminal or between the terminal and cable.