This can be from a variety of things...
Ran a Code scanner tool in the DTC connector to review or even check for pending DTC's?
Oil Level ok?
Coolant bottle ok? Color clear and clean or dark n dirty - oily?
Do this...
While getting into your car, locate the left side OK and menu arrow buttons on the steering wheel - You can hold the Left side OK button on the steering wheel and enter into "TEST" mode and using the OK Up and Down buttons can scroll thru various test "stages" including "Voltage Test" and see if the voltage from the battery is holding up.
To do that, you Press and HOLD left side OK down (in or whatever) and insert key turn it to Ignition (On) - don't start it yet. Hold the OK in until your menu displays "TEST" - then you can let it go - release it - and let it perform a boot into self test mode - then use the Up or Down arrow on the Left Side OK - and you'll see it scrolls thru various stages or test results - you can also start the car at this time - but scroll to find "Battery Voltage" first - and look at those results - then start the car and see if the voltage can rise fast enough - if it's slow to rise, then you may have to get down and dirty and start cleaning grounding points - they may be corroded or as I have found - several wires in a bundle sent to ground - have broken away or literally have had the copper in the wire corroded away from the lug holding it to the grounding bolt.
Then you have to strip the wire and resolder it back onto the harness lug so it can make ground again.
That is if you have such a means, if not, then you'll have to use a DVM (Multi-tester) and run a "battery monitor" test (check voltage) using the DVM and even do resistance checks from the Throttle Body connector to ground - find the lowest ohmic reading value one, the one that Grounds (provides Return) for the Throttle body, it's supposed to be less than one ohm - measured to the battery or frame ground - it could be that the grounding point wire, in any bundle from the harness that grounds at various locations - has failed and is why you're seeing such a high idle because it can't "see" any true voltage reference across itself to "zero" the electronics so it knows where the throttle is set.
I have an identical problem with my '01 2.0, are the steps the same to diagnose?
No codes as I had just put the battery in.
Oil Level is fine.
My coolant bottle is dirty, but has been that way for probably the last 80k miles (212k on the vehicle)
I have a Bluetooth scanner that I can read all the sensors with, the voltages read as soon as I plug it in/start it. I did notice when I unplug my tps, there is no change on how the engine is running though.
The car ran fine until I replaced the starter, in doing so I pulled the intake manifold, and then had to replace the throttle body after cracking the original when trying to remove it.
I have checked in every possible way for vacuum leaks, but with the RPMs up this high, it would have to be a huge frigging leak, and I'm not finding anything using starting fluid.
Unlike his car, my RPM's do not creep back down.
This is not an attempt to hijack his thread either, but it didn't make any sense to me to start a new one with a identical issue.
