Limp mode??

[sirfranky]

I did alot of searching before I decided to make a post. It seems these Intrepids go into limp mode alot, but for varying reasons. I ran a test on mine due to the non shifting transmission and engine check light on. I was lucky to get a printout of the trouble however I do not know what this is.... ( The onboard computer controls the engine idle using a stepper motor. The motor controls a valve to adjust the idle. The compuiter will adjust the stepper motor until the RPM's are a t the desired engine idle. If the stepper motor fails or the onboard computer cannot adjust the idle enough to reach the desired RPM's a trouble code will be recorded.) So I guess I need a new stepper motor... What is a stepper motor? And where is it at?

[sirfranky]

I called the dealer the trans shop and then the parts store they list the stepper motor as an idle air control motor for $40.00. The next step is to determine where it might go.........

[neon_rt]

I think you may be in over your head.
Limp mode is to preserve the transmission and it takes a special reader to get the codes from the transmission controller.
You may have an idle problem but that shoudn't cause "limp mode" to activate.
I would suspect that you could have another problem that is causing the idle speed motor to have problems and the transmission to have problems at the same time. I would have the whole thing checked out. It could be that the Throttle Position Sensor is bad and or the throttle body is dirty. If the throttle position can not be properly determined the trans controller would be confused as to why the trans is behaving as it is given the throttle position. Don't start spending money curing symptoms when you don't know the problem. The 2 issues may not be related, then again...
I hope you realize that Treps need a lot of extra care to be reliable. Regular tune-ups (complete with Throttle body,combustion cleaner and injection cleaner), Synthetic Oil only (to prevent chronic sludge problems and timing chain failure) , Transmission fluid and filter change every 30-50K miles (Mopar ATF+4 fluid only), coolant changes (most people change back to green coolant, as there seems to be corrosion problems with the orange coolant, corrodes the head gaskets out). I know people with 150K trouble free miles that follow these guidlines. I know people with 60K miles that need a new engine/transmission because they don't beleive what we say on the Forums.

[sirfranky]

Thanks that's the advice I needed. I hate wasting time and money.Is there any work I can do before the shop. I got access to a a 24 valve intrepid engine and trans the moter has blown heads but the tranny runs excellent is it true that they use the same tranny? I figure if the tranny is shot I can use it who knows.

[dksob81]

Originally Posted by sirfranky

Thanks that's the advice I needed. I hate wasting time and money.Is there any work I can do before the shop. I got access to a a 24 valve intrepid engine and trans the moter has blown heads but the tranny runs excellent is it true that they use the same tranny? I figure if the tranny is shot I can use it who knows.

Well the IAC Valve should be located on the Throttle Body. Neon is right about the IAC not causing the tranny to go into 'LIMP MODE'. I just fixed my boss' wifes car yesterday her car was going into limp mode, When you first start it and drive it would shift hard then when you slow down it would downshift then would not upshift again until you shut the engine off and restarted it. Hooked the computer up and gave us a few codes, went ahead and replaced the Input Speed Sensor, on the driverside fo the engine (front sensor) and she shifts fine now. The codes were P0700 (tranny malfunction indicator), P0733 (something about 3rd gear ratio), and P1790 (forget what this one was).

Neon_rt - you don't need a special chrysler scanner to read Tranny Codes, your generic OBD II scan tool for engine codes won't read them, but any monitoring took will read the codes, we have a snap-on fast track 2 graphic monitor at work in which we read the codes. But diagnosising the tranny is difficult with this one, the Chrysler DRB II (Digital Readout Box) scan tool is the best one for this along with diagnosising any Mopar problem.

[sirfranky]

I have an obd-II scan tool. Will I be able to pull any trouble codes from the trans with this and if not is it inexpensive to grab another scan tool and which one???

[dksob81]

Originally Posted by sirfranky

I have an obd-II scan tool. Will I be able to pull any trouble codes from the trans with this and if not is it inexpensive to grab another scan tool and which one???

Well you might be able to if the check engine light comes on. And yes it is expensive for the monitoring tool, ours was about $2600.