My 87 Sundance had a Code 24 issue for a short time. It would go into limp-in and if I stopped and turned the car off and on it would sometimes go away. Sometimes while driving down the road it would come back and the car would go into limp-in mode where the computer would ignore any input from the TPS and extrapolate throttle position based on the MAP sensor readings.
I cleaned the connector on the TPS, the Logic Module and the various grounds and all was better again. BTW, Barry's right, there is no Throttle body temperature sensor. There is a Intake Charge Temperature Sensor and there is even a battery temperature sensor. The CTS measure the temperature of the intake "charge" and is pretty important on turbocars since they tend to heat up the charge quite a bit. On early t1 cars, the throttle is a drawthrough only and won't see the intake charge temps the rest of the intake system does and so a TBTS wouldn't get you much except ambient air temp (which can be useful, but that's another discussion) On the later cars where the throttle body is part of the intake tract then it might be possible to do, but the wiring was already in place for the intake mounted CTS. Best Regards, Stefan Mullikin Portland, OR Co-Founder PNW-SDAC http://www.pnw-sdac.org 1980 Fiat X-1/9 1984 Dodge Rampage 2.2 1987 Plymouth Sundance Turbo 1987 Shelby CSX #106 1988 Shelby CSX-T #3 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Marshall Montchalin Sent: Tuesday, October 11, 2005 7:17 AM To: Barry Goodall; shelby-dodge@imagicomm.com Cc: [EMAIL PROTECTED] Subject: Re: SD> 1987 Throttle Position Sensor Hi Barry, I apologise for taking so long to reply, but I was taken aback by your statement about there not existing any TBTS ! Please go to allpar.com to read Bohdan Bodnar's reply to someone who had a fast idle. There is in truth such a thing as a TBTS. Bohdan Bodnar's advice about cleaning the connector to the TBTS is right on and has solved the CHECK_ENGINE light on my car after the third unplugging&spraying with tuner cleaner as he advised. Kudos. Try http://www.allpar.com/fix/AISmotor.html and look for Bohdan's truth there. Other good places are Donovan's Dodge Garage and Russ Knize's Minimopar pages. I am not going to build a RESET for my car's computer mind because after that last spraying of the CTS, or TBTS(they're the same thing) connector, the gradually speeding idle has not returned: neither have I felt the need to RESET the computer again. I don't understand the limp-in mode for code 24: my car sets this code, turns on the light, and enters limp-in. What if I shut off the engine and restart it and the code doesn't light up? Am I in limp-in mode? I don't think so. That's the reason for wanting the RESET key inside the cabin. If it remains in limp-in, there would be no use for the RESET! This is low-priority now Thanks to Bohdan. What I know about code 33 is quoted from the Codes listed in the Mini-Mopar page: See code 25. Fault Code 25 will lead you to a code 33, but I have gotten a 25 too due to a bad ground or confused computermind. My car is only getting 22 mpg. with AIS unplugged and 5-spd. I have removed most of the plastic shrouding that leads from the carburetor to the driver's side, leaving only the air cleaner. Will try to get a picture. Ideas? Thanks, Marshall Barry Goodall <[EMAIL PROTECTED]> wrote: Hi Marshall, There are a few inaccuracies in what you have posted, so let's start with clearing those up. First off, there is no temperature sensor on the throttle body (no such thing as a TPTS), only a Throttle Position Sensor (TPS) and the AIS motor referred to by some folks as an IAC. > I want to clarify that my car has been running well for awhile now, > but that it occasionally sets the CE- Check Engine light while > driving. My car's limp-in mode is good, is there any way to get my CE > code while in motion without shutting off the engine because some > codes are not fatal codes, just advisory? For the discussion here, any code you are getting that causes the computer to go into limp-in mode will remain after the car is shut off. I am pretty sure this is a hard & fast rule, but I will check each code you list to tell you diffferent if my documentation states so. The documentation I am using is the instructors guide that was used by the Chrysler training centers to train the dealer techs. > CE 15 is the speed/distance sensor, and once set it goes back to > normal because I can set the cruise control. My 5-speed has cruise > control, and its great for highways. The cruise control will only fail completely when the Speed/Distance sensor quits completely. The sensor may have a marginal fault that will cause occasional symptoms (for example, high idle when coasting to a stop) long before it goes bad completely. Fault Code 15 will not set limp in or turn on check engine lamp. > CE 24 is the TPS and the limp-in mode is to use the MAP sensor which > feels the throttle position according to the vacuum and acts > accordingly. This code will set the limp in status and the fault code will be stored in the logic module memory until the problem is fixed and the key is then cycled off then on again. The logic module monitors the signal line from the sensor many times a second. If it sees a value below .16v or above 4.7 volts it will set fault code 24. So if you are getting code 24, then the voltage the computer is seeing is outside of these limits at some point while the key is turned on. > For me, this is usually set by the ground in the TBTS plug beside of > the AIS that has been permanently unplugged, by decision of the > driver(me). > > I always get code 33, which doesn't mean "the AC I don't have" but > rather that the AIS isn't responding as expected instead of saving gas > as it does unplugged. I can live with a CE 33. Sorry, but you have been misinformed on this. Code 33 is indeed a sensed open in the A/C cutout relay. Any car not equipped with A/C will always have this code set and it should be disregarded. But all the code means is that the logic module did not see a change of state when it checked the relay (usually when the ignition is first turned on and the computer does it's diagnostic checks). Code 25 is for the AIS motor, but it only detects problems with the AIS control inside the logic module. Having the AIS motor unplugged will not set a code. From the instructors guide "An open circuit in the harness or AIS motor will not set code 25." and "So an open outside the logic module is not detected." > Maybe if I could hook up to the RS-232 diagnostic connection under the > hood, if I knew the Chrysler pinout to what should be an industry > standard serial bus, with a simple PIC computer circuit that would > read and display CE codes as they develop, on an LED display inside > the cabin? Might be easier to buy or borrow a DRB or scan tool from someone local to you. They will work while you are driving and allow you to view virtually all the monitored engine parameters. > Or if there were a reset for the computer that would tell it to check > again, and to go back to closed loop. My limp-in gets about 14 mpg or > less, compared to the aging motor's typical 22 mpg. Fixing the problem is really the best solution. > I think Russ Knize is right on about the grounds, and I wonder if I > could simply run silver wire from ground to ground around the car and > bring everything into good performance? > I will try that after I try adding ground wires in extra abundance to > these critical points on the fuel rail. I think I can get more grounds > from our local u-pull-it. Good grounding is a key to making these cars run right. Having all the factory grounds in place and making sure they are free of corrosion is really all that is needed. Best of luck with your efforts, keep us posted. Barry Goodall Shelby Dodge Auto Club '88 Plymouth Sundance 2.2l Used-to-drive: Chrysler Simca 1204 -----------------------REMOVE-FOOTER-WHEN-REPLYING---------------------------- Questions? Visit http://www.sdml.org/ To be removed, visit http://www.sdml.org/pages/leave.html
