HELP!!! CAR BUCKING & PULLED CODES

cjhenry01

New Member
Mar 21, 2004
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First off I would like to state that I'm a complete newbie at this & that I need extremely detailed information/instructions.
I just purchased this GT w/ all of it's mod's last week and while I was driving it home I noticed that it likes to buck/hesitate at cruising speeds. This only happens between 1,500-1,700 rpm's at light throttle. It idles good & at WOT it runs perfect.
Someone please help me as this is so annoying to drive. I have to be able to cruise in my hometown or else this car is worthless.
I just pulled the codes and this is what I came up with.
Code #15
Code #23
I read somewhere that Code #15 is due to having a Chip. Is this true?
Thanks much!!!
 
Code 15 - No Keep Alive Memory power to PCM pin 1 or bad PCM (Memory Test Failure). The voltage to the Keep Alive Memory (KAM) is missing (wiring problem) or the KAM is bad. The KAM holds all of the settings that the computer "learns" as it operates and all the stored error codes that are generated as a result of something malfunctioning while the engine is running. Use a voltmeter to check the voltage to the pin 1 on the computer - you should always have 12 volts. No constant 12 volts = bad wiring. If you do always have the 12 volts, then the KAM is bad and the computer is faulty.

Code 23 - Throttle sensor out of range or throttle set too high - TPS needs to be reset to below .99 volts at idle. Keep in mind that when you turn the idle screw to set the idle speed, you change the TPS setting.

Here’s a TPS tip I got from NoGo50…

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better. Just don’t go over .99, or you’ll upset the fuel calibration and idle quality may suffer, along with some other problems like poor gas mileage.


(copied from MustangMax, Glendale AZ)

1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.
 
That code 23 might also be due to your MAF sensor being dirty. Pull your MAF and use a Q-tip with some carb cleaner and gently clean the two wires hanging down inside the MAF. Made a world of difference for me.