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A friend of mine a has a 2005 crown vic that has a weird problem when driving at highway speed. anywhere from about 45-65 mph the car will occasionally hesitate for a split second, almost like hard misfire. He called me this morning saying that an orange wrench popped on on his dash and he said the car had a hard time going any faster than about 20 mph. he shut the car off and restarted it, the light was off and was able to drive again. This tells me the car was in limp mode. i did a little research and found that most of the time when the car acts like that with the wrench light on, it points to a throttle control motor (on crown vics). I’d like to test it but I’m not sure how. I’ve never had experience with drive by wire systems. I haven’t scanned it yet, i plan to tomorrow. any advice on testing these is appreciated.
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i pulled 2 codes off of it (both pending codes, none stored or permanent)
P061B- Internal Control Module Torque calculation performance
P2106- Throttle actuator control system-forced limited powerIm thinking the second code is just saying the car was put in limp mode but im not 100% on that.
I recorded 30 min of live data and graphs. I couldn’t get the car to act like it did before but i saw a few things on the graphs that i have wonders about.
I graphed 9 PIDs and had all available PIDs recorded as live data feed. ill post attachments of some of the spots that had me concerned. If theres any specific PIDs that you guys would want to see, ill take more screen shots and post them.
The 3 PIDs i graphed in these shots are commanded throttle actuator control(the top red graph), Absolute throttle position 1(the bottom red graph), and Absolute throttle position 2(the green graph).
i noticed that throttle position 1 and throttle position 2 values never match up. Not sure if its supposed to be that way or not but i would think they would be close together.
The first one is under hard acceleration. The TPS tops out then drops for a split second and pops back up. The tranny shifted around this point and im not sure if that would cause the dropped reading or not. I have the white line positioned at the drop point.
The second one is the same thing but at a different time. I dont remember if the tranny shifted during this point or not.
the third one is getting on it then letting off for just a second. The first peaks dont match up (throttle position 1 doesnt peak with the other PIDs) but the second ones do.
like i said, i can post more screen shots if theres any specific PIDs that you guys would want to see.
I will have to look into that stuff. im going to have to wait until the weekend to look into it. i know he just put a new filter in so maybe that’s whats causing the issue. I’ll try cleaning the throttle body while im at it and see what happens. Im thinking about doing a TPS sweep when i clean the throttle body an see if there’s any dead spots. thanks for the reply.
[quote=”sam_priem” post=86616]I will have to look into that stuff. im going to have to wait until the weekend to look into it. i know he just put a new filter in so maybe that’s whats causing the issue. I’ll try cleaning the throttle body while im at it and see what happens. Im thinking about doing a TPS sweep when i clean the throttle body an see if there’s any dead spots. thanks for the reply.[/quote]
You got it. Keep us posted on your progress. 🙂
Finally got a chance to look into it yesterday. The top of the air box was not quite sitting on the bottom properly but was still sealed against the rubber on the air filter. I fixed that, checked all clamps in the intake tubes, and cleaned the inside of the throttle body. I did do a TPS sweep with my fluke 88 (it has an analog pointer that works great for checking variable resistors). i noticed it had 4 pins instead of 3, which i wasnt used to, i normally see 3 pins. The sensor has 2 signal pins on it, reference voltage, and reference return (ground). i tested it with one probe on the reference voltage and another probe on one of the signal pins ( i tested both one at a time). im pretty sure that’s how its supposed to be done, but if im wrong, correct me and i’ll test it again. I found 1 spot towards the higher end of throttle percentage that dropped out but i want to make sure that ive done all the testing i possibly can before i throw a new sensor in it (a new one is about $150). I’ll give it a few more days to see if it still acts up and post another update.
If it’s a DBW system, be careful, especially cleaning the throttle. This can sometimes really mess up the reference for the computer and you have to reset it. By the sound of it, that’s not a problem in your case.
As for the readings you got, I don’t know if I’m convinced. If a TPS is bad, it often shows up as a drop out in resistance or voltage at a certain point and it’s consistent. If you’re not seeing that in a consistent spot, then it might not be an issue.
It’s hard to say if the problem is due to a throttle position issue or an issue with the transmission. Initially reading your post I was thinking of a transmission problem. That said, transmission problems can be caused by faulty inputs such as bad TPS readings.
This is a though one if I’m honest. I suppose the real question is this problem caused by a throttle reading being incorrect, or a transmission problem putting things into limp in mode.
The articles College man posted seem like a good start to me. Since you’ve already fixed the air box, perhaps it’s time to try a TPS according to the article. You might even need to take it in to see if it needs to be reflashed if the article applies to your situation.
Keep us posted.
As of now the problem hasn’t come back. not exactly sure which attempted solution solved the problem but so far its running fine. if it happens again, i may try putting a new TPS in it. I’m hoping its not a tranny starting to go. If it keeps happening, i’ll just have to tell him to take it somewhere where they have the ability to check into it more than i can and if needed, re-flash the pcm. As for cleaning the throttle, i disconnected the battery before doing anything. Not sure if that would help keep from screwing up the computer reference but i figured it cant hurt to disconnect it anyway. Thanks again for the replies, i’ll post another update in about a week or so.
[quote=”sam_priem” post=87912]As of now the problem hasn’t come back. not exactly sure which attempted solution solved the problem but so far its running fine. if it happens again, i may try putting a new TPS in it. I’m hoping its not a tranny starting to go. If it keeps happening, i’ll just have to tell him to take it somewhere where they have the ability to check into it more than i can and if needed, re-flash the pcm. As for cleaning the throttle, i disconnected the battery before doing anything. Not sure if that would help keep from screwing up the computer reference but i figured it cant hurt to disconnect it anyway. Thanks again for the replies, i’ll post another update in about a week or so.[/quote]
Glad its been good.keep us posted. 😉
update #2
Once again so far, so good. he hasn’t had anymore issues. I scanned it again to see if there were codes of any type and nothing showed up. Unfortunately, i cant say what actually caused the problem. It must have been one of the solutions i tried earlier, but i wouldn’t know which one. if any problems show up later i’ll post another update but i think as of now, I’m going to call this one solved. I appreciate all the help and links to get this figured out. thanks again.
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