Car entering limp mode

[dptmachine]

I have been dealing with a gremlin. I got my car back from the shop and on my second drive, just a few miles from home, the car went into what I would call "limp mode". No response to throttle but would idle just fine. The DSC audio indicator and light went on. "I presume the audio beep was paired with the light". No engine lights. I drove it back home in second gear at idle.

Check a few resources online suggesting bad fuel, low voltage, transport mode, and then finally shut-off and restart to reset.

Went out next day, started right up-up no indicators and drove 15-20 miles.
I plugged in my OBDlinx mx blue tooth; no faults listed from memory? Voltage normal

Going out for another drive, OBDlinx left in, and went into limp mode. I shut it off in the middle of back country road, restarted and off again. 400 yrds later same, limp mode with DSC light coming on. Shut down again, and it drove back home.

It had almost 100 miles of dyno time, test drive before I got it back. Fresh gas. I filled with 92-93 non ethanol.

While in my "limp mode", it responds absolutely to no throttle but idles like a champ.

**No engine light codes thrown in all instances. Always DSC

Engine;
300 miles, 288/280 cams, Epic custom tune, Epic Motorsport headers, underdrive pulleys, Bimmerworld CSL air box, new fuel filter

The shop is going to come out to my house in the future with the High end scanner tools and we will go for a drive.

First conversation on the phone with shop briefly mentioned throttle positions sensors and/or related items; at the pedal, airbox, and elsehwhere (dont remember honestly).

Any thoughts?
Gary

[maupineda]

I was going to say TPS, but when I had an issue with mine it idled fine but would not respond to any pedal input. However this threw a check engine light. It also lit up the DSC lamp!

Check the linkage of the throttle bodies just to be sure as well as your connections to the TPS’s

[Vanne]

It's possible Randy's tune turns off the TPS light. The TPS would be the first thing I'd check.

[dptmachine]

I will look into it. Thanks for all input

[dptmachine]

I finally got some time to get to the shop and have it coded. My Blue tooth android product was not reading anything.

I took the car out 2x more and on one occasion, no limp mode. I went to the the shop this last Friday and on the way, limp mode. Shut it down, started back up and off to the shop. No other incident.

At the shop, and dropped a bunch of codes pre-ownership miles with the DSC, TPMS, right rear wheel speed sensor and low voltage. "OK" Lets reset. Went for a drive and only one code "pops" up. Open circuit for the TPMS system. The thought at that moment was it might be possible the TPMS system was cut or disabled when putting on the Flossman kit. The shop wanted to remember the relay was in the right rear?? I will have to look into it, or read follow-up comments here.

OK, leave the shop, and get down the road, and limp-mode. Turn back around and head to the shop. Scan again and the only codes are open circuit for TPMS and Right rear wheel speed sensor.

So my plan is to buy another R rear wheel speed sensor and investigate TPMS? Sound consistent?

OH!!, cruise control did not work on the way up. Will the TPMS open circuit disable cruise??

AC was not working either, the light was not coming on at the AC button. Could be from sitting all those years. Gremlins.

[Vanne]

AC not working is part of Limp mode, though still blows hot air? Not sure about the tpms as mine works on wheelspeed.. have you pulled a lot of wires during your setup? Or stock loom?


Sorry I can't be of more help, but I thought the tpms computer thingy is in your front right wheel wel?

[Michael9218]

Kind of weird that several of us are chasing gremlins at the moment. Mine will crank but not fire. Everything checks out. Randy even spent hours diagnosing my car remotely. He now has my ecu. We think it is either a bad ecu or a glitch in the software allowing the immobilizer to be active somehow in the background, even though my car has no ews.

Your symptom kind of sounds like a throttle actuator, but it should be throwing a code.

[AK72]

Originally Posted by dptmachine

I have been dealing with a gremlin. I got my car back from the shop and on my second drive, just a few miles from home, the car went into what I would call "limp mode". No response to throttle but would idle just fine. The DSC audio indicator and light went on. "I presume the audio beep was paired with the light". No engine lights. I drove it back home in second gear at idle.

Check a few resources online suggesting bad fuel, low voltage, transport mode, and then finally shut-off and restart to reset.

Went out next day, started right up-up no indicators and drove 15-20 miles.
I plugged in my OBDlinx mx blue tooth; no faults listed from memory? Voltage normal

Going out for another drive, OBDlinx left in, and went into limp mode. I shut it off in the middle of back country road, restarted and off again. 400 yrds later same, limp mode with DSC light coming on. Shut down again, and it drove back home.

It had almost 100 miles of dyno time, test drive before I got it back. Fresh gas. I filled with 92-93 non ethanol.

While in my "limp mode", it responds absolutely to no throttle but idles like a champ.

**No engine light codes thrown in all instances. Always DSC

Engine;
300 miles, 288/280 cams, Epic custom tune, Epic Motorsport headers, underdrive pulleys, Bimmerworld CSL air box, new fuel filter

The shop is going to come out to my house in the future with the High end scanner tools and we will go for a drive.

First conversation on the phone with shop briefly mentioned throttle positions sensors and/or related items; at the pedal, airbox, and elsehwhere (dont remember honestly).

Any thoughts?
Gary

I having same Issue every two weeks, on top my audio system and bluetooth gets disconnected, in my case she doing this with no mods on the car

[rueyme]

This sounds really interesting i didnt see your post since I haven't logged into this section for some time, but noticed you seem to have the same issues I been having.

I have a similar engine build with 288/280 cams, csl headers, epic tune, under drive pulley csl box etc. And get the same limp mode at around 80mph at mid load. Brake and traction control light also come on with beep.

Randy is also troubleshooting my issue, and he believes the airbox causes different glitches i assume because the mss70 is harder to tune without a maf.

You should log in with inpa and check the limp mode errors on the dsc60 interface. I was able to pull the errors from the dsc module and the codes usually are related to ecu errors bec the coding doesn't really work well with the dsc link in certain conditions.

The codes I pull all related to a refresh required to the ecu but since we are tuning it, its not as though we have the same issues as stock setups that encountered the error so definitely it is in the tune.

Randy was able to eliminate the limp mode but to this day I still have other errors that show up in the dsc or sometimes I get unusual glitches in the computer from time to time.

[dptmachine]

Back to the shop.

I had a little time to replace the Right Rear Passenger ABS sensor that was shown to be faulty in last scan; 1 mile out from the house and "limp mode". ABS is R/O. It will have to spend time under Randy's tuning prowess.

[Vanne]

shit, was really hoping that it was the rear sensor Gary, sad that it wasnt, did you replace the TPS? (trottle pos sensor)? i highly doubt its anything to do with the TPMS mate.

[Residentj3553]

My limp mode had to do with a Vanos piston seal not seated properly during rebuild. Might be worth looking into.

[Z4dugh]

dead battery?

[dptmachine]

Car is at the shop. AC is getting dealt with. So far, car does not enter limp mode with dsc off, recreated limp mode with dsc on according to the shop. The shop is working with Randg with Epic to source it out. I will keep updated, I am headed to the shop next week to swap out my 1966 mustang fastback; Griggs 350 suspension "tune and sort".

[dptmachine]

I have used 3 different batteries with same affect.

[dptmachine]

I swung by the shop. The limp mode is only reproduced with the dsc on. It thru all 3 tps at once on one trial. CAN relay on another trial. Randy with Epic is supplying different tweaks at this time. Some reproduce limp mode more quickly than others. We are on the hunt. When there is more declarative info, I will report.

[racerbruce]

Originally Posted by dptmachine

I swung by the shop. The limp mode is only reproduced with the dsc on. It thru all 3 tps at once on one trial. CAN relay on another trial. Randy with Epic is supplying different tweaks at this time. Some reproduce limp mode more quickly than others. We are on the hunt. When there is more declarative info, I will report.

It reads like a freakin' murder mystery....

[dptmachine]

The "possession" is over and all demons have been excised. Randy from epic set it straight. Initial tune and dyno was 342 with . I am not sure what "micro" adjustments have done to that number, I am just glad to have this solved. I did not get the specifics, but it was honestly mostly over my head.

[Vanne]

Glad to hear it bud let the good times roll!

[Michael9218]

My issue ended up being related to the instrument cluster being removed. Though my tune is allegedly ews delete, the ews sent a no go signal to the ecu after so many starts. Rather frustrating...

The instrument cluster was removed when the Aim dash was installed. I’ve now got the instrument cluster stripped down to a box and tied up under the dash. With it plugged in, I also get better fuel readings.