wali_r

The rev limiter kicks in at 4k rpm all the time in all gears. When driving, it does it too. Had replacement ecu installed at dealer. Used ECU was unlocked and programmed for this car. They said they tested the car, but apparantly did not take it past 4k rpm. Does anyone see any potential areas that needs to be looked at?

Fabio D

Change your crank position sensor bro, is not very expensive & maye the fulty on your car

Try & post some news very interesting issue, is not very common

Fabio Daniel

wali_r

Thanks, but I thought the crank pos sens, if faulty, would shut down the engine, but limit the eng speed.

I did get 2 fault codes, P0100 and p0110. I will have to look into these. No check engine light though.

RichardM98

Classic symptoms of failing CPS are starts cold but not when hot. That is you have to wait about 15min or more to restart.

DTC codes P0100 and P0110 are MAF circuit codes so make sure the connector is seated. Maybe disconnect and clean both male and female contacts with electrical contact cleaner and then reseat. Usually when MAF fails you get P0170 and P0173 which are fuel trim codes. Also you might buy some CRC MAF cleaner and clean the sensor. Post if you need DIY details.

It's important to keep the MAF sensor and the O2 sensors in good working order. When they stop working the exhaust gas becomes too rich and the catalytic convertor overheats and decomposes.

wali_r

Thanks. I will chk connections and clean everything. I hope that is all that it needs. Cars runs perfect as long as you keep the RPM below 4k.

Fabio D

I know the CPS fail when hot, but we have 2 cars yet in our workshop with 4-5k firing cut & the fault is the CPS, if you can put a new or used crank position only for proven is no bad.. the other cars our have with this fail provide by a tosated gearbox wiring harness, but really, in earlier models. never in a E55

maybe you can check with a Star Diagnosis the RPM sensors in the electronic gearbox board (inside the valve body gear group,)

Fabio Daniel

hcetzneb

I would agree with richard... If you have mass curciut codes check that out first. Cant tell you how many symptoms a bad mass will give you!!! Go with the codes first and if you hit dead ends go to other things... Those codes were set for a reason

wali_r

sent to dealer, they said MAF voltage is out of range. Suggested replacement. Replaced it, but no difference. I have a 04 CL500 for parts... would the CPS be the same for my 98? I could use that to test with.

MANARTAKAJI

i have e420 and have the same problem it comes and goes occasionally... but it is driving me crazy too! 4000 RPM and cuts...

wali_r

did you make any changes before it started doing that.

I am looking into the shift indicator that it may not sending the signal that it is no longer in P or N.

MANARTAKAJI

nothing.... but it seems to do that only when it's cold... means after driving for a while it revs all the way up to 6000... but could be a big disappointment some times....

i don't think that would be the shift indicator though....

hope you find what it is soon...