TemjinX2

Hi guys,

i've been having problems with my car a lot lately. Basically when i drive the car for an hr or so my car will throw a esp error and the car will go into limp mode.

I already replaced my throttle actuator, accelerator pedal. But i still get the problem. I bought a obdii reader and i got these codes.

code 4600 -voltage of supply circuit 87 undervoltage

code 4520 - the feedback through the transmission protection is not maintained.


I'm thinking of just replacing the 87 relays in the front sam. What you guys think?

TemjinX2

the other code its throwing is 207c

1qikctr

Tem, what do you mean by limb mode ? does the car stays in one gear and wont shift up and down?

TemjinX2

yeah its won't shift unless i manually shift. its stays at around 2000rpm or below..unless i manually shift and the supercharger is disengaged. if i turn off the car and turn it back on its back to normal.

TemjinX2

i couldnt find a 207c code.

the two codes i found closest that resemble it is

code 0207 = injection valve cy 7 (y62y7)

and code 2070 = transmission version cannot be checked because of undervoltage at component N15/3 (etc control module)

eddie1628

I have got this kind of problem with my C32 recently, I haven't got the code read, but the symptoms is similar to yours

Gas pedal replaced 3 mths ago and throttle valve actuator replaced 2 weeks ago, both motor and gearbox ECU software had been updated to the lastest version, but the car still goes in limp mode sometimes, or the rev is not stable

My mechanic guess it is because the motor ECU loss memory, which means the ECU still not calibratie with the new parts. He suggests me everytime I insert the key, turn to position 2 for a while, (all electronic. on, but engine off) and let the ECU calibrates with the throttle actuator again, do not start the engine rapidly

He is trying to send my car to have the ECU check up by local MB dealer. If the faulty of ECU is comfirmed, then I have to buy a new ECU or get a MOTEC

TemjinX2

i think its caused by the undervoltage. i just ordered some new 87 relays and i'm going to see if it fixes the problem.

mdncn2762

My car recently went into limp home mode and the supercharger disengaged. I re-seated the connector to the throttle body and re-seated the ECU connectors. It hasnt come back yet. I think the connectors were loose.

///AMG4EVER

Temjin - the problem is definetely electrical... did you replace the TB cable? is the TB cable tangled somewhere? Maybe on top of the SC or by the splitter overheating...

I had the same issues and the only thing I additionally replaced was the TB cable, it's an upgraded part and also longer.

I believe the other codes are just domino effects from the source.

Keep us posted.

1qikctr

I was told by mechanic there is a speed sensor on top of the tranny, and the oil leak form engine gasket has found its way to it. Till this day still dont know which sensor is he talking about... but the problem is gone after he cleaned it with Choke cleaner spray.

TemjinX2

yeah i replaced the throttle cable.

TemjinX2

this might be plasible because my valve covers have been leaking oil until i replaced them. i'll check it out tomorrow.

FrankW

all the years here that's the first time I see that code. lol sorry can't offer any help mike.

1qikctr

Let us know the update.

TemjinX2

i decided to try everyone's suggestion... I unplugged my tranny ecu plug, cleaned a bit and plugged it back in. I disconnected my ecu and reconnected it. I cleaned my egr valves. i checked fuses and relays. None of them looks burnt out. I cleared the codes. i'm still waiting on the engine relays i ordered but those are probably not gonna come till next week. I'll keep you guys updated.

i checked the valve cover area and i didnt see any excess oil. the shop i took it too...did a decent job cleaning up the oil.

1qikctr

Damm mike thats a whole lot of work ! By the way, where the hell is the tranny ecu plug at ??? I think i need to try to do that if my limb mode kicks it again lol sigh... 7 yr old car still holding up pretty decent.

TemjinX2

sorry i meant the transmission control module. THe plug is on the driver side of the transmission. it didnt help unfortunately. i'll wait on the engine relays and see if that helps.

1qikctr

Dang, i wonder what trigger the problem... headaches i feel your pain.

TemjinX2

man... i got a new battery hoping it was a battery issue. still have the same problem. I went to a mercedes shop when i had the esp error and plugged it into star.

I get the same two errors...mercedes code p2600 and p2525.

I check the esp module and it saids CAN communication error.

I did get a over boost cel and mis fire cels when i went 125mph in mexico when it was 40degrees out side.

I havent gotten a over cel or misfire since then.

The mercedes tech said its either a bad MAP sensor or i have a bad ecu tune.

I'm doubting its a map sensor because the error only happens at low speeds. I would imagine i would run lower boost at low speeds then at high speeds.

Is there any merit to a bad tune? Could a bad tune..leave a hole in my 2nd gear speeds?"