Hello,

A few days ago, I was driving my SRT6 home from work and when I pressed down on the accelerator, the car pulled for a few seconds then the engine just died: absolutely no throttle response whatsoever. The gauges and radio were still on and the BAS ESP light was illuminated when I looked at the dash cluster. Panicking, I pulled the car over into the nearest driveway and popped the hood and checked if something disastrous had happened. Everything looked fine. I put it in park, turned it off, then turned it back on. No BAS ESP light was illuminated and I drove it home cautiously, but with no issues. Later that day, I tried to recreate the issue... and I did. When I put my foot into the throttle, the car did the exact same thing I mentioned earlier. Upon further inspection of the engine, the boot for my Needswings DCAI had slipped off the throttle body at the top rear of the engine. I have no idea how long it had been loose. Thinking that was the issue, I hastily fixed it and took it out for another drive... nope, the same problem persisted. I have also noticed the car shakes and rumbles noticeably when accelerating hard, just before the engine cuts out: it kind of feels like a rumbly V8 under the hood instead of the smooth V6 I'm used to hearing. The BAS ESP light is never on unless this happens. I took it to Advance and had them read any codes, but they said the car is code free.

What could the issue be? I emailed Rob and he suspected the throttle body or the gas pedal could be at fault. Other research has lead me to believe a MAP sensor or an ABS module is to blame.

Thanks for any info you guys can provide!

 

To clarify, this issue occurs when flooring the accelerator; there is no obvious issue when driving conservatively.

 

I have seen this (BAS ESP light and limp to stop)happen with comprised connections at the throttlebody. Some times with codes, sometimes not. I have normally seen codes when the pedal goes out of limit.

Chris

 

Happened to me at the track.....longest 1/4 mile of my life!!! I wasn't out 30 ft when it happened. Had to roll the rest of the way and park in the grass under a light pole.

 

So the throttlebody itself may not be bad, but just some connections?

 

Did this just happen one time? What ended up being the diagnosis and what did you do to fix it?

 

This (bas esp and limp to stop) happened on both my sons SLK32 and my SL55 more than a few times. In both cases, the throttlebody was not bad, it was the connector on the harness plugging into it. Later mercedes models actually had a short (male/female) extender harness that came glued into the throttlebody (presumably to seal/immobilize the connection). You may get away with merely cleaning the connector with a good contact cleaner (part of the mercedes service procedure for the TB IIRC).

it would most often happen after some hard acceleration (on more than one ocassion, I had just passed a line of cars on a winding road then crapped out and I had to roll to a stop looking like a D-bag).

On both cars, I tried cleaning the connectors and they would eventually fail again.

On my sons SLK32, I replaced the harness from from the ECU to the TB and the problem went away.

On my SL55, I added the male/female extender harness and the problem went away. (I was actually using it as a troubleshooting step as I expected the problem to persist and I could isolate it to either the harness connector or the TB .... but the problem went away and I left the extender harness in place)


I have the part number for the extender harness somewhere ($50 IIRC) and I also have part numbers for the housing and pins for a DIY re-connectorization ($12 or so I think)

hope that helps,
Chris

 

Thanks for the info! I was curious to know if you had a part number/price for that ECU to TB harness. I think I should try that first since it cured the SLK32 of the problem.

 

unfortunately, there is no number for that bit of harness that I put on the SLK32 as it is not available new. I removed it from a donor car with less than 12k miles.

the part number for the extender harness (MBZ description is "ignition cable") is 1131500028
and the best price now (including free shipping) is $66.75 from oediscountparts
https://www.oediscountparts.com/part...&siteid=215242

the descriptions for the plug housing and pins (pins come with a length of wire attached in various wire gauges ... 2 different gauges are used in this application) are a little vague. SO I bought an assortment. I will look them over and create a list for a DIY plug replacement if anyone is interested.

Cheers,
Chris

 

Thanks, man. I ordered the part and I'll give it a try. I'll let you know if it works.