After several months of no ASR light with Limp Mode, the monster resurfaced its head this week.

1994 E420 with ASR

Here is my new experience:
Got ASR light with LM. Restart and went away. Several times this week. Once a day, sometimes twice or 3 times a day.

I read and reset the codes at least 3 times:

ABS/ASR Module - Pin 6: 30 Can data bus to N4/1 interrupted (this one from previous experience shows up whenever there is a code that triggers ASR/LM)

EA/CC/ISC Module - Pin 7 : 14 Close Throttle Position Switch (S29/3) (on top of accelerator pedal)

Diagnostic Module - Pin 19 : 6 Idle Speed Control Inoperative (this one from previous experience shows up whenever there is a code that triggers ASR/LM)

Fortunately after years of knowledge accumulated in this forum, as well as personal experience, I have been able to fix, troubleshoot and help others solve many ASR/Limp Mode issues.

I am convinced it is an intermittent issue with the switch on the accelerator (S29/3). The codes are consistent.

Questions:
1.- Is there a test for the switch, without having to be a contorsionist?

2.- I could not find it in Peachparts, where can I find it (not dealer, please)

3.- Have anyone replaced this switch, and level of difficulty? (I am 6'2", and getting down there is no easy task for me. I remember the struggle when I replaced the switch on the brake pedal (S9/1) years ago fixing another ASR issue!!)

Thanks

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

The code you need to concentrate on is the one in EA/CC/ISC.

Either a mis-adjusted accelerator cable OR bad switch on the linkage will cause ASR lamp & limp mode.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Have you looked it up on the EPC? It's under 30 Control / 15 Control, then #28, part number 1405450114, lists for $59, maybe dealer only.

Ooops, Fastlane has it, also $59 - search for switch, then idle speed contact sw

mbdoc...now that I think of it, my throttle cable guide broke, and I replaced it last weekend ! (little plastic piece at the end of the linkage)

I feel like a dummy

This may be the cause, the mis-adjusted accelerator cable...I remember turning the little wheel on the cable assembly to remove slack on the cable, it gave me a very responsive accelerator (touch and accelerate) ...may be I over did it, and it may be pulling too much on the cable, hence either activating (or not activating) the switch too soon (or not soon enough) !!

Will remove some of the tension later this evening and will drive around to see what happens.

I will report back.

Thanks for the responses !

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

Any results to report?

__________________
Thanks,

Joey

'88 560SL Pearl Black/Java 152K
'94 E320 Anthracite/Grey 89K


Previously:
'94 E420 Black/Bamboo
'90 300E
'71 280SEL 4.5