That is the million dollar question.

I plan on trying a few things one at a time.

• Disconnect speed sensor wire behind the speedometer gauge, this will disable the cruise control but might also disable the ASR and not affect the ABS.
• Measuring the voltage signal of the TPS to the ABS/ASR module and seeing if I add an artificial signal/voltage, I can fool the module into thinking I am just idling and not above the 25mph threshold

Hmm... I might have to try some trickery myself. Hopefully this weekend.

Has anybody has success in disabling asr on a 1990 12v 300sl m103?

Ive been in limp mode for x3 years,

ive had an electrician check all voltages, replaced the precharge pump, asr ecu, egas controller, actuator, throttle sensor, cruise control position sensor, ovp relay, brake light switch, new fuses and probably more and still have a contact asr light and limp mode.

would disabling asr even take away limp mode if a problem is still present?

eagerly await a response

Disabling ASR may not cure limp mode. Limp mode is caused by throttle control (E-GAS), this is a different system vs ASR.

Have you checked fault codes on the throttle control (E-GAS) module? This should tell you what is causing limp mode.

The 300SL 129.060 chassis with M103 engine was never sold in USA, so there will be limited information from USA residents on this particular issue.

thanks for your reply, being an early model there is no diagnostic for asr so i can't pull codes from it.

i have tried a spare e gas controller off eBay, but can't be sure this was good as it was purchased off ebay