So, I was finally bitten by the ETA wiring bug.
Symptoms were;
- During normal driving, ASR light illuminates and car switches to limp-home mode
- Shorting pins 1 and 6 on the 38pin socket does not turn off limp-home
- No CEL or codes for the first few miles
- Eventually get, code 6 on the DM for 'high idle'
- Engine idles fine
So I studied the fine work of Pete from the V12 Uber Alles, Repair Help for Mercedes Benz S600 V12 W140 site and prepared for the worst. Instead of cutting into the harness for the ETA, I just removed it and opened the non-control side of the case. There I found lots of rotten wiring, but, as noted by Pete, none to the control side of the unit. In fact, my wiring to the control side was a ribbon cable. And, my PC board was vertical instead of horizontal in the ETA.
So I spent my Saturday rewiring, which was tedious and painful because I had to make my own diagram of the PCB. It was different from what Pete had documented and the connection numbers were obscured by someone who seemed to think that more is better, even when soldering!
Several hours and about 55 feet of the wire recommended and I was able to get things back under control. See the pics below for more fun.
Some notes;
- You will need a security bit set to remove the screws of the ETA cover
- It's a good time to replace the ETA gaskets (intake manifold to ETA and ETA to MAF)
- It's a good time to replace the PCV tubing that connects to the back of the ETA
I reinstalled the ETA today and performed the relearn procedure and WOW! What a nice smooth power curve I have now.
Thanks to Pete, Brett, Jonathan, Robert and Dietrich for all their posted brain power and advice.
Symptoms were;
- During normal driving, ASR light illuminates and car switches to limp-home mode
- Shorting pins 1 and 6 on the 38pin socket does not turn off limp-home
- No CEL or codes for the first few miles
- Eventually get, code 6 on the DM for 'high idle'
- Engine idles fine
So I studied the fine work of Pete from the V12 Uber Alles, Repair Help for Mercedes Benz S600 V12 W140 site and prepared for the worst. Instead of cutting into the harness for the ETA, I just removed it and opened the non-control side of the case. There I found lots of rotten wiring, but, as noted by Pete, none to the control side of the unit. In fact, my wiring to the control side was a ribbon cable. And, my PC board was vertical instead of horizontal in the ETA.
So I spent my Saturday rewiring, which was tedious and painful because I had to make my own diagram of the PCB. It was different from what Pete had documented and the connection numbers were obscured by someone who seemed to think that more is better, even when soldering!
Several hours and about 55 feet of the wire recommended and I was able to get things back under control. See the pics below for more fun.
Some notes;
- You will need a security bit set to remove the screws of the ETA cover
- It's a good time to replace the ETA gaskets (intake manifold to ETA and ETA to MAF)
- It's a good time to replace the PCV tubing that connects to the back of the ETA
I reinstalled the ETA today and performed the relearn procedure and WOW! What a nice smooth power curve I have now.
Thanks to Pete, Brett, Jonathan, Robert and Dietrich for all their posted brain power and advice.