michaelpappas
Member
233k miles
2004
just replaced engine wiring harness
March 2019 engine shuts off on freeway, won't turn over, no dash lights, nothing.
Local mercedes shop says engine wiring harness has rubbed through and is shorting out. They make some repairs to the harness. When I get it back it pretty consistently goes in limp mode. Eventually I loosen the zip ties around the area they repaired to look at their work. After doing this the limp mode goes away. Not inspiring confidence in their work or the future reliability of the wiring harness. eventually i can't get any link to the ECU to read codes but the scanner will power on and it will show battery voltage. I got some help with this here but was never resolved.
December 2019 the engine shuts off again on the freeway and i get it towed to a Mercedes dealer they says they've located more damaged wiring and repair. I drive it all the way from SLC to SF ( was on vacation when this occured) and it goes into limp mode 700 miles after the repair. I use my icarsoft MBII and still can't get any codes or info but like before the scanner will power on and show voltage.
I replaced the engine wiring harness yesterday to just have a clean slate as far as the limp mode goes and not trusting what other wiring damage exists that wasn't addressed in the previous repairs.
I'm at a loss for what to look into next. I need the OBDII to work to pass smog in CA and just for general peace of mind going forward. I tried getting it smogged yesterday and they couldn't communicate with the ECU. I followed the wiring coming from the OBDII port and looks to go out of the firewall through the non engine wiring harness. Any leads as to things to ohm out and check for continuity?
Thanks
Michael
2004
just replaced engine wiring harness
March 2019 engine shuts off on freeway, won't turn over, no dash lights, nothing.
Local mercedes shop says engine wiring harness has rubbed through and is shorting out. They make some repairs to the harness. When I get it back it pretty consistently goes in limp mode. Eventually I loosen the zip ties around the area they repaired to look at their work. After doing this the limp mode goes away. Not inspiring confidence in their work or the future reliability of the wiring harness. eventually i can't get any link to the ECU to read codes but the scanner will power on and it will show battery voltage. I got some help with this here but was never resolved.
December 2019 the engine shuts off again on the freeway and i get it towed to a Mercedes dealer they says they've located more damaged wiring and repair. I drive it all the way from SLC to SF ( was on vacation when this occured) and it goes into limp mode 700 miles after the repair. I use my icarsoft MBII and still can't get any codes or info but like before the scanner will power on and show voltage.
I replaced the engine wiring harness yesterday to just have a clean slate as far as the limp mode goes and not trusting what other wiring damage exists that wasn't addressed in the previous repairs.
I'm at a loss for what to look into next. I need the OBDII to work to pass smog in CA and just for general peace of mind going forward. I tried getting it smogged yesterday and they couldn't communicate with the ECU. I followed the wiring coming from the OBDII port and looks to go out of the firewall through the non engine wiring harness. Any leads as to things to ohm out and check for continuity?
Thanks
Michael