EIS (N73) undervoltage & overvoltage
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Member
Joined: Jan 2018
Posts: 77
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From: Rocket City
'02 AMG C32, Mk5 VW R32, #2469/5000
EIS (N73) undervoltage & overvoltage
I'm going to pore over wiring diagrams to try and further troubleshoot, but I'm close to the end of my rope on this one.
Some time ago I had a no-start condition, and a scan using Giotto showed a Drive Authorization System failure, due to supply undervoltage on N73 (the EIS module). This happened just after I had a dead battery from letting the car sit for too long, and had attempted to jump start it without realizing that it can "kill" the EIS module. Lesson learned there. The old battery was not holding up well anyhow, so I replaced the battery and of course that made no difference to the situation. I sent my EIS to that Cluster Fix Texas place for repair, and the tech called me and said my module could not be repaired, but he could probably clone it to a replacement module. I picked up a used EIS that was "guaranteed good" (whatever that means) and sent it to Cluster Fix. A while later the tech told me all was well and he would be sending the repaired module back to me. He also included the old bad module, each module was marked with a sticker as to which was which. I took good photos of mine before sending it and was able to verify by various little dings and scuff marks that the modules were labeled properly.
I installed the repaired module, and still had the same symptoms (key turns, all dash lights come on, steering unlocks, the same buzzes and clicks happening that I'm used to hearing just before the starter turns... but nothing). I did some more scanning with Giotto, and now things are even worse. I'm no longer getting just the "undervoltage" code for the EIS, I'm getting undervoltage and overvoltage, and I also have some SRS electrical faults that I was not getting before.
Here are the codes logged under the airbag module:
9003 N2/7 (Restraint Systems Control Module) Control Unit Terminal 15r/15 Undervoltage
906D The Component Or The Signal Line To The Component B48 (Front Passenger Seat Occupied And Child Seat Recognition) Has Short Circuit To Ground
907A The Codings Of The Vehicle Data In Control Modules N2/7 (Restraint Systems Control Module) And N73 (Eis Control Module) Are Implausible
And here are the codes logged under the Drive Authorization module:
9002 Control Unit N73 (EIS Control Module) Is Faulty
9003 Undervoltage Supply
004 Overvoltage Supply
Any ideas would be greatly appreciated while I continue stabbing around in the dark. I'm going to call the Cluster Fix place tomorrow and ask how they know the repaired module was good after the work was done. I have no reason to believe they didn't do their job, but I feel like I'm trying to troubleshoot with extra unknowns because that part of the work was outside of my control.
Some time ago I had a no-start condition, and a scan using Giotto showed a Drive Authorization System failure, due to supply undervoltage on N73 (the EIS module). This happened just after I had a dead battery from letting the car sit for too long, and had attempted to jump start it without realizing that it can "kill" the EIS module. Lesson learned there. The old battery was not holding up well anyhow, so I replaced the battery and of course that made no difference to the situation. I sent my EIS to that Cluster Fix Texas place for repair, and the tech called me and said my module could not be repaired, but he could probably clone it to a replacement module. I picked up a used EIS that was "guaranteed good" (whatever that means) and sent it to Cluster Fix. A while later the tech told me all was well and he would be sending the repaired module back to me. He also included the old bad module, each module was marked with a sticker as to which was which. I took good photos of mine before sending it and was able to verify by various little dings and scuff marks that the modules were labeled properly.
I installed the repaired module, and still had the same symptoms (key turns, all dash lights come on, steering unlocks, the same buzzes and clicks happening that I'm used to hearing just before the starter turns... but nothing). I did some more scanning with Giotto, and now things are even worse. I'm no longer getting just the "undervoltage" code for the EIS, I'm getting undervoltage and overvoltage, and I also have some SRS electrical faults that I was not getting before.
Here are the codes logged under the airbag module:
9003 N2/7 (Restraint Systems Control Module) Control Unit Terminal 15r/15 Undervoltage
906D The Component Or The Signal Line To The Component B48 (Front Passenger Seat Occupied And Child Seat Recognition) Has Short Circuit To Ground
907A The Codings Of The Vehicle Data In Control Modules N2/7 (Restraint Systems Control Module) And N73 (Eis Control Module) Are Implausible
And here are the codes logged under the Drive Authorization module:
9002 Control Unit N73 (EIS Control Module) Is Faulty
9003 Undervoltage Supply
004 Overvoltage Supply
Any ideas would be greatly appreciated while I continue stabbing around in the dark. I'm going to call the Cluster Fix place tomorrow and ask how they know the repaired module was good after the work was done. I have no reason to believe they didn't do their job, but I feel like I'm trying to troubleshoot with extra unknowns because that part of the work was outside of my control.
Member
Joined: May 2021
Posts: 121
Likes: 22
From: Melbourne, Vic, Australia
C230K M271 CL203 2003 model
OK, I had something kind of similar happen when i swapped out the LCD screen in the dash.. there is a large electrical cable and connector going into the back of the dash binnacle, i had a lot of trouble getting it to align properly when re-assembling. If it is even slightly out of alignment, it was throwing up a lot of weird codes, similar to what you are seeing.. now these are quite complex electronic systems, and there maybe other reasons for what you are seeing, but just thought i would mention what i came across in case it helps you?...
