Injector Harness Test - P0204 open circuit
04-15-2021, 06:44 PM
#1
Newbie
Thread Starter
Injector Harness Test - P0204 open circuit
Been a while since I used a forum, but recently got a 2003 E55 along with my son as he has me back into the cars ( and the M113k - we now have 3)
On the 2003...
Look for some feedback / assistance trying to find an electrical gremlin on a code that I am getting ( P0204 open circuit cylinder 4 ). I have disconnected the the harness from all injectors and ECU side and gone thru the pin outs. I am getting continuity on all 8 connectors as expected on from the ECU connector side to the Injector side ( control signal wire) , but on the other terminal of the injector connector (supply)I get a resistance of 0.9 Mega ohms to 1.4 Mega ohms on 7 connectors, but injector 4 ( the one with the issue, reading is 3.6 mega ohms).
The injectors were upgrade to 630's by PO so the injector connectors were changed to USCAR via solder joints but solder joints look good.
Question is - does this different in resistance make sense for all 7 vs injector 4, or should I expect an "open circuit" on all non control wire pins? Does have / know the pin for the supply side of the injectors? Visual inspection of the harness ( all parts that are not hidden by SC) look good. Moving harness around does not change resistance so was trying to rule out a short of some sort.
Thanks - and hope the above makes sense... its been a while since I have been troubleshooting electrical gremlins.
On the 2003...
Look for some feedback / assistance trying to find an electrical gremlin on a code that I am getting ( P0204 open circuit cylinder 4 ). I have disconnected the the harness from all injectors and ECU side and gone thru the pin outs. I am getting continuity on all 8 connectors as expected on from the ECU connector side to the Injector side ( control signal wire) , but on the other terminal of the injector connector (supply)I get a resistance of 0.9 Mega ohms to 1.4 Mega ohms on 7 connectors, but injector 4 ( the one with the issue, reading is 3.6 mega ohms).
The injectors were upgrade to 630's by PO so the injector connectors were changed to USCAR via solder joints but solder joints look good.
Question is - does this different in resistance make sense for all 7 vs injector 4, or should I expect an "open circuit" on all non control wire pins? Does have / know the pin for the supply side of the injectors? Visual inspection of the harness ( all parts that are not hidden by SC) look good. Moving harness around does not change resistance so was trying to rule out a short of some sort.
Thanks - and hope the above makes sense... its been a while since I have been troubleshooting electrical gremlins.
04-16-2021, 10:35 AM
#2
Super Member
Did they cut off the factory connectors at the injectors then to solder? I think a lot of us run the short adapters with connectors at each end for the USCAR injectors, which would be handy to switch and follow the fault code.
I'm guessing though that yours may be 'hardwired' in which makes it tougher. How hard would it be to re-do the solder with a fresh length of wire? It may visually look good but you never know what kind of corrosion has built up inside the copper wire...
I'm guessing though that yours may be 'hardwired' in which makes it tougher. How hard would it be to re-do the solder with a fresh length of wire? It may visually look good but you never know what kind of corrosion has built up inside the copper wire...
04-16-2021, 11:07 AM
#3
Newbie
Thread Starter
Did they cut off the factory connectors at the injectors then to solder? I think a lot of us run the short adapters with connectors at each end for the USCAR injectors, which would be handy to switch and follow the fault code.
I'm guessing though that yours may be 'hardwired' in which makes it tougher. How hard would it be to re-do the solder with a fresh length of wire? It may visually look good but you never know what kind of corrosion has built up inside the copper wire...
I'm guessing though that yours may be 'hardwired' in which makes it tougher. How hard would it be to re-do the solder with a fresh length of wire? It may visually look good but you never know what kind of corrosion has built up inside the copper wire...
Good point and yes - the original connectors were cut about 2-3" from the connector and soldered (vs adapters) . I have ordered new connectors and will plan on redoing #4 to start.
05-23-2021, 10:19 PM
#4
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2004 e55
Did you ever figure out the culprit? I'm dealing with the same issue now on 4 cylinders after a complete engine rebuild. Cut off the 630 adapters that were hardwired and still getting the same readout on the exposed wires.
