freddyo
12-05-2005, 09:13 PM
My DM is dead. I have it diagnosed as a bad FICM but....
The following is a synopsis of events regarding the current injector/FICM problem. I followed the SI manual (3/2005 edition) procedures to the letter and to the extent possible lacking certain J tools. I used the Tech 2 and a Fluke DMM for all diagnosis. It was done in the bush over a period of two days.
Shortly after passing through a patch of water the FICM switched off a group of injectors. I stopped and checked for DTC's. DTC's P0201, P0204, P0206, P0207 and P2146 were set. Any single bad injector circuit will cause this DTC combo. It was late in the day so I shut it off, set up camp, and started into the SI manual.
The next morning, in doing a visual check, I found a small hole had been abraded through the FICM case by a stainless braid covered fuel line that I had installed for a Baldwin secondary fuel filter. I suspect that this was the source of the soon to be discovered FICM problem. I patched the hole with epoxy, removed the stainless braid and re-routed the fuel lines so as to not cause future problems.
I started the vehicle to charge up the batteries (and with visions that something may have dried out and there would be joy). I found the same DTC's and used the Tech 2 to check out the other available data. I noticed that the balancing rate was +15 for 1, 4, 6, and 7 and -7 for 2, 3, 5, and 8. After running for fifteen minutes or so, the engine stopped running altogether. I checked the DTC's again and found that, in addition to the DTC's that were already set, DTC's P2149, P0202, P0203, P0205, and P0208 were set.
I started working through the diagnostic procedures. In checking cylinder 5 I found that both connectors on the injector showed continuity to ground with about 4 ohms resistance. According to the SI manual, this injector needed to be replaced. I completed the tests on the other injector connectors and found them all to have continuity with the FICM connectors and no shorts or inappropriate ground continuity. I checked the wiring at the ECM, FICM, and that leading to the injectors and found everything to be in apparent order. I replaced injector 5 with my spare with no difficulty.
After reassembling the vehicle I restarted it. It ran as initially, with only one group of injectors functioning. No joy. I checked the DTC's and found that DTC's P0201, P0204, P0206, P0207, P2146 and U0105 were set. With the engine still running I went back to the SI for some more research and while checking that out the engine stopped again. I checked the DTC's and found P0201-08, P1658, P2146, P2149, P2194, and U0105. According to the SI manual, these DTC's indicate a faulty FICM. I did a little more probing and found I was not getting battery power at the injector connectors with the ignition on though I was getting power at the FICM.
I'm awaiting an express shipment of an FICM from my GMC dealer.
Does anybody have any info that might bear on the situation? "Coulda', woulda', shoulda'" input would also be appreciated for future reference. I have learned on my own, the hard way, to only use SS braid when it can be completely isolated from everything else. That stuff is a flexible file.
Thanks.
The following is a synopsis of events regarding the current injector/FICM problem. I followed the SI manual (3/2005 edition) procedures to the letter and to the extent possible lacking certain J tools. I used the Tech 2 and a Fluke DMM for all diagnosis. It was done in the bush over a period of two days.
Shortly after passing through a patch of water the FICM switched off a group of injectors. I stopped and checked for DTC's. DTC's P0201, P0204, P0206, P0207 and P2146 were set. Any single bad injector circuit will cause this DTC combo. It was late in the day so I shut it off, set up camp, and started into the SI manual.
The next morning, in doing a visual check, I found a small hole had been abraded through the FICM case by a stainless braid covered fuel line that I had installed for a Baldwin secondary fuel filter. I suspect that this was the source of the soon to be discovered FICM problem. I patched the hole with epoxy, removed the stainless braid and re-routed the fuel lines so as to not cause future problems.
I started the vehicle to charge up the batteries (and with visions that something may have dried out and there would be joy). I found the same DTC's and used the Tech 2 to check out the other available data. I noticed that the balancing rate was +15 for 1, 4, 6, and 7 and -7 for 2, 3, 5, and 8. After running for fifteen minutes or so, the engine stopped running altogether. I checked the DTC's again and found that, in addition to the DTC's that were already set, DTC's P2149, P0202, P0203, P0205, and P0208 were set.
I started working through the diagnostic procedures. In checking cylinder 5 I found that both connectors on the injector showed continuity to ground with about 4 ohms resistance. According to the SI manual, this injector needed to be replaced. I completed the tests on the other injector connectors and found them all to have continuity with the FICM connectors and no shorts or inappropriate ground continuity. I checked the wiring at the ECM, FICM, and that leading to the injectors and found everything to be in apparent order. I replaced injector 5 with my spare with no difficulty.
After reassembling the vehicle I restarted it. It ran as initially, with only one group of injectors functioning. No joy. I checked the DTC's and found that DTC's P0201, P0204, P0206, P0207, P2146 and U0105 were set. With the engine still running I went back to the SI for some more research and while checking that out the engine stopped again. I checked the DTC's and found P0201-08, P1658, P2146, P2149, P2194, and U0105. According to the SI manual, these DTC's indicate a faulty FICM. I did a little more probing and found I was not getting battery power at the injector connectors with the ignition on though I was getting power at the FICM.
I'm awaiting an express shipment of an FICM from my GMC dealer.
Does anybody have any info that might bear on the situation? "Coulda', woulda', shoulda'" input would also be appreciated for future reference. I have learned on my own, the hard way, to only use SS braid when it can be completely isolated from everything else. That stuff is a flexible file.
Thanks.