Gauges problem revisited
11-06-2007, 11:21 AM
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Gauges problem revisited This is the last of the bugs I have to work out on my swap (well this and an oil leak). The car is a 91 Z28 LS1/t56, dash and all wiring out of the donor car. The problem is my oil pressure gauge is maxed out, and my fuel level is bottomed out. I checked all my grounds and fuses, and they all appear to be fine. I have cel codes u1000 and u1301 (which for some reason you can't turn off).
According to the wiring schematic for the instrument cluster, oil pressure signal comes from the pcm and fuel level comes from class 2 data. The u1000 code is a class 2 communications error, so they may be linked (but abs, sir, and some other stuff (which I don't have) are also class 2 data stuff.)
Where is this problem coming from? Would a bad ground effect only those two gauges?
Also, on the ls1 fbodies, there is some sort of module mounted on the bottom side of the driver side frame rail (kind of below the abs stuff) that I am not using. I don't know what it is, and I can't find anyone that does. I don't mind that it is not there, I just want to make sure it isn't causing any problems.
According to the wiring schematic for the instrument cluster, oil pressure signal comes from the pcm and fuel level comes from class 2 data. The u1000 code is a class 2 communications error, so they may be linked (but abs, sir, and some other stuff (which I don't have) are also class 2 data stuff.)
Where is this problem coming from? Would a bad ground effect only those two gauges?
Also, on the ls1 fbodies, there is some sort of module mounted on the bottom side of the driver side frame rail (kind of below the abs stuff) that I am not using. I don't know what it is, and I can't find anyone that does. I don't mind that it is not there, I just want to make sure it isn't causing any problems.
11-08-2007, 05:39 PM
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What did you pull the PCM/harness/engine from? The F-bodies don't have a functioning oil pressure PID in the PCM as the signal from the OPS goes straight to the cluster.
I've attached a schematic for the instrument panel (thanks to joecar from EFILive forums for the image). Fuel pressure is class II, like you suspected.
FWIW, I have seen some bad oil pressure senders peg out at max pressure. Have you tried it with a known good sensor?
I've attached a schematic for the instrument panel (thanks to joecar from EFILive forums for the image). Fuel pressure is class II, like you suspected.
FWIW, I have seen some bad oil pressure senders peg out at max pressure. Have you tried it with a known good sensor?
11-08-2007, 07:19 PM
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Thanks for the replys guys. ryansm1, that is the schematic that I have been going by. The PCM and engine harness are out of a 2000 Z28, while every other harness (bcm is out of a 1999 Z28) are out of a 2001 Z28.
98camarod, I haven't checked the ops output before the instrument cluster, nor do I know for sure that the ops is good. I'll pick one of those up and try it. Now I did check the fuel level with hptuners...problem is, I ran it out of gas, but it did say I had .5gal, so maybe that problem could be instrument cluster related.
Any ideas about that module on the frame rail? I would like to figure out that u1000 code...but like I said, that could be from the lack of abs and air bags.
98camarod, I haven't checked the ops output before the instrument cluster, nor do I know for sure that the ops is good. I'll pick one of those up and try it. Now I did check the fuel level with hptuners...problem is, I ran it out of gas, but it did say I had .5gal, so maybe that problem could be instrument cluster related.
Any ideas about that module on the frame rail? I would like to figure out that u1000 code...but like I said, that could be from the lack of abs and air bags.
