B52Bombardier1
04-13-2021, 04:57 AM
Hello,
I've read the one DTC P1638 thread discussion around here but overall, it was unhelpful. Tuner Pro RT won't let me kill the DTC P1638 code for "F" terminal control of the alternator. Tuner Pro can see these in the parameter tree view of any BIN that I look at. I can set it for nothing to happen and Tuner Pro will give me the asterisk indicating that I need to save the new setting. I then save the BIN.
But if I reopen the BIN, my changes with regard to DTC P1638 have not been saved. I've tried different PCM's with different BINS in the vehicle and they all still see a P1638 fault. I've tried different alternators and still get the fault - can two alternators have the same fault? Unlikely, but I suppose it could happen. I think I will stop by a local alternator rebuild shop and see what they say about F terminal problems.
I don't get a check engine light, just this annoying code that my scanner sees. My alternator appears to work well - 14.4 volts DC at idle without my fans running. With the fans running, its about 13.7 volts DC. And I only see a tiny amount of 0.012 volts AC at the battery with the engine running - the rectifier is ok.
Any ideas why Tuner Pro won't let me kill this DTC?
Many thanks,
Rick
I've read the one DTC P1638 thread discussion around here but overall, it was unhelpful. Tuner Pro RT won't let me kill the DTC P1638 code for "F" terminal control of the alternator. Tuner Pro can see these in the parameter tree view of any BIN that I look at. I can set it for nothing to happen and Tuner Pro will give me the asterisk indicating that I need to save the new setting. I then save the BIN.
But if I reopen the BIN, my changes with regard to DTC P1638 have not been saved. I've tried different PCM's with different BINS in the vehicle and they all still see a P1638 fault. I've tried different alternators and still get the fault - can two alternators have the same fault? Unlikely, but I suppose it could happen. I think I will stop by a local alternator rebuild shop and see what they say about F terminal problems.
I don't get a check engine light, just this annoying code that my scanner sees. My alternator appears to work well - 14.4 volts DC at idle without my fans running. With the fans running, its about 13.7 volts DC. And I only see a tiny amount of 0.012 volts AC at the battery with the engine running - the rectifier is ok.
Any ideas why Tuner Pro won't let me kill this DTC?
Many thanks,
Rick