P1635 low 5v feed circuit one
09-18-2006, 10:41 AM
#1
P1635 low 5v feed circuit one How is this corrected? I checked & the feed is low (should be 4.5 to 5 volts w/ power on, engine not running). Is it protected by a fuse? This is the voltage feed from the PCM to the MAP sensor. Cannot clear code, so either the PCM is the problem or there is circuit protection somewhere. Any ideas? Thank-you.
09-18-2006, 01:16 PM
#3
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The +5V outputs should be current limited inside and there
may be a fuse in the picture too. If you see a smal but non-
zero voltage on the PCM connector pin, it may be one of
the driven sensors drawing excess current. Low like in
millivolts, more likely a short to ground. Start with PCM
fuses, then follow the wire around and start unplugging
(key on, engine off) sensors looking for the voltage to
release and go back to normal. Keep an eye out for wire
harness chafing or pinches that could make a short to
chassis or block. If you want to cut (and resolder) the
wire that's a last resort to determine if there is a short
you can't see.
may be a fuse in the picture too. If you see a smal but non-
zero voltage on the PCM connector pin, it may be one of
the driven sensors drawing excess current. Low like in
millivolts, more likely a short to ground. Start with PCM
fuses, then follow the wire around and start unplugging
(key on, engine off) sensors looking for the voltage to
release and go back to normal. Keep an eye out for wire
harness chafing or pinches that could make a short to
chassis or block. If you want to cut (and resolder) the
wire that's a last resort to determine if there is a short
you can't see.
