Put new alternator in for no other reason than the computer sensed it
was putting 17.1 volts for more than 2 seconds. After driving for a few
miles, it stalled once again. Immediatley checked code ; turned out to
be 53 again. After bench testing at the local auto parts store, and
doing an in vehicle test, both hot and cold, load and no load, both
alternators tested good. Same symptom, two different parts , I now feel
a little safer to assume that Paul has the right idea regarding the
computer incorrectly reading the voltage. While this voltage is being
sensed, the ECU will notoutput any data, thus the stall. Immediatley
after the stall, the vehicle is little harder starting. I have to put
the accelerator to the floor, feather it for 10-15 seconds until it
smooths out, then I can continue on my way. Sensor grounds thru the ECU
are tested and good.
=AB Paul =BB - 19 Dec 2005 01:03 GMT
> Put new alternator in for no other reason than the computer sensed it
> was putting 17.1 volts for more than 2 seconds. After driving for a few
[quoted text clipped - 9 lines]
> smooths out, then I can continue on my way. Sensor grounds thru the ECU
> are tested and good.
Please keep us informed! You never know when a similar problem
will pop up on another vehicle.
gobroncos - 22 Dec 2005 16:26 GMT
Hey Paul, solution is in the e-mail. Did u get it?
Mike Romain - 22 Dec 2005 17:58 GMT
On my GM alternator when it spikes like that it 'always' has a corroded
connection on one or more of the main battery cables or grounds.
The bad connection causes the voltage to spike while crossing it, it
would seem.
On yours, there is a ground strap from the bell housing to the body that
has a tendency to corrode or rot away, if so it can cause a high
reading.
The ground cable where it hooks to the engine is a sneaky one, but just
those side post terminals can easily be dirty enough to cause it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
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> Put new alternator in for no other reason than the computer sensed it
> was putting 17.1 volts for more than 2 seconds. After driving for a few
[quoted text clipped - 9 lines]
> smooths out, then I can continue on my way. Sensor grounds thru the ECU
> are tested and good.
gobroncos - 23 Dec 2005 02:20 GMT
Problem solved! Hi-Lo DMM indicated no transients while encountering
igniton shut-down. ECM incorrectly sensing overvoltage. Exchanged ECM
with one from the junkyard, problem is now solved. TKS Jim
=AB Paul =BB - 23 Dec 2005 04:06 GMT
> Problem solved! Hi-Lo DMM indicated no transients while encountering
> igniton shut-down. ECM incorrectly sensing overvoltage. Exchanged ECM
> with one from the junkyard, problem is now solved. TKS Jim
Excellent! It was your diagnosis that ruled everything else out.