2001 Caravan Door Lock Switch Inoperative

About a month ago, our drivers side door lock switch stopped working on our
2001 Caravan Sport.
The key fob works ok, as well as the passenger side door lock switch.
I tried all the usual tricks, removed the IOD and BCM fuses for a short
time, but didn't help.
I removed the old switch and tested it, and it appeared to be somewhat off
the resistor values listed in my Haynes manual, so I replaced it with a new
one from my dealer for $15, which had the same values. No luck there. The
voltages on the connector appear normal too. The little green LED does light
up.
I suspect it might be the BCM, an expensive proposition without any
guarantees. I can't even find it.
Any ideas on what to do next? Any help would be appreciated.

 

The BCM is located under dash on the left side above and forward of the
E-brake mechanism. There are separate right and left circuits at the BCM.
You need to see 5.0 volts at the switch when unplugged, it is a MUX
(multiplex) circuit so simply plugging it in will result in some voltage
drop; in this way, the BCM can detect an open circuit. The failure of the
BCM, resulting in less than 5.0 volts, is common, resulting in Garbage In,
Garbage Out, and the locks will not operate from that switch circuit.

The easiest way to diagnose this is with the appropriate scan tool,
whereby you can read the voltages the BCM is receiving and compare them to
specs, and also command actuation. There may also be trouble codes that
inhibit operation until they are cleared.


Tom Showers
Former Chrysler tech

 

The BCM is located under dash on the left side above and forward of the
E-brake mechanism. There are separate right and left circuits at the BCM.
You need to see 5.0 volts at the switch when unplugged, it is a MUX
(multiplex) circuit so simply plugging it in will result in some voltage
drop; in this way, the BCM can detect an open circuit. The failure of the
BCM, resulting in less than 5.0 volts, is common, resulting in Garbage In,
Garbage Out, and the locks will not operate from that switch circuit.

The easiest way to diagnose this is with the appropriate scan tool,
whereby you can read the voltages the BCM is receiving and compare them to
specs, and also command actuation. There may also be trouble codes that
inhibit operation until they are cleared.


Tom Showers
Former Chrysler tech

Do I need to go to a dealer to scan the BCM?
Rick

 

you need a scan tool that can rease bcm codes and look for broken wires inthe
door boot if there is then the codes have to be erased before normanl operation
can happen

 

Thanks, will do. Probly means a trip to the dealer if I find a broken wire.
--
-bye,
Rick

you need a scan tool that can rease bcm codes and look for broken wires
inthe
door boot if there is then the codes have to be erased before normanl
operation
can happen