Multiplex Troubleshooting B-3
PA-1628Operator's ManualH3-45 COACH
Problem / Symptom Probable Causes Actions
None of the Multiplexed
functions are operating,
including the basic limp-
home functions (door
opening, flashers, wipers in
speed 1)
“FLIP REAR BREAKER TO
INITIATE I/O MODULES
PROGRAMMING” pop- up
message appears in the
DID
Note: The sunshades are
still functioning since these
are not multiplexed
The program version in the
MCM is different than the
program in the I/O modules and
the MCM is forcing all I/O
modules to stay inactive
1. Engage the auto- programming of the
I/O modules: Turn the ignition key to the
ON position, trip and reset circuit
breaker CB6.
2. The DID indicates "MUX
AUTOPROGRAMMING I/O MODULE
PLEASE WAIT" until the
reprogramming is complete.
Many of the non- essential
secondary functions are not
functioning (interior lighting,
driver's area lighting, wiper
speed 2 and intermittent).
Marker lights and clearance
lights are turned ON when
setting ignition to the ON
position.
The MCM module does not
receive 24 V power.
The DL0 (BBUS MUX) network
is not working. It could be
caused by a short on the
network, an open circuit, a
problem with the MCM or the
MCM being disconnected from
the network.
1. Check / reset circuit breaker CB6.
Check / replace fuse F1
2. Operate in limp-home mode by starting
the vehicle from the engine
compartment (REAR START). All
functions essential to drive are
available
To close and lock the door, pull the door
manually up to its closed position and it will
lock by itself. The door opening button is still
functioning
No temperature control in
the passenger area
Passenger temperature
display indicates two
dashes "--"
Problem with the temperature
sensor located in the
evaporator compartment air
intake or the sensor wiring
Instruct the driver to manually control the
temperature by playing with the passenger set
point. Set above 22°C (72°F) to heat and below
22° C (72°F) to cool
To Next Page
