Fault Code Guide

(pin) Press. Switch
C5.A
(pin) Sol. Output
C5.H
Status
AIR ON
OFF
Status
Test Mode
ON
Enter Test
Mode
Mode
Exit Test
(From CHM to BHM)
Solenoid
Output Test
(From BHM to CHM)
ON
OFF
(pin) Sol. Output
C5.H
OFF
Status
AMU
SOLENOID 0
FAULTS
Double click to
display fault
codes, Double
click again to exit.
You must enter Test Mode
before using the test buttons
to operate the outputs.
Please exit Test Mode when
finished.
Inputs to BHM: Outputs from BHM:
C5.B
C5.J
Status
AIR ON
OFF
Status
ON
OFF
C5.J
OFF
Status
AMU
SOLENOID 1
C5.F
C5.L
Status
AIR ON
OFF
Status
ON
OFF
C5.L
OFF
Status
AMU
SOLENOID 2
C5.G
C5.M
Status
AIR ON
OFF
Status
ON
OFF
C5.M
OFF
Status
AMU
SOLENOID 3
This template monitors and tests the Air Manifold Unit solenoid valves. Use Servicelink to determine which
AMU bank and pins correspond to the function you wish to test (e.g. suspension dump on AMU2 output pin
C5.L). When the function is activated by a smart switch on the dash and all necessary conditions are met,
the BHM will send a command to the CHM to activate the corresponding AMU solenoid valve.
The CHM will then respond back indicating that the solenoid output has been activated. The CHM also
sends the BHM the status of the pressure switch (note: system must be charged with air when performing
AMU solenoid tests). In Test Mode the solenoids can be tested using the buttons on this template, thus
bypassing the smart switches in the dash.
Note: Smart switches are tested in a separate template.
Note: Pressure switch status will be "Air On" when the output is ON for N.C. solenoids, and "Air Off" when
the output is ON for N.O. solenoids.
01/05/2006 f544752
Fig. 1, AMU Solenoids Template, Outputs from BHM
PTO and Pump Electrical Controls 54.38
Troubleshooting
Business Class M2 Workshop Manual, Supplement 22, September 2012300/10