Fault Code Guide

Right Rear Wheel Sensor Troubleshooting (SID 004)
MID SID FMI Problem Test Test Result Action
136 004 10 Intermittent signal 7. Adjust the sensor. Using
the wheel sensor output
screen in Meritor PC
Diagnostics, spin the
wheel or drive the vehicle
and check for intermittent
or erratic signal.
Signal output OK Adjustment solved the problem.
Make sure brake chatter is not
causing the problem.
Signal output
incorrect
Check for intermittent wheel
sensor circuit connections. Cause
could be due to brake chatter.
Repair as needed.
136 004 11 Erratic signal Perform test 7.
136 004 12 Frequency too
high
8. Check sensor wiring
and connectors for
intermittent contact.
Wiring OK Suspect ECU at fault if problem
persists.
Wiring incorrect Repair wheel sensor circuit, as
needed.
Table 5, Right Rear Wheel Sensor Troubleshooting (SID 004)
Left Front Modulator Valve Troubleshooting (SID 007)
MID SID FMI Problem Test Test Result Action
136 007 03 Short to power
Inlet or outlet
circuit shorted to
battery supply or
another modulator
valve wire.
1. Measure the voltage
between pins 2, 10, and
11 of the X2 (black)
connector and a good
chassis ground.
No voltage at
either pin
Repeat test. Check circuits
378LFI, 378LFO, and 378LF– for
intermittent short to power. Check
above circuits for shorts to other
modulator valve wires. Repair as
necessary.
If problem persists, the suspect
ECU is at fault.
Measurable
voltage at either
pin
Repair short to power in circuit
378LFI, 378LFO, or 378LF–.
136 007 05 Open circuit
Inlet or outlet
circuit open.
2. Check the modulator
valve inlet and outlet
circuit resistance.
Disconnect the connector
from the valve and
perform the modulator
valve resistance test.
Resistance in both
circuits is within 4
to 8 ohms.
Check harness wiring circuits
378LFI, 378LFO, or 378LF–.
Resistance in both
circuits is not within
4 to 8 ohms.
Replace the modulator valve.
136 007 06 Short to ground
Inlet or outlet
circuit shorted to
ground.
3. Check the modulator
valve inlet and outlet
circuit resistance.
Disconnect the connector
from the valve and
perform the modulator
valve test.
Resistance in both
circuits is within 4
to 8 ohms.
Check harness wiring circuits
378LFI, 378LFO, or 378LF– for
short to ground. Repair as
necessary.
Resistance in both
circuits is not within
4 to 8 ohms.
Replace modulator valve.
Table 6, Left Front Modulator Valve Troubleshooting (SID 007)
Meritor WABCO Pneumatic Antilock Braking System
(ABS)
42.00
ABS System Troubleshooting
Business Class M2 Workshop Manual, Supplement 2, June 2002 300/9