Fault Code Guide

Right Front Modulator Valve Troubleshooting (SID 008)
MID SID FMI Problem Test Test Result Action
136 008 03 Short to power
Inlet or outlet
circuit shorted to
battery supply or
another modulator
valve wire.
1. Measure the voltage
between pins 3, 4, and 9
of the X2 (black)
connector and a good
chassis ground.
No voltage at
either pin
Repeat test. Check circuits
378RFO, 378RFI, and 378RF– 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
378RFO, 378RFI, or 378RF–.
136 008 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
378RFO, 378RFI, or 378RF–.
Resistance in both
circuits is not within
4 to 8 ohms.
Replace the modulator valve.
136 008 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
378RFO, 378RFI, or 378RF– for
short to ground. Repair as
necessary.
Resistance in both
circuits is not within
4 to 8 ohms.
Replace modulator valve.
Table 7, Right Front Modulator Valve Troubleshooting (SID 008)
Left Rear Modulator Valve Troubleshooting (SID 009)
MID SID FMI Problem Test Test Result Action
136 009 03 Short to power
Inlet or outlet
circuit shorted to
battery supply or
another modulator
valve wire.
1. Measure the voltage
between pins 10, 11, and
12 of the X3 (green)
connector and a good
chassis ground.
No voltage at
either pin
Repeat test. Check circuits
378LRI, 378LRO, and 378LR– 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
378LRI, 378LRO, or 378LR–.
136 009 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
378LRI, 378LRO, and 378LR–.
Resistance in both
circuits is not within
4 to 8 ohms.
Replace the modulator valve.
Meritor WABCO Pneumatic Antilock Braking System
(ABS)
42.00
ABS System Troubleshooting
Business Class M2 Workshop Manual, Supplement 2, June 2002300/10