Fault Code Guide

Diagnosing an ABS Lamp that Remains On
Symptom Test Test Result Action
Warning Lamp Stays On Test 1:
Use Servicelink or Meritor Toolbox to check for
J1587 fault codes (MID 136).
Are there any fault codes?
Yes Go to Test 2.
No Go to Test 3.
Test 2:
Is there an active fault code for the ABS
warning lamp circuit?
(Fault code is MID136 SID 023 FMI 05)
Yes
Refer to "Diagnosing
Warning Lamp Fault
Codes" in this section.
No
Go to Test 3.
Test 3:
Did any of the following happen since the
vehicle was last driven?
• Historic fault codes were cleared.
• A wheel sensor fault was corrected.
• The ABS ECU was reconfigured.
Yes
The ABS Warning
Lamp should go out
after the vehicle has
been driven over 4
mph (6.4 km/h).
No Go to Test 4.
Test 4:
1. Remove the ABS relay.
2. Locate circuit 376L1 that corresponds to
relay pin 87A (this is the circuit leading to
the instrument cluster.
3. Turn the ignition ON.
4. Check for voltage between circuit 376L1 at
the relay and ground.
12V (approx)
Check the ABS relay,
the contacts may be
stuck.
0V
Circuit 376L1 is
shorted to ground be-
tween the relay and
the instrument cluster.
Repair as necessary.
Table 2, Diagnosing an ABS Lamp that Remains On
Since the ABS warning lamp is controlled by three
redundant methods, it is unlikely that all three would
be inoperative at the same time. If the ABS warning
lamp does not turn on when the ignition is switched
on, manually ground pin B11 at the back of the in-
strument cluster (with connectors plugged in and ig-
nition ON). If the ABS warning lamp still does not
come on, replace the instrument cluster.
Meritor WABCO Pneumatic Antilock Braking System
(ABS)
42.00
ABS Lamp Troubleshooting
Business Class M2 Workshop Manual, Supplement 0, January 2002310/4