3 Diagnostics, Troubleshooting and Testing
28
Meritor WABCO Maintenance Manual MM-0112 (Revised 07-05)
The following definitions explain the function of each test.
Table E: Definitions
Component Test Function
Vehicle Voltages Monitors the voltage signals powering the ECU.
ABS Valves Cycles the valves, one at a time. With brake pedal applied, you should hear four short air exhausts, then one long
air pressure hold. A menu selection lets you choose from four or six valves. This test is used to verify valve
locations and correct wiring.
NOTE: The treadle must be applied to pressurize the brake chambers.
ATC Checks the ATC valve. You will hear a click as the valve cycles.
NOTE: TOOLBOX™ Software or the Pro-Link
®
Plus may be used to shut off ATC for dynamometer testing.
ABS Tractor Lamp Monitors the commanded (on/off) states of the ABS tractor lamp. Follow the screen prompts (1 On, 2 Off) to
change the status of the lamp on the instrument panel.
ABS Trailer Lamp Monitors the commanded (on/off) states of the ABS trailer lamp. Follow the screen prompts (1 On, 2 Off) to change
the status of the lamp on the instrument panel.
ATC Tractor Lamp Monitors the commanded (on/off) states of the ATC tractor lamp. Follow the screen prompts (1 On, 2 Off) to change
the status of the lamp on the instrument panel.
ABS/ATC Switches Checks the status of ABS and ATC/Deep Snow and Mud switches on the instrument panel.
Sensors Monitors the input to the ECU from the wheel. Vehicle must be stationary and wheels must be rotated during
this test.
Engine Datalink Checks wiring connections and response between the engine and the ECU.
Retarder Relay Activates the relay to verify function (a click will be heard). This test also checks wiring connections.
Retarder Datalink Checks wiring connections and retarder response between the retarder and the ECU.
To Next Page
Loading...
