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Section 1

This manual contains service and diagnostic information for Meritor WABCO Enhanced Easy-Stop ^TM Trailer ABS with Power Line Carrier (PLC) capability.

Identifying Enhanced Easy-Stop Trailer ABS

To identify Enhanced Easy-Stop, check the indentification tag on the Electronic Control Unit (ECU). Figure 1.1. The part numbers for Enhanced Easy-Stop systems are

- 400 500 101 0 (2S/1M Basic for standard trailers)

- 400 500 104 0 (2S/1M Basic for dollies and steerables)

- 400 500 102 0 (2S/2M Standard)

- 400 500 103 0 (2S/2M, 4S/2M and 4S/3M Premium)

Figure 1.1

If you are servicing or using blink code diagnostics for Easy-Stop Trailer ABS (Easy-Stop ECUs with part numbers other than those listed above), please use Meritor WABCO Maintenance Manual 33.

If you are not able to identify the version, or to request service literature, please contact ArvinMeritor's Customer Service Center at 800-535-5560.

This manual does not contain Original Equipment Manufacturers (OEM) installation instructions. New installations require the following documentation:

- Enhanced Easy-Stop Basic (2S/1M): TP-20212

- Enhanced Easy-Stop Standard (2S/2M): TP-20213

- Enhanced Easy-Stop Premium (2S/2M, 4S/2M and 4S/3M): TP-20214

Enhanced Easy-Stop Trailer ABS Parts

Parts book PB-96133 list Meritor WABCO Easy-Stop replacement parts. To obtain a copy, contact ArvinMeritor's Customer Service Center at 800-535-5560.

For warranty information, contact ArvinMeritor's Customer Service Center (800-535-5560) and ask for TP-99128, Meritor WABCO Trailer ABS Warranty Procedure.

What Is Meritor WABCO's Easy Stop™ Trailer ABS?

Meritor WABCO's Easy-Stop™ Trailer ABS is an electronic, self-monitoring system that works with standard air brakes. In addition , Enhanced Easy-Stop includes Power Line Carrier (PLC) capability. PLC information is included in the ABS Q & A Section of this manual. The major components of the system are the Electronic Control Unit (ECU)/Valve Assembly, ABS relay (modulator) valve, tooth wheel and wheel speed sensor. Refer to Figure 1.2.

Figure 1.2

System Configuration

The ABS configuration defines the number of wheel speed sensors and ABS relay valves used in a system. For example, a 2S/1M configuration includes two wheel sensors and one ABS relay valve. A 2S/2M configuration includes two wheel sensors and two relay valves. A 4S/2M configuration includes four wheel sensors and two ABS relay valves.

A 4S/3M configuration consists of an ECU/dual modulator valve assembly and one external ABS modulator valve.

There is a specific ECU/valve assembly for each configuration:

- For 2S/1M Basic, the assembly consists of an ECU and a single modulator valve assembly.

- 2S/2M Standard and 2S/2M, 4S/2M and 4S/3M Premium, the assembly consists of an ECU and a dual modulator valve assembly (one valve that combines the function of two modulator valves). The 2S/2M Standard valve has only two sensor outlets and cannot be upgraded.

How Trailer ABS Works

Meritor WABCO ABS is an electronic system that monitors and controls wheel speed during braking. The system works with standard air brake systems.

ABS monitors wheel speeds at all times and controls braking during wheel lock situations. The system improves vehicle stability and control by reducing wheel lock during braking.

The ECU receives and processes signals from the wheel speed sensors. When the ECU detects a wheel lockup, the unit activates the appropriate modulator valve, and air pressure is controlled.

In the event of a malfunction in the system, the ABS in the affected wheel(s) is disabled; that wheel still has normal brakes. The other wheels keep the ABS function.

Two ABS indicator lamps (one on the dash and one on the side of the trailer) let drivers know the status of the system.

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