mm33.fm Page -4 Thursday, June 5, 2008 10:04 AM TR A IL ER A B S TM Easy-Stop Trailer ABS Maintenance Manual No. 33 Revised 4-98 $2.
Service Notes Important Information This manual contains maintenance procedures for Meritor WABCO's Easy-StopTM Trailer Anti-Lock Braking System (ABS). The information contained in this manual was current at time of publication and is subject to change without notice or liability. You must follow company procedures and understand all procedures and instructions before you begin to service or repair a unit. Some procedures require the use of special tools for safe and correct service.
Table of Contents Asbestos and Non-Asbestos Fiber Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Section 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Section 2: System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Section 3: ABS Questions and Answers The Electronic Control Unit (ECU) . . . .
ASBESTOS FIBER WARNING NON-ASBESTOS FIBER WARNING The following procedures for servicing brakes are recommended to reduce exposure to asbestos fiber dust, a cancer and lung disease hazard. Material Safety Data Sheets are available from Meritor. The following procedures for servicing brakes are recommended to reduce exposure to non-asbestos fiber dust, a cancer and lung disease hazard. Material Safety Data Sheets are available from Meritor.
Section 1 Introduction Overview Section 1Introduction Figure 1.1 This manual describes how Meritor WABCO's Easy-Stop™ Trailer Anti-Lock Braking System (ABS) works; answers some basic ABS questions; outlines procedures on how to adjust, test, remove and install ABS components, as well as how to test for faults in the system by using Blink Code Diagnostics; and illustrates ABS components and wiring and plumbing installation diagrams.
Section 1 Introduction Easy-Stop™ Trailer ABS Parts Parts book PB-96133 lists Meritor WABCO Easy-Stop™ replacement parts. To obtain a copy, contact the Meritor Customer Support Center at 800-535-5560. What Is Meritor WABCO’s Easy-Stop™ Trailer ABS? How Trailer ABS Works Meritor WABCO’s Easy-Stop™ Trailer ABS is an electronic, self-monitoring system that works with standard air brakes.
Section 2 System Components ECU/Valve Assembly Sensor with Molded Socket 앫 12 volt 앫 Measures the speed of a tooth wheel rotating with the vehicle wheel. Section 2System Components 앫 Integrated ECU and ABS relay valve 앫 The 2S/1M Basic ECU/Valve Assembly does not have an external diagnostics connector. 앫 Produces an output voltage proportional to wheel speed. Figure 2.3 Figure 2.1 1002074a 1 2 1002072d 1 2 Sensor Spring Clip 앫 Holds the wheel speed sensor in close proximity to the tooth wheel.
Section 2 System Components Connection Cable for ABS External Valves Diagnostic Cable 앫 Three-wire cable with connector. 앫 Provides for blink code diagnostics and diagnostics using the MPSI Pro-Link® 9000 diagnostic tool. 앫 Connects the ABS external valve to the ECU. 앫 “Y” cable for use with 4S/3M configurations also available. 앫 Five-wire cable with over-molded connector to ECU on one end and SAE J1587 diagnostic connector over-molded on the other end. Figure 2.6 Figure 2.
Section 2 System Components Diagnostic Cable Mounting Bracket Diagnostic Cable Assembly with Diagnostic Tool 앫 Bracket used to mount the diagnostic cable assembly to the trailer. 앫 Diagnostic cable mounted to the bracket with a diagnostic tool connected to the SAE J1587 diagnostic connector. 앫 Protective dust cap included. Figure 2.10 Figure 2.13 1002081a 1002084a ECU/Valve Assembly Mounting Bracket 앫 Bracket used to remote mount the ECU/Valve Assembly to the trailer frame. Tooth Wheel Figure 2.
Section 2 System Components Installation Hardware Kit 앫 Contains Schedule 80 NPT pipe nipple fittings and Grade 8, 3/8-inch SAE bolts for proper mounting of ABS components to the trailer frame or reinforced air tanks. Figure 2.15 1003296a Easy-Stop™ Trailer ABS Warning Label 앫 Provides information about the operation of the ABS warning lamp and illustrates blink code fault locations. 앫 Label is self-adhesive and is mounted on the trailer near the ABS warning lamp.
Section 3 ABS Questions and Answers The Electronic Control Unit (ECU) The ABS Warning Lamp How do you activate the ECU? The warning lamp enables a driver to monitor the ABS at all times. Refer to the OEM operating manual for the mounting location of the warning lamp. Section 3ABS Questions and Answers What is the function of the warning lamp? In a constant-powered system, the ECU activates and then begins a self-diagnostic check of the system when you turn the ignition ON.
Section 3 ABS Questions and Answers Table C — Constant Power System Is Powered When Ignition Is Switched ON. Brakes Ignition Fault in System Vehicle Speed Warning Lamps (Trailer and Dash) Released OFF N.A. N.A. OFF Released ON NO Less than 4 mph ON for 3 seconds, then go OFF. Released ON NO Greater than 4 mph OFF Released ON YES N.A. ON Applied OFF NO Less than 4 mph ON for 3 seconds, then go OFF.
Section 3 ABS Questions and Answers Can you continue to operate a vehicle when the warning lamp indicates a fault? Yes. When a fault exists in the ABS, standard braking returns to the affected wheel, and the ABS still controls other monitored wheels. This lets you complete the trip. You should not ignore the warning lamp and should have the vehicle serviced as soon as possible after the lamp comes ON and stays ON.
Section 4 System Configurations Section 4System Configurations 2S/1M Trailer ABS Configuration Without External Diagnostics Capability Installation Diagram Figure 4.1 YE1 1 2 2 YE2 A B C D 1003292e A B C D Service/Control Lines Sensor Cables Service to Brake Lines (Delivery Lines) Air Supply/Emergency Lines 1 2 ECU/Valve Assembly (YE) Air Tanks For direct tank-mounted installations, see “How to Install the ECU/Valve Assembly,” in Section 6, "Component Replacement".
Section 4 System Configurations 2S/1M Trailer ABS Configuration with External Diagnostics Capability Installation Diagram Figure 4.2 YE1 1 2 2 YE2 A B C D 1002086f A B C D Service/Control Lines Sensor Cables Service to Brake Lines (Delivery Lines) Air Supply/Emergency Lines 1 2 ECU/Valve Assembly (YE) Air Tanks For direct tank-mounted installations, see “How to Install the ECU/Valve Assembly” in Section 6, "Component Replacement".
Section 4 System Configurations 2S/2M Trailer ABS Configuration Installation Diagram Figure 4.3 YE1 1 3 2 2 BU1 A B C D 1002087e A B C D Service/Control Lines Sensor Cables Service to Brake Lines (Delivery Lines) Air Supply/Emergency Lines 1 2 3 ECU/Valve Assembly (YE) Air Tanks External Valve (BU) For direct tank-mounted installations, see “How to Install the ECU/Valve Assembly” in Section 6, "Component Replacement".
Section 4 System Configurations 4S/2M Trailer ABS Configuration Installation Diagram Figure 4.4 YE1 YE2 1 3 2 2 (BU) (YE) BU1 A B C D 1002088e A B C D Service/Control Lines Sensor Cables Service to Brake Lines (Delivery Lines) Air Supply/Emergency Lines 1 2 3 ECU/Valve Assembly (YE) Air Tanks External Valve (BU) For direct tank-mounted installations, see “How to Install the ECU/Valve Assembly” in Section 6, "Component Replacement".
Section 4 System Configurations 4S/2M Trailer ABS Configuration Diagram for Lift Axle Applications (Forward Lift Axle Installation Diagram) Figure 4.
Section 4 System Configurations 4S/2M Trailer ABS Configuration Diagram for Lift Axle Applications (Rear Lift Axle Installation Diagram) Figure 4.
Section 4 System Configurations 4S/3M Trailer ABS Configuration Installation Diagram Figure 4.
Section 4 System Configurations Power Cable Wiring Diagrams Figure 4.8 4 OR 5 WIRE SCHEMATIC P/N 449 315 XX0 0 OR 894 60X XXX 0 (INDUSTRY STANDARD CABLE) ECU INTERNAL GROUND (5 WIRE CABLE ONLY) WHITE AND YELLOW TRAILER ABS WHITE INDICATOR LAMP (GROUND) IN TRACTOR POWER SOURCE BLUE (CONSTANT POWER) 7 WAY RED (STOP LAMP) GREEN AND WHITE TRAILER ABS INDICATOR LAMP GROUND ECU POWER CONNECTOR Trailers Produced March 1, 1998 or Later 1003302e Figure 4.
Section 4 System Configurations Power Cable Wiring Diagrams Figure 4.10 STOPLIGHT POWER CIRCUIT P/N 894 604 19X 2 3 CONDUCTOR CABLE BLUE WHITE BLACK BROWN YELLOW WHITE GREEN RED RED Connect to Easy-Stop™. RED Trailers produced prior to March 1998. GREEN INDICATOR LAMP 1003303c Figure 4.11 STOPLIGHT POWER CIRCUIT P/N 449 312 XX0 0 4 CONDUCTOR CABLE BLUE WHITE BLACK BROWN YELLOW GREEN WHITE RED RED Connect to Easy-Stop™. RED/WHITE RED Trailers produced prior to March 1998.
Section 5 Diagnostics WARNINGS Section 5Diagnostics To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service. The ABS is an electrical system. When you work on the ABS, take the same precautions that you must take with any electrical system to avoid serious personal injury. As with any electrical system, the danger of electrical shock or sparks exists that can ignite flammable substances.
Section 5 Diagnostics 앫 If the blink code lamp is flashing, count the number of flashes to identify the fault. Check Table D — ECU Part Number 472 500 011 0 Blink Codes to determine the problem. Follow the suggested corrective action. Using the Blink Code For ECU Part Number 472 500 011 0 without diagnostic connector: 1. Make sure the vehicle is stationary: 앫 Emergency brake ON 앫 Wheels properly chocked Figure 5.1 2. Provide 12 volts DC power (9.
Section 5 Diagnostics Diagnostic Tools For ECUs with External Diagnostic Connectors MPSI Pro-Link® 9000 Diagnostic Tool Diagnostic Activation Tool For ECU Part Numbers 472 500 001 0, 472 500 012 0 and 472 500 013 0. Figure 5.3 (Meritor WABCO Cartridge Model J 38500-404) The MPSI Pro-Link® 9000 diagnostic tool can test for existing and stored faults, read and clear fault codes, and test components, for Meritor WABCO tractor and trailer ABS. Figure 5.
Section 5 Diagnostics How to Test for Existing Faults Using the Normal Mode When you use Normal Mode diagnostics, the blink code lamp displays a numerical fault code sequence for each existing fault, one at a time. If the ECU stores more than one existing fault in memory, you must repair the first fault before Normal Mode diagnostics will display the second existing fault. In the Normal Mode, the lamp only identifies the component that needs repair; for example, THREE FLASHES = SENSOR BU1.
Section 5 Diagnostics Repair Existing Faults c. 앫 With Normal Mode diagnostics, you must repair an existing fault before you can identify and repair the next existing fault stored in ECU memory. Follow these steps: d. Immediately release the switch once for one second. The blink code lamp will go OFF. 앫 Turn off the power to the ECU. e. Immediately depress the switch once for one second. The blink code lamp will come back ON. 앫 Repair the fault. 앫 Repeat Normal Mode diagnostics. f.
Section 6 Component Replacement WARNINGS Section 6Component Replacement 1. To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury can result. The ABS is an electrical system.
Section 6 Component Replacement 4. Install the wheel hub carefully, so that the tooth wheel pushes against the sensor as you adjust the wheel bearings. After installation there should be no gap between the sensor and the tooth wheel. During normal operation a gap of 0.04-inch is allowable. 5. Sensor Output Voltage Test: Use a Volt/Ohm meter to check the AC output voltage of the sensors while rotating the wheel at approximately one-half revolution per second. Minimum output must be greater than 0.2 volts AC.
Section 6 Component Replacement 6. If the assembly being replaced is under warranty, please return it to the trailer OEM for replacement. Figure 6.5 1 How to Install the ECU/Valve Assembly NOTE The ECU/Valve Assembly is supplied with black protective caps on each sensor connector. When a sensor cable is not plugged into a sensor connector, the black cap must remain on the connector to protect it from dirt and contamination. See Figure 6.4. 1002104b 1 Figure 6.4 Bracket Plug unused port.
Section 6 Component Replacement b. Push the diagnostic tool firmly into the connector. Refer to Figure 6.8. 2. Connect the air lines to the ports. Follow the label markers installed when the air lines were disconnected. 3. Connect the sensor cables, external relay valve cable (if used), diagnostic cable, and power cable to the ECU/Valve Assembly. Use the black protective connector caps included with the replacement assembly to cover unused cable connectors.
Section 7 Sensor Adjustment & Component Testing How to Test Wheel Speed Sensors Section 7Sensor Adjustment & Component Testing NOTE At initial installation, no gap must exist between the sensor and the tooth wheel. After you install a hub, always check that the sensor is adjusted properly. Operating the trailer can cause a gap to develop between the sensor and the tooth wheel. If the gap exceeds 0.040-inch, the system may not function correctly.
Section 7 Sensor Adjustment & Component Testing Final Test Before Returning a Trailer to Service For ECU/Valve Assembly Part Number 472 500 011 0 (without external diagnostic connector) NOTE If you are testing ECU 472 500 001 0, contact the Meritor WABCO Customer Support Center at 800-535-5560. ABS Electrical/Hardware Installation Test 1. Provide 12 volts DC power (9.5–14 volts is an acceptable range) to the ECU/Valve Assembly. – Suggested power source: 12-volt battery. 2.
Section 7 Sensor Adjustment & Component Testing ABS Sensor Installation Test (ECU Part Number 472 500 011 0) 1. Remove power. 2. Raise both sensed wheels off of the ground. Apply air to emergency line to fill air tanks and release parking brake. 3. Provide 12 volts DC power (9.5–14 volts is an acceptable range) to ECU/Valve Assembly. (Make sure trailer ABS warning lamp and ECU blink code lamp operate correctly, as described in “ABS Electrical/Hardware Installation Test”.) 4.
Section 7 Sensor Adjustment & Component Testing For ECU/Valve Assembly Part Numbers 472 500 012 0 and S 472 500 013 0 (Units with External Diagnostic Connector) ABS Electrical/Hardware Installation Test 1. Provide 12 volts DC (9.5–14 volts is an acceptable range) to the ECU/Valve Assembly. Suggested power source: 12-volt battery. 2. Observe the ABS warning lamp and the blink code lamp on the ECU. Check the results in Table I .
Section 7 Sensor Adjustment & Component Testing 앫 If this does not occur, repeat Step 4. Sensor Installation Test (ECU Part Numbers 472 500 012 and 472 500 013 0) Purpose of Test: To verify proper sensor gap, sensor hook-up to the ECU, ABS valve operation, and pneumatic plumbing connections of the Meritor WABCO Easy-Stop™ ABS on a new trailer. 1. Remove power from the ABS. 2. Raise sensed wheels so that they may be rotated. 앫 Attach the emergency and control air lines to the trailer.
Section 7 Sensor Adjustment & Component Testing Trailer Identification An Easy-Stop™ Trailer ABS warning label is generally affixed to the trailer near the ABS trailer warning lamp. If this label is not on the trailer, let your supervisor know. Labels are available from Meritor WABCO. Ask for Part Number TP-95172. For additional assistance, contact the Meritor Customer Support Center at 800-535-5560.
Section 8 Appendixes Appendix A b. Release the switch. The blink code lamp will go OFF. Expert Mode Diagnostics c. Section 8Appendixes When you use Expert Mode diagnostics, the blink code lamp identifies and displays existing and intermittent faults consecutively in three-digit fault code sequences, with a short pause between each fault. Refer to Expert Mode Blink Code Example (4S/2M Configuration) and Table J — Expert Mode Fault Code, all in this section.
Section 8 Appendixes Blink Code Example (4S/2M Configuration) Expert Mode Figure 8.1 BLINK CODE 3-5-2 = CUT SENSOR CABLE FAULT CODE 1S 3 Flashes = I.D. = 4S/2M 1S OFF 1S OFF 1S OFF 2.5 S 1st Digit OFF 2.5 S = Light ON Power ON; ECU activated 2nd Digit OFF 2.5 S 3rd Digit OFF 2.5 S OFF 2.5 S Lamp stays ON after all fault code sequences have been displayed.
Section 8 Appendixes Table J — Expert Mode Fault Code (continued) Blink Code 1st Digit 2nd Digit 3rd Component or Digit (X) Location Cause or Type of Fault Solution 6 7 X Sensor YE2 Out of Adjustment Adjust sensor. 6 10 X Sensor YE2 Speed Erratic Check for excessive hub runout, a sensor gap that is too wide or damage to the tooth wheels. 7 3 X External Modulator (Red) Short to Power Check ABS valve and cable. Replace as required.
Section 8 Appendixes Appendix B Reconfigure Mode Blink Code Example (4S/2M Configuration) Reconfigure Mode Figure 8.2 1S 1S OFF 1S Power ON; ECU activated 1S OFF 1S 3 Flashes = I.D. = 4S/2M OFF 2.5 S 2.5 S OFF 2.5 S 3 Flashes = I.D. = 4S/2M OFF 2.5 S = Light ON S = Second(s) 2.5 S OFF 2.5 S 3 Flashes = I.D. = 4S/2M OFF 2.5 S 8 Rapid Flashes = ECU Reconfigured OFF 2.
Section 8 Appendixes When to Use the Reconfigure Mode d. Release the switch once for one second. The blink code lamp will go OFF. Use the Reconfigure Mode to (1) reconfigure the ECU if necessary (see Table K — ECU Reconfiguration); or (2) to clear repaired faults from ECU memory. (Refer to Figure 8.2 for a Reconfigure blink code example.
Section 8 Appendixes Appendix C Warning Lamp Diagnostics ECU Part Numbers 472 500 011 0, 472 500 012 0, and 472 500 013 0 If you do not have easy access to either the diagnostic tool or blink code lamp on the ECU, the ABS warning lamp on the trailer may be used to display blink codes. For Normal Mode: 앫 Turn ignition ON ONCE for ONE SECOND. 앫 Turn ignition OFF for ONE SECOND. 앫 Turn ignition back ON. – Warning lamp will display the blink code one time.
Meritor WABCO Vehicle Control Systems 2135 West Maple Road Troy, MI 48084-7121 USA 800-535-5560 meritorwabco.com Information contained in this publication was in effect at the time the publication was approved for printing and is subject to change without notice or liability. Meritor WABCO reserves the right to revise the information presented or to discontinue the production of parts described at any time. Copyright 1998 ArvinMeritor, Inc. All Rights Reserved Printed in USA Maintenance Manual No.
