Return to index

CALL 800-631-5708

MERITOR WABCO TABLE OF CONTENTS Section 8

Appendixes

Appendix A

Expert Mode Diagnostics

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.

Expert Mode identifies:

	System configuration
	Components that need repair;
	Cause (or type) of fault, such as a cut sensor cable; and
	Number of times a fault has occurred.

The ECU stores intermittent and existing faults into memory in the order

in which they occur. However, the blink code lamp displays the most recent fault first.

How to Test for Intermittent Stored Faults Using the

Expert Mode

NOTE

Before you use Expert Mode diagnostics, be prepared to count and write down

the blink code lamp flashes for each fault.

1. The vehicle must be stationary to activate the blink code.

    Power the ECU with a minimum of 12 volts DC (9.5-14 is an acceptable range).

     The warning lamp on the trailer will come ON.

2. Identify the fault. If not already attached,

    plug the diagnostic tool into the diagnostic cable socket usually

    located on the right side of the trailer.

NOTES

For an alternate blink code access procedure, see "Warning Lamp Diagnostics"

     in Appendix C.

You can restart the Expert Mode fault sequence at any time by depressing

     the blink code lamp switch as described in Step 3 below.

3. Depress the blink code lamp switch located in the diagnostic tool two times for

    one second each time as follows:

a. Depress the blink code lamp switch once for one second.

     The lamp will come ON.

b. Release the switch. The blink code lamp will go OFF.

c. Depress the blink code lamp switch once for one second.

     The blink code lamp will come ON.

d. As soon as the blink code lamp comes ON,

    release the blink code button.

4. Determine whether or not there are Intermittent Stored faults in the system.

If there are no Intermittent Stored faults, the blink code lamp will come

back ON and identify the system configuration one time by displaying:

- 2 Flashes = 4S/3M

- 3 Flashes = 4S/2M

- 4 Flashes = 2S/2M

- 5 Flashes = 2S/1M

After the blink code lamp displays the system configuration once, the lamp will remain OFF.

If There Are Intermittent Stored Faults in the System

1. The blink code lamp will come back ON and identify the system configuration

one time by displaying:

- 2 Flashes = 4S/3M

- 3 Flashes = 4S/2M

- 4 Flashes = 2S/2M

- 5 Flashes = 2S/1M

2. The blink code lamp will go OFF for 2.5 seconds, come back ON for 2.5 seconds,

     and go OFF for 2.5 seconds.

· The blink code lamp will display the most recent fault in a three-digit fault code

sequence. For example, a fault code sequence of 3-5-2 reads

as follows:

First Digit

3 Flashes

= Sensor BU1

Second Digit

5 Flashes

= Cut Sensor Cable

Third Digit (X)

2 Flashes

= Number of Fault Occurrences

The blink code lamp will then go OFF for 2.5 seconds, then display each remaining fault code sequence.

When all fault code sequences have been displayed, the blink code lamp will come ON and go OFF, and remain OFF.

Blink Code Example (4S/2M Configuration)

Expert Mode

Figure 8.1

Table J - Expert Mode Fault Code Blink Code

Blink Code

Component or Location

Cause or Type of Fault

Solution

1^st Digit

2^nd Digit

3^rd-Digit (X)

0

0

0

No Faults

No-action needed.

3

5

X

Sensor BU1

Cable Break, Short Circuit

Check sensor, sensor cable and cable connection

3

7

X

Sensor BU1

Out of Adjustment

Adjust sensor.

3

10

X

Sensor BU1

Speed Erratic

Check for excessive hub runout, a sensor gap that is too wide or damage to the tooth wheels.

4

5

X

Sensor YE1

Cable Break, Short Circuit

Check sensor, sensor cable and cable connection.

4

7

X

Sensor YE1

Out of Adjustment

Adjust sensor.

4

10

X

Sensor YE1

Speed Erratic

Check for excessive hub runout, a sensor gap that is too wide or damage to the tooth wheels.

5

5

X

Sensor BU2

Cable Break, Short Circuit

Check sensor, sensor cable and cable connection.

5

7

X

Sensor BU2

Out of Adjustment

Adjust sensor.

5

10

X

Sensor BU2

Speed Erratic

Check for excessive hub runout, a sensor gap that is too wide or damage to the tooth wheels.

6

5

X

Sensor YE2

Cable Break, Short Circuit

Check sensor, sensor cable and cable connection.

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.

7

5

X

External Modulator (Red)

Cable Break or Open

Check ABS valve and cable.

Replace as required.

7

6

X

External Modulator (Red)

Short to Ground or Cable Damaged

Check ABS valve and cable.

Replace as required.

7

12

X

External Modulator (Red)

ECU/Valve Assembly Failure

Check ABS valve and cable.

Replace as required.

9

3

X

External Modulator (BU)

Short to Power

Check ABS valve and cable.

Replace as required.

9

5

X

External Modulator (BU)

Cable Break or Open

Check ABS valve and cable.

Replace as required.

9

6

X

External Modulator (BU)

Short to Ground or Cable Damaged

Check ABS valve and cable.

Replace as required.

9

12

X

External Modulator (BU)

ECU/valve Assembly Failure

Check ABS valve and cable.

Replace as required.

10

3

X

ECU/Valve Assembly Modulator (YE)

Short to Power

Check ABS valve and cable.

Replace as required.

10

5

X

ECU/Valve Assembly Modulator (YE)

Cable Break or Open

Check ABS valve and cable.

Replace as required.

10

6

X

ECU/Valve Assembly Modulator (YE)

Short to Ground or Cable Damaged

Check ABS valve and cable.

Replace as required.

10

12

X

ECU/Valve Assembly Modulator (YE)

ECU/valve Assembly Failure

Check ABS valve and cable.

Replace as required.

14

2

X

ECU

Data Erratic

Unexpected System.

14

3

X

Power Supply

Other Voltage

Repair vehicle power supply.

14

4

X

Power Supply

Under Voltage

Check vehicle voltage output and connector.

14

5

X

Power Supply

Current Low

Check for proper ground on power cable.

14

9

X

ECU/Valve Assembly

Internal Failure

Erase fault.

14

12

X

ECU/Valve Assembly

Internal Failure

Erase fault.

15

9

X

Electromagnetic Interference

Various

Contact the Meritor Customer Support Center, 800-535-5560.

15

12

X

ECU/Valve Assembly

Internal Failure

Contact the Meritor Customer Support Center, 800-535-5560.

X= Number of Fault Occurrences

TABLE OF CONTENTS

Page 39

Appendix B

Reconfigure Mode

Blink Code Example (4S/2M Configuration)

Reconfigure Mode

Figure 8.2

When to Use the Reconfigure Mode

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.)

Table K - ECU Reconfiguration

ECU Part Number

Reconfiguration Requirements

472 500 001 0

Manual reconfiguration required if ECU is installed on other than a 2S/2M configuration. See "How to Use the Reconfigure Mode".

472 500 011 0

2S/1M only. No reconfiguration required.

471 500 012 0 & 472 500 013 0

Automatic reconfiguration for upward configurations (e.g., 2S/2M to 4S/2M). If downward, manual reconfiguration required. Do NOT reconfigure the ECU unless system usage has changed. Contact the Meritor Customer Support Center at 800-535-5560 for assistance.

How to Use the Reconfigure Mode

NOTE

For an alternate blink code access procedure, see "Warning Lamp Diagnostics", in Appendix C.

The vehicle must be stationary to activate and reconfigure the ECU. Power the ECU with 12 volts DC (9.5-14 is an acceptable range).

If the diagnostic tool is not attached to the diagnostic cable: Plug the diagnostic tool into the diagnostic cable socket usually located on the right side of the sub-frame.

Activate the Reconfigure Mode: Press the blink code lamp switch three times for one second each time as follows:

a. Depress the blink code lamp switch once for one second.

b. Release the switch for one second. The lamp will go OFF.

c. Depress the switch once for one second. The blink code lamp will come back ON.

d. Release the switch once for one second. The blink code lamp will go OFF.

e. Depress the switch once for one second. The blink code lamp will come back ON.

f. Release the switch. The blink code lamp will go OFF.

4. The blink code lamp will display the system's identification three times. For example, three flashes identify a 4S/2M system. (Refer to the system identification example shown below.)

Figure 8.3

NOTE

To accept the ECU reconfiguration, you must depress the blink code lamp switch for three seconds during the third display of the system's identification.

5. During the third time the lamp displays the system's identification, depress the blink code lamp switch for three seconds and release the switch to accept the system reconfiguration.

6. The blink code lamp will flash rapidly eight times to acknowledge that the ECU is reconfigured. The lamp will continue to flash the system's identification until you turn OFF the power to the ECU.

7. If you repaired or replaced the ECU/Valve Assembly or ABS Modulator Valve, refer to "Final Test Before Returning a Trailer to Service" in Section 7, "Sensor Adjustment & Component Testing".

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.

The lamp is capable of displaying faults in Normal, Expert, Clear-All, and Sensor Installation Test modes.

System requirements:

· Trailer with mandated ABS (with ECU/Valve Assembly part number listed above).

· Tractor/trailer hook-up with switched ignition power on tractor/trailer connector or a DC-powered tester.

● Technician and assistant recommended.

Read the description of each mode and use the blink code tables for Normal, Expert, and Reconfigure/Clear-All modes that appear in this manual.

To display the blink codes on the ABS warning lamp:

Make sure the vehicle is stationary and that the trailer is hooked to a properly equipped tractor (see system requirements).

Remove power from the tractor and trailer (Turn off ignition).

Step on the brake pedal. Foot must remain on the brake for the entire procedure.

Provide Power. Turn on ignition for desired mode (Normal, Expert, or Clear-All). Once you enter the mode you plan to use, follow the instructions for that mode.

Reminder:

Brakes must be applied (foot on brake pedal) for the entire procedure.

NOTE

To exit any mode, release foot brake pedal and turn ignition off for AT LEAST 10 SECONDS.

For Normal Mode:

· Turn ignition ON ONCE for ONE SECOND.

· Turn ignition OFF for ONE SECOND.

· Turn ignition back ON.

- Warning lamp will display the blink code one time. See Table E -- Normal Mode Fault Code Table, in Section 5, "Diagnostics", for blink code identification.

For Expert Mode:

· Turn ignition ON ONCE for ONE SECOND.

· Turn ignition OFF for ONE SECOND.

· Turn ignition ON A SECOND TIME for ONE SECOND.

· Turn ignition OFF for ONE SECOND.

· Turn ignition back ON.

- Warning lamp will display the blink code one time. See Table J -- Expert Mode Fault Code, in "Appendixes", for blink code identification.

For Clear-All or Sensor Installation Test Mode:

· Turn ignition ON ONCE for ONE SECOND.

· Turn ignition OFF for ONE SECOND.

· Turn ignition ON A SECOND TIME for ONE SECOND.

· Turn ignition OFF.

· Turn ignition ON A THIRD TIME for ONE SECOND.

· Turn ignition OFF for ONE SECOND.

· Turn ignition back ON.

- The blink code lamp will flash rapidly eight times to indicate that stored faults have been cleared from ECU memory.

TABLE OF CONTENTS

Vehicle Control Systems

2135 West Maple Road

Troy, Ml 48084 U.S.A.

800-535-5560

www.meritorauto.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 discontinue the production of parts described at any time.

© Copyright 1998 Maintenance Manual No.33

Meritor WABCO Printed in the USA Revised 4/98

All Rights Reserved Please Recycle 16579/24240

Copyright © 2000 Ranco Trailers