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3-Step ABS Test

By January 2, 2013 No Comments

Roadside Inspectors are looking more closely at the trailer ABS operation. Does the ABS warning turn on and off with the ignition. If not, a violation is possible and the problem may be very simple to repair.

The ABS malfunctions are likely power or sensor related. The majority of ECU’s returned to the manufacturers are functional suggesting that the ABS repair procedures are not adequate.

A significant number of ABS malfunctions are power related. The Electronic Control Unit (ECU) requires 9.5v as specified by Technical Maintenance Council’s Recommended Practices 137. This means a minimum of 10 volts is needed at the nose socket with the trailer running lights on.

There is a simple 3Step process which eliminates wasted time and part replacement. As a necessary element, confirm the battery is delivering sufficient power exceeding 11 volts without an amperage load.

The FIRST STEP is to turn on the brake circuit to verify operation. The brake circuit is the secondary power source for the ECU. With the brake circuit, does the ABS lamp turn on and off? Does the ECU module chatter signifying the brake circuit is powering up the ECU?

The SECOND STEP is to turn on the auxiliary circuit to verify operation. Again, does the ABS lamp turn on and off? Does the ECU module chatter signifying the auxiliary circuit is powering up the ECU?

In both the FIRST and SECOND STEPS, if the ECU module chatters power is sufficient for operation. If the ABS warning lamp is not functioning, check connections and the lamp.

The THIRD STEP is reading the current faults whenever the ECU is powered and the ABS lamp remains on. The most common ABS faults are sensor related such as gap spacing and connections which requires reading the ECU. After repair, the stored fault should be cleared.

LITE-CHECK has the ideal solution with the Inspector 910B light, brake, and ABS tester for trailers. The circuit operation immediately identifies circuit faults with a description on the display with a fault alarm. The operation can be performed with the full function remote control as a one person operation. Thus, the FIRST STEP and SECOND STEP operations are simple and performed within seconds.

The real secret is the Inspector 910B software containing the ABS codes for MERITOR-WABCO, HALDEX, and BENDIX systems. The ONE ABS BUTTON will automatically identify the ABS manufacturer and read the current fault. The HELP button will display the recommended practice for repair. The STORED button shows stored faults and the CLEAR screen erases the stored fault from the ECU. ECU mileage can be read with the Inspector 910B.

Click to see our ABS video

The Inspector 910B is the comprehensive tool as a “ONE PERSON, ONE TOOL, ONE PROCESS™” operation for lights, brakes, and ABS.


Bob Blair, CEO