TM-9-2320-283-13-P

0018-62

TM 9-2320-283-13&P

0018

ABS SELF TEST

Connect battery power (TM 9-2320-283-20).

NOTE

Normal operating range is 105–140 psi (724–965 kPa). The low air

pressure warning lamp and buzzer goes off at approximately 64–76

psi (441–524 kPa).

Start engine. Refer to TM 9-2320-283-10. Allow engine to run until air pressure builds up in reservoirs

and low air pressure warning lamp and buzzer go off.

NOTE

Assistant will help listen for air leaks by walking around vehicle

when service brake pedal is depressed.

Stop engine. Refer to TM 9-2320-283-10. Depress service brake pedal, and listen for air leaks. Hold

pedal down for a minimum of 10 seconds and observe front and rear air pressure gauges for any

noticeable drop in air pressure. If air pressure drops, refer to troubleshooting, WP 0009.

NOTE

Whenever ignition switch is turned on, the ABS ECU automatically

run through a self test and ABS amber warning light illuminates for

three seconds and goes off. If fault is found, ABS warning light will

stay on.

Turn on ignition switch. Refer to TM 9-2320-283-10. Observe ABS warning light (figure 88, item 1) on

center control panel (figure 88, item 2) illuminate for three seconds and then go off. At same time, listen

for all four modulators to cycle twice; a clicking sound should be heard. Turn ignition switch off.

Figure 88. ABS Warning Light Operation.

NOTE

Each modulator makes a popping sound when it releases air.

Depress and hold service brake pedal down, turn ignition switch on, and listen for all four modulators to

dump air. If no popping sound can be heard, refer to troubleshooting, WP 0009.

TM-9-2320-283-13-P - Page 164 of 400