TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CAUTION
Turn battery switch to "OFF" position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Test 2.
Check connections to pneumatic controller solenoids.
Disconnect CTIS wiring harness cannon from ECU, and disconnect connector from
solenoid. Check for continuity. If harness is faulty, repair connections (para. 3-131) or
replace CTIS wiring harness (para. 3-470).
Test 3.
Check for operation of pneumatic controller.
Refer to malfunction 3, test 2.
Test 4.
Determine if pressure switch is functional.
Refer to malfunction 3, test 3, steps 1 through 3.
END OF TESTING!
8. LOSS OF
AMBER WARNING LIGHT AND/OR OVERSPEED PRESSURE CHANGE
NOTE
The CTIS incorporates an overspeed warning and an automatic
pressure increase to prevent operation of the vehicle with
insufficient tire pressure. This system incorporates a sensor to
measure vehicle speed, a panel mounted flashing light, and a
connection to the vehicle blackout lights to prevent flashing of the
amber warning light when the vehicle is operating under blackout
conditions. The ECU periodically measures the speed of the
vehicle and compares the speed to programmed limits. If these
limits are exceeded, the warning light and automatic pressure
increase functions are actuated.
Test 1.
Determine condition of warning light.
Step
1. Ensure vehicle blackout light switch is "OFF." If warning light does not flash, replace
lamp with known good lamp.
Step
2. Select EMERGENCY setting on ECU to cause CTIS to deflate. Amber warning light
should flash as soon as emergency pressure is obtained (steady emergency mode light).
Amber warning light should go out when blackout switch is turned on.
NOTE
The ECU limits time spent in the EMERGENCY mode to ten
minutes. Emergency mode must be re-selected to maintain correct
test conditions.
Step
3. If warning light did not flash in step 2, disconnect blackout wire (wire #463) from CTIS
wiring harness. If this causes amber warning light to flash, check vehicle wiring harness
from source of blackout signal. Repair vehicle wiring harness connections as necessary
2-275
