TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 3. With wheel valve still connected to tire, disconnect wheel valve and air manifold from
hub, and check for air loss from air manifold. Place air manifold in container of water
and look for air bubbles. Persistent air bubbles from air manifold indicates faulty wheel
valve.
a. If wheel valve does not leak, dry thoroughly and install.
b. If leaking, replace or repair wheel valve (para. 3-456 or 3-457).
Step 4. After correcting malfunction, start engine (TM 9-2320-272-10) and press RUN FLAT to
override ECU warning. System will then equalize all tires and inflate to selected tire
pressure mode.
Test 2. Determine any non-tire related cause of four mode light indication.
Step 1. Inspect air supply lines between pneumatic controller, quick exhaust valves, and each
wheel for leaks, cracks, damage, or restrictions.
Refer to malfunction 1, test 1, step 1.
Step 2. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals
(para. 3-460 or 3-461).
Step 3. Check operation of pneumatic controller by listening for clicking noise when selecting
mode change. If click is not heard, replace or repair pneumatic controller (para. 3-454).
CAUTION
Turn battery switch to "OFF" position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Step 4. Replace ECU with known good ECU and operate CTIS (para. 3-468).
END OF TESTING!
3. FIVE INDICATOR LIGHTS FLASHING
NOTE
The ECU has a self-diagnostic capability which prevents opera-
tion of the CTIS when key elements or components of the system
malfunction. When the ECU shuts down due to such system mal-
function, the condition will be indicated by the flashing of all five
mode lights on ECU selector panel. Since it is unlikely that the
CTIS would operate properly, there is no option to override the
ECU until the problem is corrected. An indication of five flashing
lights can be caused by any of four conditions:
Test 1. Check air lines to tires.
Step 1. Inspect air lines between pneumatic controller and quick exhaust valves for leaks,
cracks, damage, and restrictions.
Refer to malfunction 1, test 1, step 1.
Step 2. Inspect air lines between quick exhaust valves and wheels for leaks, cracks, damage,
and restrictions.
Refer to malfunction 1, test 1, step 1.
Step 3. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals
(para. 3-460 or 3-461).
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