TM 10-5410-228-24
2.8
UNIT LEVEL TROUBLESHOOTING PROCEDURES Continued.
26. NO AIR WHEN ESS CONTROL MODULE IS SET TO THE VENT MODE, MOBILE MODE,
INTERNAL POWER.
Turn ECV on.
Set ESS MODE switch to VENT.
Gain access to ECU front covers (see para 2.14.1).
Turn override button on solenoid valve SV1
counterclockwise (see para 2.14.4).
Check for rotation of NBC fan and recirculation fan.
Does
No
NBC fan
rotate?
Yes
Does
No
Push in override on
recirculation fan
SV9.
rotate?
Yes
Does
No
Remove connector plug from SV1.
Check shaft
recirculation fan
Test for 24 Vdc across connector plug pins.
coupling.
rotate?
Yes
Is
Yes
Replace solenoid
24 Vdc
valve SV1.
present?
No
Remove connector plug from SV9.
Test for 24 Vdc across connector plug pins.
Is
No
Yes
24 Vdc
Replace solenoid valve
present?
SV9.
1
2
