Spicer CTIS (Central Tire Inflation System) Troubleshooting Guide User Manual
Page 45
42
Service Codes
Deflate Signal (Codes 11,
12, 16)
Deflate Signal (Codes 11, 12, 16)
No
On 2-channel systems, use the
diagnostic tool to identify the faulty
channel: front or rear.
Using the diagnostic tool, manually
deflate the tires on the faulty channel.
Is the PCU
vent line or relief
valve plugged or
restricted?
Check for upper control line
leaks by using diagnostic
tool to place system into the
“Pressure Check and Hold”
mode and looking for steady
hold pressure.
Make repairs to faulty
components.
Fault is not active.
Reverify flowchart steps and
wait for fault to reoccur.
Repair PCU restriction and
recheck system.
Use diagnostic tool to manually
deflate the tires.
Replace PCU
relief valve.
Complete
Perform continuity check on
deflate solenoid. See
Solenoid Fault flowchart.
Was there a
problem?
Repair wiring and
recheck system.
Is there continuity?
Replace PCU and recheck system.
Note: While replacing the PCU, pay particular attention to
possible air line contamination (e.g., oil, water, particles) which
may suggest further air system maintenance needs.
No
No
Yes
Yes
Yes
No
No
Yes
Yes
No
Yes
While
deflating, is the
system (relief valve)
pressure within 1 psig
of nominal? *
* Reference vehicle build
information for nominal
relief valve pressure.
While
deflating, is the
system (relief valve)
pressure within 1 psig
of nominal? *
While
deflating, is the
system (relief valve)
pressure within 1 psig
of nominal? *
Check for continuity between:
PCU Sensor Harness
ECU Harness
n
i
P
r
o
t
c
e
n
n
o
C
n
i
P
r
o
t
c
e
n
n
o
C
A (round connector)
J (round connector)
or
or
B (oval connector )
H3 (rectangular connector)