Spicer TPCS Troubleshooting Guide - Manual (Page 31)

28
Service Codes
Group: 12C! (Codes 51,
52
, 53
, 54
, 55
, 56
)
PCU Solenoids (Codes 51, 52, 53, 54, 55, 56)
Replace ECU.
Note: ECUs are not a typical cause of problems. If an
ECU is replaced, the system should be carefully
rechecked to make sure the problem has been fixed
and does not reoccur.
Switch off ignition.
Disconnect harness at
PCU 10-way connector.
Are all
resistance
measurements
7-25 ohms?
Check for shorts between PCU connector
pins B, C, D, G, E, K and vehicle ground.
(Do not use multi-meter’s continuity “beep
mode,” as most meters will falsely identify
the 7-25 ohm coils as shorted.)
Are any pins
shorted to
ground?
Repair or replace
connections,
coils or PCU.
Disconnect ECU harness
connectors.
Check continuity of harness pins
shown in chart for given fault
code: PCU harness connector to
ECU harness connector.
Are circuits
continuous?
Repair or replace
harness.
Are
connections
OK?
Code 12C! Indicates one or more solenoid faults. Use service tool to determine the
specific solenoid. When the troubleshooting instructions refer to connector test
points, use chart select the pin test point for use with the particular fault code you
are diagnosing.
A
A
Measure at PCU harness connector.
Verify continuity between:
- A and F
- A and H.
Verify no continuity between any combination
of pins B, C, D, E, G, K on PCU harness
connector and K2 on ECU harness connector.
(Do not use multi-meter’s continuity “beep
mode,” as most meters will falsely identify the
7-25 ohm coils as shorted.)
Measure solenoid coil resistance on PCU 10-way connector.
Front (51): F – G Supply (54): H – C
Rear (52): F – E Deflate (55): H – B
Trailer (53): A – K Control (56): F – D
Repair or replace
connections, coils or PCU.
Solenoid/
Code
Any
Code
Any
Code
Front
(51)
Rear
(52)
Supply
(54)
Deflate
(55)
Control
(56)
PCU Harness
Connector
ECU Harness
Connector
H F G E K A C B D
K2 K2 D1 D2 E1 K2 B1 B2 B3
Trailer
(53)
Repair or replace
harness.
No
No
Yes
No
Yes
No
Yes
Yes