Spicer TPCS Troubleshooting Guide - Manual (Page 27)

24
Service Codes
Group: 4C! (Code 15)
Display Control Communications (Code 15)
Yes
Turn on ignition.
Is
driver interface
completely
blank?
With vehicle running, measure battery
voltage across battery terminals.
Base vehicle power is out of range.
Refer to Service Manual
Does
measured
voltage match
battery voltage reading
obtained
in previous
step?
Repair harness power or ground
connections to driver interface.
Replace driver interface.
Switch ignition off.
Disconnect ECU connector.
Disconnect driver interface connector.
Switch ignition on.
Verify adequate voltage (9-32 Vdc) between
power (ECU harness connector pin K1) and
ground (ECU harness connector pin K2).
Is voltage within range?
Inspect fuses/
repair harness
to power ECU.
Is there
continuity?
Inspect and repair
faulty
communications
circuit in harness.
Is any circuit shorted?
Inspect and
repair faulty
wire or
connection.
Replace driver interface.
Switch on ignition.
Is driver
interface functioning
correctly?
Complete
With ignition switched on but engine
not running, measure battery
voltage across battery terminals.
Is voltage
reading > 19
volts?
Is voltage
reading < 9
volts?
Disconnect driver interface.
With ignition on, measure
voltage between:
DDM Display or OCP
Harness Pins Harness Pins
4 and 5 5 and 6
Base vehicle power is out of range.
Refer to Service Manual
Check continuity between:
ECU and DDM Display or OCP
Harness Pin Harness Pin Harness Pin
K3 6 9
J3 7 10
Check for communication circuits shorted to ground, power or
shorted to each other. Check between:
DDM Display Harness Pins or OCP Harness Pins
6 and 4 9 and 6
7 and 4 10 and 6
7 and 5 9 and 5
6 and 5 10 and 5
6 and 7 9 and 10
No
No
Yes
No
Yes
Yes
No
No
Yes
No
Yes
Yes
No
No
Yes
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.