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KM816010
Page 17 of 44
MAINTENANCE MANUAL
Kenworth SmartWheel Troubleshooting Guide
16
C. Engine Retarder Does Not Work
C1-3. Possible cause: Bad retarder relay(s) in power distribution box.
C1-4. Possible cause: Problem in circuits C96JB or C98JB.
Check
Result
What To Do Next
C 1-3A
Turn on ignition. Press the retarder
buttons on steering wheel.
Listen for relay clicks in power distri-
bution box.
Click heard.
Determine which relay was clicking.
Remove this relay.
Use jumper wire from terminal
to terminal directly across
from it (common to normally open).
This retarder setting should now
work. If it does, replace relay.
Repeat for other relay if it also
clicked.
If retarder settings do not work with
jumper in place, Go to
C1-4
.
No click heard.
Go to
C1-4
.
Check
Result
What To Do Next
C1-4A
Unplug the 14 way connector from
the multiplex module.
Check continuity of ckts C98JB and
C96JB from pins 9 and 11 of the
connector to top terminal (coil-power
side) of each retarder relay position
in power distribution box.
Ckt has continuity.
Go to
C2
.
No continuity.
There is a break in the circuit
between the module and the power
distribution box. Trace each circuit,
checking connectors and wiring.
