DIAGNOSTIC CODE LISTINGS AND PROCEDURES
(ALLISON 4
th
GENERATION CONTROLS)
The following table presents information about the diagnostic codes which may
occur during the operation of the transmission. For additional information, refer to
TS3989EN Troubleshooting Manual for Allison 4
th
Generation Controls.
Code Listings And Procedures
(Allison 4
th
Generation Controls)
CODES
QUICK CHECKS
C1312, C1313
Retarder
Request
Sensor Fault
Use an Allison DOC™ diagnostic tool to read Retarder
Request Percentage. Check wiring for short-to-battery, ground
wire open, or short-to-ground.
P0122, P0123
Pedal Position
Sensor Fault
1. Check:
a. TPS connector is properly connected.
b. End of TPS cable is pulled out properly.
c. Engine fuel lever is in idle position.
d. Engine fuel lever provides proper amount of stroke
on TPS cable.
e. Wiring harness to TPS has no opens,
shorts-between-wires, or shorts-to-ground.
f. TPS for proper operation and resistance readings.
P0218
Transmission
Over
Temperature
1. Verify the overheat situation and check:
a. Correct dipstick is installed.
b. Proper
fl
uid level. Refer to CARE AND
MAINTENANCE section.
i. If
fl
uid level is incorrect—correct the
fl
uid
level.
ii. If
fl
uid level is correct—check for the cause of
overheating.
2. Check that the TCM and transmission connectors are
tight, clean, and undamaged.
P0602
TCM Not
Programmed
1. Recalibrate the TCM. If unable to recalibrate, replace
the TCM.
P0610
TCM Vehicle
Options Error
1. Update TCM calibration to match transmission
con
fi
guration.
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