Code Listings And Procedures
(Allison 4
th
Generation Controls)
(cont’d)
P071A
RELS Input
Fault
1. Check brake pressure switch, wiring, and connectors to
determine why RELS input is not being sent to the
TCM.
P071D
General
Purpose Input
Fault
1. Check input wiring, switches, and connectors to
determine why input states are different.
P0729, P0731,
P0732, P0733,
P0734, P0735,
P0736
Incorrect Gear
Ratio
1. Check:
a. Turbine and output speed sensor connectors are
tight, clean, and undamaged.
b. Speed sensor wiring harness has no opens,
shorts-between-wires, or shorts-to-ground.
c. Wiring harness has no opens, shorts-between-wires,
or shorts-to-ground.
2. Let vehicle idle with parking brake applied, wheels
chocked, and vehicle level. Check:
a. Correct dipstick is installed.
b. Fluid level is correct.
3. TCM calibration is correct for transmission model.
P0741
Torque
Converter
Clutch System
Stuck OFF
1. Check:
a. Engine and turbine speed sensor connectors are
tight, clean, and undamaged.
b. Speed sensor wiring harness has no opens,
shorts-between-wires, or shorts-to-ground.
c. Wiring harness has no opens, shorts-between-wires,
or shorts-to-ground.
2. Let vehicle idle with parking brake applied, wheels
chocked, and vehicle level. Check:
a. Correct dipstick is installed.
b. Fluid level is correct.
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