Allison  3000 MH TRANSMISSIONS FAULT CODES

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CODES QUICK CHECKS

MAIN

CODE

SUB

CODE

 

13 12 Check:

a. Battery direct ground and power connections are

tight and clean.

b. Vehicle batteries are charged.

c. Vehicle charging system is not over- or

under-charging.

d. VIM fuse is good.

e. VIM connections are tight, clean, and undamaged.

f. Vehicle manufacturer supplied wiring is correct.

g. ECU connectors are tight, clean, and undamaged.

ECU Input Voltage

Low

 

13 13

ECU Input Voltage

Medium Low

 

13 23

ECU Input Voltage

High

 

14 12, 23 Check:

a. Is transmission equipped with oil level sensor?

b. Engine speed sensor, output speed sensor,

temperature sensor, and oil level sensor are

working correctly.

c. Wiring harness has no opens, shorts to ground, or

shorts to battery.

Oil Level Sensor

 

21 12, 23 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.

Throttle Position

Sensor

CODES QUICK CHECKS

MAIN

CODE

SUB

CODE

 

22 14, 15, 16 Check:

a. Speed sensors and connectors are tight, clean, and

undamaged.

b. Wiring harness to sensors has no opens, shorts

between wires, or shorts to ground.

Speed Sensors

 

23 12, 13, 14,

15, 16

Check:

a. ECU connectors are tight, clean, and undamaged.

b. Shift selector connector is tight, clean, and

undamaged.

c. Wiring harness has no opens, shorts between

wires, or shorts to ground.

d. Shift selector(s) for proper operation.

Shift Selectors

 

24 12 Check:

a. Air temperature is below –32°C (–25°F)

• If yes, this is a correct response for

temperature.

• If no, check that main transmission connector is

tight, clean, and undamaged.

b. ECU connectors are tight, clean, and undamaged.

Sump Fluid

Temperature Cold

 

24 23 Verify the overheat situation. Check:

a. Correct dipstick is installed.

b. Fluid level is correct. Refer to CARE AND

MAINTENANCE section.

• If fluid level is incorrect—correct fluid level.

• If fluid level is correct—check for cause of

overheating.

c. Check if ECU and transmission connectors are

tight, clean, and undamaged.

Sump Fluid

Temperature Hot

CODES QUICK CHECKS

MAIN

CODE

SUB

CODE

 

25 00, 11, 22,

33, 44, 55,

66, 77

Check:

a. Speed sensor connector is tight, clean, and

undamaged.

b. ECU connectors are tight, clean, and undamaged.

c. Fluid level is correct. Refer to CARE AND

MAINTENANCE section.

d. Wiring harness to sensor has no opens, shorts

between wires, or shorts to ground.

Output Speed

Sensor

 

26 00, 11 Check:

a. TPS for proper operation, related harness for

opens and shorts.

b. Serial connection to engine is tight, clean, and

undamaged.

c. SCI wiring harness has no opens or shorts.

Throttle/Engine

Coolant Source Not

Detected

 

32 00, 33, 55,

77

Check:

a. Correct dipstick is installed.

b. Fluid level is correct. Refer to CARE AND

MAINTENANCE section.

c. Main transmission connector is tight, clean, and

undamaged.

d. ECU connectors are tight, clean, and undamaged.

e. Wiring harness has no opens, shorts between

wires, or shorts to ground.

C3 Pressure Switch

Open

 

33 12, 23 Check:

a. Main transmission connector is tight, clean, and

undamaged.

b. ECU connectors are tight, clean, and undamaged.

c. Wiring harness has no opens, shorts between

wires, or shorts to ground.

Sump Oil

Temperature Sensor

Failure

CODES QUICK CHECKS

MAIN

CODE

SUB

CODE

 

34 12, 13, 14,

15, 16, 17

a. Recalibrate ECU, if possible.

EEPROM b. Replace ECU if not possible to recalibrate.

 

35 00, 16 Check:

a. ECU connectors are tight, clean, and undamaged.

b. VIM connectors are tight, clean, and undamaged.

c. Vehicle manufacturer supplied wiring has correct

power and ground connections.

d. Power connections are battery direct.

e. Ground connections are battery direct.

f. Ignition switch connections are correct.

Power Interruption

Real Time Write

Interruption

 

36 00, 01, 02

a. If able, recalibrate ECU; if not, replace ECU.

b. Check that ECU is compatible with TransID level

(36 01).

c. Troubleshoot TransID wire and circuit for short to

battery (36 02).

Hardware/Software

Not Compatible

 

42 12, 13, 14,

15, 16, 21

22, 23, 24,

26

Check:

a. Main transmission connector is tight, clean, and

undamaged.

b. ECU connectors are tight, clean, and undamaged.

c. Wiring harness is not pulled too tight, and there is

no damage, chafing, or screws through harness.

d. Wiring harness has no opens, shorts between

wires, or shorts to ground.

e. Unauthorized repairs have not been made.

f. Change harness (optional).

Short to Battery in

Solenoid Circuit

CODES QUICK CHECKS

MAIN

CODE

SUB

CODE

 

44 12, 13, 14,

15, 16, 21,

22, 23, 24,

26

Check:

a. Main transmission connector is tight, clean, and

undamaged.

b. ECU connectors are tight, clean, and undamaged.

c. Wiring harness has no opens, shorts between

wires, or shorts to ground.

Solenoid Circuit

Short to Ground

 

45 12, 13, 14,

15, 16, 21,

22, 23, 24,

26

Check: a. b. c.

a. Main transmission connector is tight, clean, and

undamaged.

b. ECU connectors are tight, clean, and undamaged.

c. Wiring harness has no opens or shorts.

Solenoid Circuit

Open

 

46 21, 26, 27 Check:

a. Main transmission connector is tight, clean, and

undamaged.

b. ECU connectors are tight, clean, and undamaged.

c. Wiring harness has no opens, shorts between

wires, or shorts to ground.

d. Replace ECU.

Solenoid

Overcurrent

 

51 01, 10, 12,

21, 23, 24,

35, 42, 43,

45, 46, 53,

64, 65,

XY*

Check:

a. Output 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. Correct dipstick is installed.

d. Fluid level is correct. Refer to CARE AND

MAINTENANCE section.

Offgoing Ratio Test

(During Shift)