EATON Transmission Fault Codes list
Retrieving Fault Codes
1. Place the shift lever in neutral.
2. Set the parking brake.
3. Turn the ignition key ON but do not start the engine. If the engine is already running,
you may still retrieve codes, however, do not engage the starter if engine stalls.
4. To Retrieve Active Codes: Start with the key in the ON position. Turn the key OFF
and ON two times within five seconds ending with the key in the ON position. After
five seconds, the gear display begins flashing two-digit fault codes. If there are no
active codes the gear display will show code 25. If there are inactive codes PD
(Product Diagnostic mode) will be displayed. The vehicle will not start in PD mode.
You must turn vehicle key OFF and allow the system to power down to exit PD mode
before restarting. To start engine turn key off and wait for the transmission to
5. To Retrieve Inactive Codes: Start with the key in the ON position. Turn the key OFF
and ON four times within five seconds ending with the key in the ON position. After
five seconds, the gear display begins flashing two-digit fault codes. If no codes are
active, the gear display will flash code 25 (no codes).
6. Two digit fault codes will be displayed in the gear display. Record the codes. A one
or two second pause separates each stored code, and the sequence automatically
repeats after all codes have been flashed.
Clearing Fault Codes
1. Start with the key in the ON position. Turn the key OFF and ON six times within five
seconds, ending with the key in the ON position.
Note: If the codes have been successfully cleared, the service lamp will come on
and stay on for five seconds.
2. Turn the key OFF and allow system to power down.
Fault Codes Description
11 No ECU. Operation Test
12 Improper ECU Configuration
13 J1939 Control Device
14 Invalid Shift Lever Voltage
16 High Integrity Link
17 Start Enable Relay
25 NO CODES
26 Clutch Slip
27 Clutch Disengagement
28 Clutch System
31 Momentary Engine Ignition Interrupt Relay MEIIR
32 Loss of Switch Ignition Power Test
33 Low Voltage Supply
34 Weak Battery Voltage Supply
35 J1939 Communication Link
36 J1939 Engine Message Test
37 Power Supply
41 Range Failed to Engage
42 Splitter Failed to Engage Fault Codes Description
43 Range Solenoid Valve
44 Inertia Brake Solenoid Coil
45 Inertia Brake Performance
46 Splitter Solenoid Valve
51 Rail Position Sensor
52 Gear Position Sensor
56 Input Shaft Sensor
57 Main Shaft Sensor
58 Output Shaft Sensor
61 Rail Select Motor
63 Gear Select Motor
71 Unable to Disengage Gear
72 Failed to Select Rail
73 Failed to Select Gear
74 Engine Failed to Respond
75 Power Down in Gear
83 Shift Lever Missing
84 Shift Controller Device Not Configured
85 Shift Control Device Incompatible
The clutch is only needed at Start-up, when selecting a starting gear, and when stopping.
“D”, “M” and “L” can be selected at any speed.
If the down arrows continue to flash after selecting a starting gear even after pushing the clutch
pedal all the way to the floor and waiting several seconds, it means that the input shaft has not
slowed down enough to engage the gear. This could be caused by a misadjusted clutch or a faulty
clutch or clutch linkage.
When first starting up and after changing loads, AutoShift needs to adapt to the changing
conditions of the vehicle. If the transmission holds a gear while in “D”, simply pull the lever
towards you and the shift will be completed. This may have to be done several times before the
When AutoShift is downshifting in “D” it will not complete the shifts below a preset gear
(normally 9th gear in an 18 speed transmission) and the vehicle will “coast down” until the driver
gets back on the throttle.
Manual Mode “M” should be used whenever you want to control the shifts, such as moving
around the yard, going up a grade, or in poor traction situations.
Low Mode “L” should be used anytime you want to maximize the engine brake such as going
down a long grade, or when coming to a stop.
AutoShift can activate the engine brake to make shifts faster. This can happen even if
brake dash switch is off.
If a shift is required while in cruise, AutoShift will interrupt cruise while performing the shift and
automatically re-engage cruise after the shift is complete.
If AutoShift has detected a fault in the system you will see an “F” in the gear display. Note the
conditions at which the fault occurred (hot/cold, wet/dry, on a grade/flat terrain) and get the
vehicle to a service facility. Some faults will not allow the AutoShift to shift into other gears. You
can try to reset the system by powering the system down for 5 minutes which may clear the fault
long enough to get to a service facility.
If the engine is shut off, stalls while in gear, or a dash “–” appears on the gear display
after power up, perform the following procedure to try to get the transmission back into
1. Turn key “Off” and let transmission power down for at least 5 minutes.
2. Release parking brake and hold vehicle by using the brake pedal.
3. Depress clutch pedal but DO NOT push it all the way to floor making contact with the
4. Make sure shifter is in neutral.
5. Turn ignition key “On”
6. Slightly release the brake pedal to let the torque off the driveline. AutoShift will attempt to
shift into neutral. If neutral is achieved, the “N” will appear on the shift display and truck
NOTE: If the above procedure does not work, get the vehicle to a service facility