go to Step 20

Less than 4
Ohms

Go to Step 11

Open or short in
vehicle harness.
Repair as
necessary and
go to Step 20

NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Is the voltage within the specified range?
9

At J­46711­1, DPIM Overlay, measure torque
enable voltage on pins 16 (Inverter B Torque
Enable) and 17 (Inverter A Torque Enable) of
the 24­way connector.
NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Is the voltage within the specified range?

10

1.
2.

3.

Turn OFF the ignition.
Disconnect the J­46711, TCM/VCM/
DPIM Breakout Harness, from the
DPIM 24­way connector. Leave the
OEM 24­way connector mated to the
J­46711.
At J­46711­1, DPIM Overlay, measure
resistance to ground on 12V battery return
pins 18, 19, 20, and 21 of the DPIM 24­way
connector.

NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Was the resistance within specification?

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

5­579

Allison H 40/50 EP

DTC 73­41 (DPIM2) Inverter A Encoder Power Supply Out­of­Range Low (cont’d)
Step

Action

Value(s)

Yes

No

Leave the ignition OFF.
Disconnect the DPIM 24­way and
OEM 24­way connectors from the J­46711,
TCM/VCM/DPIM Breakout Harness.
3. Connect the OEM 24­way connector to the
DPIM 24­way connector.
4. Disconnect the blue OEM 32­way connector
from the DPIM.
5. Connect the blue DPIM 32­way connector
of the J­46711, TCM/VCM/DPIM Breakout
Harness, to the DPIM connector ONLY
using J­50165, DPIM2 Adapter Harness.
Leave the J­46711 disconnected from the
blue OEM 32–way connector.
6. Turn ON the ignition.
7. At J­50165­3, DPIM2 Overlay, measure the
speed sensor supply Open Circuit Voltage
(OCV) at the blue 32­way connector by
measuring the voltage between pin 6 and
pin 22 of the blue 32­way DPIM connector.
Is the voltage within the specified range?

7.5­18V (nominal
~12V)

Go to Step 12

Go to Step 19

Short in vehicle
harness. Repair
as necessary and
go to Step 20.

Go to Step 13

11

1.
2.

12

1.
2.

3.

4.
5.

Turn OFF the ignition.
Disconnect the J­50165, DPIM2 Adapter
Harness, from the blue DPIM 32­way
connector.
Connect the J­50165, DPIM2 Adapter
Harness, to the blue OEM 32­way
connector ONLY.
Turn ON the ignition.
At J­50165­3, DPIM2 Overlay, measure for
voltage on pins 6, 8, 10, and 22.

NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Was voltage measured on any of the pins?

5­580

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

Section 5—DIAGNOSTIC CODES

DTC 73­41 (DPIM2) Inverter A Encoder Power Supply Out­of­Range Low (cont’d)
Step
13

Action
1.
2.
3.
4.

Value(s)

Yes

No

Short in vehicle
harness. Repair
as necessary and
go to Step 20

Go to Step 14

7.5­18V (nominal
~12V)

Go to Step 15

Open or short in
vehicle harness.
Repair as
necessary and
go to Step 20

Less than 4
Ohms

Go to Step 16

Open or short in
vehicle harness.
Repair as
necessary and
go to Step 20

Turn OFF the ignition.
Disconnect the P1 encoder connector.
At J­50165­3, DPIM2 Overlay, measure for
shorts­to­ground on pins 6, 10, and 22.
At J­50165­3, DPIM2 Overlay, measure for
shorts to other wires on pins 6, 8, 10, and
22.

NOTE: There will be continuity between pins 8
and 24 of the gray 32­way connector because
all motor speed sensor shield wires are spliced
together.
NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Were any shorts­to­ground or shorts to any
other wires found?
14

1.
2.

3.
4.

Leave the ignition OFF.
Connect the J­50165, DPIM2 Adapter
Harness, to the blue DPIM 32­way
connector. Leave it connected to the blue
OEM 32­way connector and leave the
P1 encoder connector disconnected.
Turn ON the ignition.
Check sensor supply voltage at the
P1 encoder connector on pin C.

NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Is the voltage within the specified range?
15

1.
2.

Turn OFF the ignition.
Leave the P1 encoder connector
disconnected.
3. Use J­39197, Jumper Wire Kit, to measure
resistance to ground on pin B of the encoder
connector.
Was the resistance within specification?

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

5­581

Allison H 40/50 EP

DTC 73­41 (DPIM2) Inverter A Encoder Power Supply Out­of­Range Low (cont’d)
Step
16

Action
1.
2.
3.
4.

5.

Leave the ignition OFF.
Leave the P1 encoder connector
disconnected.
Use J­39197, Jumper Wire Kit, to jumper
pins A and C on the P1 encoder connector.
Disconnect the blue DPIM 32­way
connector from J­50165, DPIM2 Adapter
Harness, leaving it mated to the blue
OEM 32­way connector.
Measure the resistance between pins 6 and
10 of the blue OEM 32­way connector.

Value(s)

Yes

No

Less than 4
Ohms

Go to Step 17

Open or short in
vehicle harness.
Repair as
necessary and
go to Step 20

Less than 4
Ohms

Go to Step 18

Open or short in
vehicle harness.
Repair as
necessary and
go to Step 20

NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Was the resistance within specification?
17

1.
2.
3.
4.
5.

6.

Leave the ignition OFF.
Leave the P1 encoder connector
disconnected.
Remove the jumper wire from the
P1 encoder connector.
Use J­39197, Jumper Wire Kit, to jumper
pins A and B on the P1 encoder connector.
Leave the J­50165 DPIM2 Adapter
Harness, mated to the blue OEM 32­way
connector ONLY.
At J­50165­3, DPIM2 Overlay, measure the
resistance between pins 10 and 22 of the
blue OEM 32­way connector.

NOTE: The vehicle OEM has responsibility
for all external wiring harness repair. Harness
repairs performed by Allison Transmission
distributors and dealers are not covered by
Allison Transmission warranty.
Was the resistance within specification?
18

Replace the P1 speed sensor.
Has the speed sensor been replaced?

Go to Step 20

19

NOTE: In most cases, the Dual Power Inverter
Module (DPIM) is not at fault. Investigate
thoroughly before replacing the DPIM.

Go to Step 20

Replace DPIM. Contact Technical Assistance
Center (TAC) at 1­800­252­5283 for
DPIM replacement authorization. TAC will
require a snapshot.
Is the replacement of the DPIM complete?

5­582

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

Section 5—DIAGNOSTIC CODES

DTC 73­41 (DPIM2) Inverter A Encoder Power Supply Out­of­Range Low (cont’d)
Step
20

Action
In order to verify your repair:
1. Clear the DTC.
2. Operate the vehicle under normal driving
conditions.
Did the DTC return?

Value(s)

Yes

No

Begin the
diagnosis again.
Go to Step 1

System OK

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

5­583

Allison H 40/50 EP

DTC 73­73 Inverter A Encoder Duty Cycle Out­of­Range
Overview:
DTC 73­73 is logged when the DPIM CAN message indicates that motor sensor A duty cycle is outside
calibrated parameters. This code was designed to detect faults in motor A sensors P1 and P2.
Actions Taken When DTC Sets:
• None
Possible Causes:
• P1 and P2 motor speed sensors
Tool Requirements:
• Universal Allison DOC®
• J­39700 Universal Breakout Box
• J­46711 TCM/VCM/DPIM Breakout Harness
• J­46708 Multimeter
• AMB­45 Amprobe Device “Megger”
Diagnostic Aids :
• This DTC tracks the duty cycle parameters from the DPIM’s EPCU2 CAN message and sets
when they are outside the calibration limits.
• The purpose of these DTC is to detect errors in the motor speed sensors operation for drive unit motor A.
• This code doesn’t light a lamp and has no restrictive mode; it will only show as historical when the
Universal Allison DOC® service tool is connected.
• Ideally this will allow the speed sensors to be replaced before more restrictive codes could affect
vehicle operation.
• DTCs 67­12 and 73­52 may be set with this DTC.
Step

Action

Value(s)
DOC®.

Yes

1

1. Install Universal Allison
2. Start the engine.
3. Record the DTC snapshot.
Has the DTC been successfully recorded?

Go to Step 2

2

Is code 73­73 shown in Universal Allison DOC®
history?

Go to Step 3

3

1.

Go to Step 4

Replace the P1 and P2 motor speed
sensors.

No

NOTE: Always replace P1 and P2 sensors as
pairs.
Is code 73­73 active?
4

5­662

In order to verify your repair:
1. Clear the DTC.
2. Operate the vehicle under normal driving
conditions.
Did the DTC return?

Begin the
diagnosis again.
Go to Step 1

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

System OK

Section 5—DIAGNOSTIC CODES

DTC 73–95 Motor A Torque Integrity

Figure 5–69.
Overview:
When the engine start button is pressed, the motor torque integrity test is run before allowing the engine
to crank. This code is logged if the motor did not rotate, did not rotate fast enough, or rotated in the wrong
direction, given a defined input.
Actions Taken When DTC Sets:
When DTC 73­95 is active, the following conditions will occur:
• Check System light illuminates
• Disable Inverter A
– Inverter A CAN enable will be removed. Vehicle can limp home on one motor only.
• Disable special mode
– HUSHTM mode will be disabled
Possible Causes:
• Motor speed sensor harnesses installed improperly
• Short­to­ground or opens on motor speed sensor wiring
• Faulty motor speed sensor
Tool Requirements:
• Universal Allison DOC®
• J­39700 Universal Breakout Box

Copyright © 2015 Allison Transmission, Inc. All Rights Reserved.

5­689

Allison H 40/50 EP

DTC 73–95 Motor A Torque Integrity (cont’d)
• J­46711 TCM/VCM/DPIM Breakout Harness
• J­50165 DPIM2 Adapter Harness
• J­46708 Multimeter
• J­39197 Jumper Wire Kit
NOTE: DPIM2 has a blue Motor A Terminal Protection Assurance (TPA) key and J­46711,
TCM/VCM/DPIM Breakout Harness, has a red Motor A TPA key. When servicing a DPIM2, use
J­50165, Adapter Harness, with J­46711, TCM/VCM/DPIM Breakout Harness. This will convert the
J­46711’s red connector TPA key to a blue connector TPA key and allow it to connect to a DPIM2.

Step

Action

1

Are any 13­XX series codes set along with this
code?

2

1. Install Universal Allison DOC®.
2. Start the engine.
3. Record the DTC snapshot.
4. Monitor TCM ignition voltage.
Is the voltage within the specified values?

3

Yes

No

Troubleshoot
these codes first.

Go to Step 2

Go to Step 3

Resolve voltage
problem. Go to
Step 20

Is code 73­95 active?

Go to Step 5

Go to Step 4

4

1.
2.

Go to Step 5

System OK

5

Remove the oil pan.
Is there excessive metal debris in the pan
indicating a mechanical failure?

Remove the
Drive Unit
and repair as
necessary. Go
to Step 20.