4. Start engine.
5. Using Allison DOC, check for active codes.
6. If codes are not active with test TCM
installed, then turn ignition OFF and
reinstall original TCM.
7. Restart engine and check again for active
DTCs.
Is DTC P274D still active with the original TCM
and inactive with a test TCM?

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

SIL 11-TR-22
July 25, 2022
Page 35 of 40

DTC P274D Transmission Converter Temperature Sensor Circuit
High (SPN 3823 / FMI 3) (cont'd)
Step
7

Action
1.

2.

Remove J-39700 Universal Breakout Box,
and all related harness adapters from
vehicle, if installed.
Install or reconnect all OEM connectors, if
needed.

NOTE: TCM 80-way connector bolt must be
tightened to 2.0-3.2 N·m (18-28 lb in).

Value(s)

Yes

No

Review
Diagnostic
Aids for this
DTC. Begin the
diagnosis again.
Go to Step 1

System OK.
Clear inactive
DTCs and return
equipment to
service.

3.

Acquire new Allison DOC snapshot while
operating the equipment under same
conditions, if possible, noted in failure
records from Step 1.
Did DTC P274D return?

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

SIL 11-TR-22
July 25, 2022
Page 36 of 40

DTC P274F Transmission Converter Temperature Sensor Over
Temperature Condition (SPN 3823 / FMI 15)
BULKHEAD
SOCKET

B
Q
C
D

A
P
b

R

c

S
E

T
F

M

N

Z

a

f

g

e
d

V

U

G

M
L

L

Y
X

Y
K

K

J

J

X

W

W

H

H

a

f

g

e
d

V

U

G

D

D

A

B

C

C

B

LOCK-UP
BODY

B

P

B

R
S

T
F

41

60

21

40

1

20

Q

b
c

80

E

C
D

LOCK-UP
BODY
SOCKET

A

A

A

A

61

CONVERTER TEMP
SENSOR
CONNECTOR

LOCK-UP
BODY
CONNECTOR

12-24 Ω

N

Z

END VIEW OF TCM
80-WAY CONNECTOR

K
B
C

SUMP TEMP
SENSOR
D
B
CONVERTER
TEMP SENSOR
A

131
119
158
154

B

CONVERTER TEMP
SENSOR
SOCKET

A
A

BULKHEAD
CONNECTOR
Q

31

X

19

T

58

b

54

H

75

B

TCM
HSD3

VBAT

LSD3
ANALOG RETURN
SUMP TEMP (+5V)

158
175

CONV TEMP (+5V)

ANALOG INTERFACE

BULKHEAD
CONNECTOR

6189057

Circuit Description
A converter temperature sensor monitors the fluid temperature in the torque converter. This test determines if the
fluid temperature in the torque converter is too high.
Conditions for Setting the DTC
The DTC will set when the TCM detects the fluid temperature in the torque converter is greater than 141° C
(285° F) for more than 5 seconds.

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

SIL 11-TR-22
July 25, 2022
Page 37 of 40

DTC P274F Transmission Converter Temperature Sensor Over
Temperature Condition (SPN 3823 / FMI 15) (cont'd)
Action Taken When the DTC Sets
• The TCM illuminates the CHECK TRANS light.
• DTC is stored in TCM history
Conditions for Clearing the DTC
The DTC will automatically become inactive and deactivate the Check Trans light if the fluid temperature returns
within normal operating limits for at least 2 seconds.
Use Allison DOC to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM
history if the vehicle completes 60 warm-up cycles without the DTC recurring.
Diagnostic Aids
NOTE: DTC P274F may occur in equipment with history of DTC P274C. Follow the diagnostic steps in
DTC P274C before proceeding to the diagnostic steps for this DTC. Repairing the condition that sets DTC
P274C will likely eliminate DTC P274F.
• Using Allison DOC, monitor the transmission converter fluid temperature to verify that it rises in cycles
and then stabilizes.
• Converter fluid temperature can rise rapidly during converter mode operation with a large differential between
engine and turbine speeds (such as torque converter stall). Operating in this condition for extended periods
can cause a converter overtemperature condition. Converter fluid temperature will become stable under
normal operating conditions with lockup engaged.
• A stuck or freewheeling stator can cause poor equipment performance and lead to unintended operation in
converter mode. Conduct a transmission stall test and cool down check to verify proper stator operation.
Refer to the appropriate service manual for the transmission model being serviced.
• Non-bypassed engine coolant thermostats that are not opening properly may cause an overheat condition of
the transmission fluid.
• The converter temperature sensor resistance is available on the Allison DOC Data Monitor grid. Prior to
selecting ’Connect’ in Allison DOC, check the ’Troubleshoot Specific Problem’ box under the “Connection
Options” and then check the ’Sensor, Voltage, Ohms, and Counts Data’ box. Check if converter temperature
sensor resistance is increasing, decreasing, or stationary with fluctuations in fluid temperature. Normal circuit
operation is indicated if sensor resistance decreases as fluid temperature increases, and sensor resistance
increases as fluid temperature decreases.
• Follow transmission overheat troubleshooting in 6–1. GENERAL TROUBLESHOOTING OF
PERFORMANCE COMPLAINTS of CEC5 Troubleshooting Manual TS7870EN for problem: OVERHEATING
INDICATED BY FLUID CONDITION.
Tool Requirements
• Allison DOC
• J-39700 Universal Breakout Box
• J-47275 4th Generation TCM/VCM Breakout Harness
• J-47275-1 4th Generation TCM/VCM Magnetic Overlay
Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

SIL 11-TR-22
July 25, 2022
Page 38 of 40

DTC P274F Transmission Converter Temperature Sensor Over
Temperature Condition (SPN 3823 / FMI 15) (cont'd)
• J-46708 High Impedance Digital Multimeter
DTC Troubleshooting Step Description
Each item number description in this list correlates to the identical number shown in the DTC table "Step" column
and is meant to briefly describe the "Action" column procedures for a particular step in the table. The DTC
troubleshooting step descriptions examine the following:
1. Check for active DTC.
2. Check for DTC P274C
3. Check fluid level .
4. Check for equipment cooling issues by performing idle test.
5. If DTC is still active, review Diagnostic Aids, begin troubleshooting again at Step 1.
Step

Action

Value(s)

Yes

No

1

1.
2.
3.

Install Allison DOC.
Start the engine.
Record snapshot using Allison DOC
showing active or inactive code(s).
4. Review failure records report from snapshot
to determine conditions when DTC occurs.
Is DTC P274F active or inactive in TCM history?

Go to Step 2

System OK.
Clear inactive
DTCs and return
equipment to
service.

2

Is DTC P274C active or inactive in TCM history?

Troubleshoot
DTC P274C

Go to Step 3.

3

1.

With the engine at idle, transmission in
N (Neutral), check the transmission fluid
level using the Oil Level Sensor (OLS) if
equipped or the sight glass.
2. Turn ignition OFF.
3. Add or remove fluid as necessary.
4. Start the engine and recheck fluid level.
5. Duplicate conditions from failure record.
6. Check for active DTC P274F.
Is DTC P274F active?

Go to Step 4.

Go to Step 5

4

NOTE: For complete procedures, steps, and
specifications to conduct a cooling test, refer to
Applications Technical Document, TD165, on
the Allison HUB.

Go to Step 5

Address
equipment
overheating or
cooling system
issue. Go to
Step 5.

Can vehicle idle in range for 30 minutes without
setting active DTC P274F?

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

SIL 11-TR-22
July 25, 2022
Page 39 of 40

DTC P274F Transmission Converter Temperature Sensor Over
Temperature Condition (SPN 3823 / FMI 15) (cont'd)
Step
5

Action
1.
2.

Clear the DTC.
Using Allison DOC, record snapshot of
transmission fluid temperature.
3. Drive the vehicle under normal operating
conditions. Watch for significant change in
retarder TFT sensor.
Did DTC P274F return?

Value(s)

Yes

No

Review
Diagnostic
Aids for this
DTC. Begin the
diagnosis again.
Go to Step 1.

System OK.
Clear inactive
DTCs and
return vehicle
to service.

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

SIL 11-TR-22
July 25, 2022
Page 40 of 40

Appendix C. 9832 Warmup/Brake Hydraulic System Schematic
and Power Flow Diagrams

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

FOLDOUT 1

Foldout 1. 9832 Warmup/Brake Hydraulic System Schematic

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

FOLDOUT 2

Foldout 2. 9832 Brake Power Flow

Copyright © 2022 Allison Transmission, Inc. All Rights Reserved.

FOLDOUT 3

Foldout 3. 9832 Warmup Power Flow