Page 3524 of 5267

6.CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORTTOTHE
(F856) 5-VOLT SUPPLY CIRCUIT INTERNAL TO THE TRANSMISSION
Remove the Transmission Oil Pan. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE/FLUID - STANDARD PROCEDURE)
Disconnect the Governor Pressure Sensor connector internal to the
transmission.
Measure the resistance between the (T54) Transmission Temperature
Sensor Signal circuit and (F856) 5-volt Supply circuit in the Governor
Pressure Sensor connector internal to the transmission.
Is the resistance above 100k ohms?
Ye s>>
Go To 7
No>>
Replace the Transmission Solenoid Assembly per the Ser-
vice Information. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
7.CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT FOR AN OPEN
INTERNAL TO THE TRANSMISSION
Reconnect the Transmission Solenoid Assembly harness connector.
Measure the resistance of the (T54) Transmission Temperature Sensor
Signal circuit between the PCM C2 harness connector and the Gover-
nor Pressure Sensor connector internal to the transmission.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 8
No>>
Replace the Transmission Solenoid Assembly per the Ser-
vice Information. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
Page 3525 of 5267

8.CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN INTERNAL TO THE TRANSMISSION
Measure the resistance of the (F856) 5-volt Supply circuit between PCM
C2 harness connector and the Governor Pressure Sensor connector
internal to the transmission.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Replace the Transmission Solenoid Assembly per the Ser-
vice Information. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
9.CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN INTERNAL TO THE TRANSMISSION
Measure the resistance of the (K900) Sensor Ground circuit between
the PCM C1 harness connector and the Governor Pressure Sensor
connector internal to the transmission.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 10
No>>
Replace the Transmission Solenoid Assembly per the Ser-
vice Information. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
Page 3526 of 5267

10.CHECK THE TRANSMISSION TEMPERATURE SENSOR
TYPICAL VALUES FOR TRANSMISSION TEMPERATURE SENSOR
TEMPERATURE MIN TO MAX OHM RANGE
-40° C (-40° F) 1094 to 1176 ohms
0.0° C (32° F) 1587 to 1672 ohms
25° C (77° F) 1960 to 2040 ohms
70° C (158° F) 2709 to 2860 ohms
0° C (212° F) 3284 to 3500 ohms
120° C (120° F) 3684 to 3950 ohms
150° C (302° F) 4110 to 4450 ohms
Measure the resistance of the Transmission Temperature Sensor between the (T54) Transmission Temperature Sen-
sor Signal circuit and the (K900) Sensor Ground circuit.
Using the chart above, compare the Temperature Sensor temperature to the correlating resistance value.
Is the Temperature Sensor resistance above the maximum specification listedinthechart?
Ye s>>
Replace the Governor Pressure/Transmission Temperature Sensor per the Service Information. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR-
REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Go To 11
Page 3527 of 5267

11 .CHECK THE POWERTRAIN CONTROL MODULE
Reconnect all disconnected connectors.
Ignition on, engine not running.
With the scan tool, erase Engine DTCs.
Turn the ignition off to the lock position.
Disconnect the Governor Pressure Sensor connector internal to the
transmission.
Connect a jumper wire between the (T54) Transmission Temperature
Sensor Signal circuit and the (K900) Sensor Ground circuit in the Trans-
mission Solenoid Assembly harness connector.
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Did the DTC Transmission Oil Temperature Sensor Voltage Too
Low set?
Ye s>>
Go To 12
No>>
Using the schematics as a guide, check the Powertrain
Control Module (PCM) pins, terminals, and connectors for
corrosion, damage, or terminal push out. Pay particular
attention to all power and ground circuits. If no problems
are found, replace and program the PCM per the Service
Information. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/POWERTRAIN CONTROL MODULE
- REMOVAL)
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
12.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention
to the DTC set conditions, such as, VSS, MAP, ECT, and Load
Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched,
or partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken,bent, pushed out, or corroded terminals.
Wiggle the wiring and connectors while checking for any possible open or shorted circuits.
Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 3528 of 5267
P0720-LOW OUTPUT SPEED SENSOR - RPM ABOVE 15 MPH (GAS)
For a complete wiring diagramRefer to Section 8W
Page 3529 of 5267

When Monitored:
Continuously with the ignition on, engine running, and gear selector NOT in park or neutral.
Set Condition:
This DTC will set if the vehicle speed (reported from the CAB module) is above 24 Kmh (15 mph), and the
monitored Output Shaft Speed is below 60 RPM for 2.6 seconds.
Possible Causes
PARK/NEUTRAL DTC PRESENT
(T13) SENSOR GROUND CIRCUIT OPEN
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT OPEN
(T13) SENSOR GROUND CIRCUIT SHORT TO ANOTHER CIRCUIT
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO GROUND
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO ANOTHER CIRCUIT
(T13) SENSOR GROUND CIRCUIT SHORT TO VOLTAGE
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
OUTPUT SPEED SENSOR
POWERTRAIN CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)
Diagnostic Test
1.CHECK IF THE DTC IS CURRENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Record the Freeze Frame data for the reported DTC.
With the scan tool, erase DTCs.
Turn the ignition off to the lock position.
Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.
NOTE: It may be necessary to road test the vehicle to duplicate the originalset conditions.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Ye s>>
Go To 2
No>>
Go To 11
2.CHECK IF A PARK/NEUTRAL DTC IS PRESENT
Is there a Park/Neutral DTC present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom(s). (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - 48RE - DIAGNOSIS AND TESTING)
No>>
Go To 3
Page 3530 of 5267

3.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C2 harness connector.
Disconnect the Output Speed Sensor harness connector.
Measure the resistance of the (T14) Output Speed Sensor Signal circuit
between the PCM C2 harness connector and the Output Speed Sensor
harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 4
No>>
Repair the (T14) Output Speed Sensor Signal circuit for an
open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
4.CHECK THE (T13) SENSOR GROUND CIRCUIT FOR AN OPEN
Measure the resistance of the (T13) Sensor Ground circuit between the
PCM C2 harness connector and the Output Speed Sensor harness con-
nector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the (T13) Sensor Ground circuit for an open.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
Page 3531 of 5267

5.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T14) Output Speed
Sensor Signal circuit.
Is the resistance greater than 100K ohms?
Ye s>>
Go To 6
No>>
Repair the (T14) Output Speed Sensor Signal circuit for a
short to ground.
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)
6.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Measure the resistance between the (T14) Output Speed Sensor Signal
circuit and all other circuits in the PCM C2 harness connector.
Is the resistance greater than 100K ohms between the (T14)
Output Speed Sensor Signal circuit and any other circuit(s) in
the PCM C2 harness connector?
Ye s>>
Go To 7
No>>
Repair the (T14) Output Speed Sensor Signal circuit for a
short to another circuit(s).
Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE - STANDARD PROCEDURE)