Page 2761 of 5267

3.CHECK THE (T52) INPUT SPEED SENSOR SIGNAL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector.
Disconnect the Input Speed Sensor harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller tool #8815 to per-
form diagnosis.
Measure the resistance of the (T52) Input Speed Sensor Signal circuit
between the Input Speed Sensor harness connector and the appropri-
ate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T52) Input Speed Sensor Signal circuit for an
open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 4
4.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR AN OPEN
Measure the resistance of the (T13) Speed Sensor Ground circuit
between the Input Speed Sensor harness connector and the appropri-
ate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for an open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 5
Page 2762 of 5267
5.CHECK THE (T52) INPUT SPEED SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T52) Input Speed
Sensor Signal circuit.
Is the resistance Below 5.0 ohms?
Ye s>>
Repair the (T52) Input Speed Sensor Signal circuit for a
short to ground.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 6
6.CHECK THE (T52) INPUT SPEED SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
Disconnect the Output Speed Sensor harness connector.
Ignition on, engine not running.
With the scan tool under TIPM, actuate the Transmission.
Measure the voltage of the (T52) Input Speed Sensor Signal circuit.
Is the voltage above 0.5 volt?
Ye s>>
Repair the (T52) Input Speed Sensor Signal circuit for a
short to voltage.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 7
Page 2763 of 5267

7.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR A SHORT TO VOLTAGE
With the scan tool under TIPM, actuate the Transmission.
Measure the voltage of the (T13) Speed Sensor Ground circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for a short to
voltage.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1.
No>>
Using the schematics as a guide, check the Powertrain
Control Module (PCM) terminals for corrosion, damage, or
terminal push out. Pay particular attention to all power and
ground circuits. Check for Service Information Tune-ups or
Service Bulletins for any possible causes that may apply. If
no problems are found, replace the PCM per the Service
Information. With the scan tool, perform QUICK LEARN.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
8.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set the DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wiring and connectors while checking for shorted and open circuits.
With the scan tool , check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 2764 of 5267
P0720-OUTPUT SPEED SENSOR CIRCUIT
For a complete wiring diagramRefer to Section 8W.
Page 2765 of 5267

When Monitored:
The transmission gear ratio is monitored continuously while the transmission is in gear.
Set Condition:
If there is an excessive change in the Output RPM in any gear.
Possible Causes
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT OPEN
(T13) SPEED SENSOR GROUND CIRCUIT OPEN
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO GROUND
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
(T13) SPEED SENSOR GROUND 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 - 42RLE - STANDARD PROCEDURE)
Theory of Operation
The transmission system uses two speed sensors, one to measure input RPM and one to measure output RPM.
These inputs are essential for proper transmission operation. Therefore, the integrity of this data is verified through
system checks.
Diagnostic Test
1.CHECK IF THE DTC IS CURRENT
Start the engine in park.
Raise the drive wheels off of the ground.
WARNING: Properly support the vehicle.
Firmly apply the brakes and place the transmission selector in drive.
WARNING: Be sure to keep hands and feet clear of rotating wheels.
Release the brakes and allow the drive wheels to spin freely.
NOTE: The drive wheels must be turning at this point.
With the scan tool, read the Output RPM
Is the Output RPM below 100?
Ye s>>
Go To 2
No>>
Go To 8
2.CHECK THE PCM AND WIRING USING THE TRANSMISSION SIMULATOR
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Install the Transmission Simulator,Miller tool #8333 and the ElectronicTransmission Adapter kit.
Ignition on, engine not running.
With the Transmission Simulator, set the
Input/Output Speedswitch toONand the rotary switch to the3000/
1250
position.
Page 2766 of 5267

With the scan tool , read the Input and Output RPM.
Does the Input RPM read 3000 and the Output RPM read 1250 (within 50 RPM)?
Ye s>>
Replace the Output Speed Sensor per the Service Information.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 3
3.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector.
Disconnect the Output Speed Sensor harness connector.
NOTE: Check connectors - Clean/repair as necessary.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller tool #8815 to per-
form diagnosis.
Measure the resistance of the (T14) Output Speed Sensor Signal circuit
between the Output Speed Sensor harness connector and the appropri-
ate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T14) Output Speed Sensor Signal circuit for an
open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 4
Page 2767 of 5267
4.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR AN OPEN
Measure the resistance of the Speed Sensor Ground circuit between
the Output Speed Sensor harness connector and the appropriate termi-
nal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for an open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 5
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 below 5.0 ohms?
Ye s>>
Repair the (T14) Output Speed Sensor Signal circuit for a
short to ground.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 6
Page 2768 of 5267

6.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
Ignition on, engine not running.
With the scan tool under TIPM, actuate the Transmission.
Measure the voltage of the (T14) Output Speed Sensor Signal circuit.
Is the voltage above 0.5 volt?
Ye s>>
Repair the (T14) Output Speed Sensor Signal circuit for a
short to voltage.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 7
7.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR A SHORT TO VOLTAGE
With the scan tool under TIPM, actuate the Transmission.
Measure the voltage of the (T13) Speed Sensor Ground circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for a short to
voltage.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Using the schematics as a guide, check the Powertrain
Control Module (PCM) terminals for corrosion, damage, or
terminal push out. Pay particular attention to all power and
ground circuits. Check for Service Information Tune-ups or
Service Bulletins for any possible causes that may apply. If
no problems are found, replace the PCM per the Service
Information. With the scan tool, perform QUICK LEARN.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
8.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set the DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wiring and connectors while checking for shorted and open circuits.
With the scan tool , check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .