When Monitored:
In any forward gear with engine speed above 1000 RPM, shortly after a shift and every minute thereafter.
Set Condition:
After a shift into a forward gear, with engine speed greater than 1000 RPM, the PCM momentarily turns on
element pressure to the clutch circuits that don’t have pressure to verifythat the correct pressure switch
closes. If the pressure switch does not close 2 times the DTC sets
Possible Causes
LOSS OF PRIME P0944 PRESENT
(T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
(T47) 2/4 PRESSURE SWITCH SENSE CIRCUIT OPEN
(T47) 2/4 PRESSURE SWITCH CIRCUIT SHORT TO GROUND
(T47) 2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
TRANSMISSION SOLENOID/PRESSURE SWITCH ASSEMBLY
INTERNAL TRANSMISSION
POWERTRAIN CONTROL MODULE
Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
Theory of Operation
Pressure switches are normally off or open (no pressure applied) and read high (+12 volts). When an element is
applied, the corresponding pressure switch closes to ground (0 volts) or turns on. The controller tests the OD and
24 pressure switches when they are off (when the corresponding friction element is not applied) by briefly applying
the OD and 24 elements which will cause the corresponding pressure switch to close. The test verifies that the
switches are operational and that the switch will close when the corresponding element is applied. If a switch fails
to respond, it is re-tested. The MIL illuminates and the transmission system defaults to Limp-in mode.
Diagnostic Test
1.CHECKING FOR LOSS OF PRIME DTC
With the scan tool, check for other Transmission DTCs.
Is the DTC P0944 present also?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK FOR RELATED TRANSMISSION DTCS
With the scan tool, read Transmission DTCs.
Are any of the DTCs P0732, P0734 and/or P0846 present also?
Ye s>>
Replace the Transmission Solenoid/Pressure Switch Assembly 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 TO SEE IF DTC P0845 IS CURRENT
With the scan tool, view DTCs.
Is the status Active for this DTC or is the STARTS SINCE SET counter 2 or less?
Ye s>>
Go To 4
No>>
Go To 9
4.PCM AND WIRING
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, turn the Pressure Switch selector switchto2/4.
With the scan tool, monitor the UD Pressure Switch state while pressing thePressure Switch Test button on the
Transmission Simulator.
Wiggle the wires leading to the PCM while pressing and holding the PressureSwitch Test button.
Did the 2/4 Pressure Switch state change to closed and remain closed while wiggling the wires?
Ye s>>
Disassemble and inspect the Valve Body per the Service Information and repair or replace as neces-
sary. If no problems are found in the Valve Body, replace the Transmission Solenoid/Pressure Switch
Assembly.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 5
5.(T47) 2/4 PRESSURE SWITCH SENSE CIRCUIT OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly har-
ness 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 (T47) 2/4 Pressure Switch Sense circuit
between the Transmission Solenoid/Pressure Switch Assembly harness
connector and the appropriate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T47) 2/4 Pressure Switch Sense circuit for an
open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 6
8.TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
With the scan tool under TIPM, actuate the Transmission.
Using a 12-volt test light connected to ground, check (T16) Transmis-
sion Control Relay Output circuit in the Transmission Solenoid/Pressure
Switch Assembly harness connector.
NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.
Does the test light illuminate brightly?
Ye s>>
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. 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/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Repair the Transmission Control Relay Output circuit for an
open or high resistance. If the fuse is open make sure to
check for a short to ground.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
9.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 wires 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.
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 .
2.CHECK FOR LOSS OF PRIME DTC
With the scan tool, check for other Transmission DTCs.
Is the DTC P0944 present also?
Ye s>>
Refer to the Transmission category and perform the appropriate diagnostic procedure.
No>>
Go To 3
3.CHECK TO SEE IF P0846 IS CURRENT
With the scan tool, view DTCs.
Is the status Active for this DTC or is the STARTS SINCE SET counter 2 or less?
Ye s>>
Go To 4
No>>
Go To 8
4.PCM AND WIRING
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, turn the Pressure Switch selector to 2/4.
With the scan tool , monitor the 2/4 Pressure Switch state while pressing the Pressure Switch Test button on the
Transmission Simulator.
Did the 2/4 Pressure Switch state change?
Ye s>>
Replace the Transmission Solenoid/Pressure Switch Assembly per the Service Information.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 5
7.(T47) 2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
Ignition on, engine not running.
With the scan tool under TIPM, actuate the Transmission.
Measure the voltage of the (T47) 2/4 Pressure Switch Sense circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T47) 2/4 PressureSwitch Sense 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. 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/AU-
TOMATIC - 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 wires 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.
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 .
2.CHECK IF THE DTC IS CURRENT
With the scan tool, check the STARTS SINCE SET counter for P0868.
NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET COUNTER 2 or less?
Ye s>>
Go To 3
No>>
Go To 10
3.CHECK THE PCM AND WIRING
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.
On the Transmission Simulator select the
OFFposition of theInput/Output Speedswitch.
Ignition on, engine not running.
With the scan tool, monitor the Line Pressure during the following steps.
Using the Transmission Simulator, set the rotary knob to each of the 3 line pressure positions.
NOTE: All three scan tool Line Pressure readings should be steady and ± 14 kPa or 2.0 psi of the reading
specified on the Transmission Simulator.
Did the Line Pressure read within ± 14 kPa or 2.0 psi in all three positions?
Ye s>>
Go To 4
No>>
Go To 6
4.CHECK THE LINE PRESSURE SENSOR
Turn the ignition off to the lock position.
Disconnect the Transmission Simulator, Miller tool #8333 and reconnect all previously disconnected connectors.
Install a Pressure Gauge, 0 to 2000 kPa or 0 to 300 psi to the L/R test port.
Start the engine in park.
Monitor the line pressure readings of both the scan tool and the pressure gauge and compare the two readings.
Is the line pressure gauge reading within 34 kPa or 5 psi of the scan tool reading?
Ye s>>
Go To 5
No>>
Replace the Line Pressure Sensor per the Service Information.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
5.CHECK FOR A PLUGGED TRANSMISSION OIL FILTER
Turn the ignition off to the lock position.
Remove and inspect the Transmission Oil Pan for excessive debris per the Service Information.
Remove and inspect the Transmission Oil Filter per the Service Information.
Does the Oil Pan contain excessive debris and/or is the Transmission Oil Filter plugged?
Ye s>>
Repair as necessary. If the Transmission Oil Filter is plugged or there is excessive debris, refer to the
Service Information for the proper Hydraulic repair procedure.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Repair internal transmission and inspect the Transmission Oil Pump per the Service Information and
replace if necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
6.CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
Disconnect the Transmission Simulator, Miller tool #8333 and the Elec-
tronic Transmission Adapter kit.
Reconnect all previously disconnected connectors except the Line Pres-
sure Sensor/Variable Force Solenoid Assembly harness connector.
Ignition on, engine not running.
Measure the voltage of the (F856) 5-volt Supply circuit.
Is the voltage above 5.5 volts?
Ye s>>
Repair the (F856) 5-volt Supply 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
9.CHECK THE (T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT FOR A SHORT TO ANOTHER
CIRCUIT
Turn the ignition off to the lock position.
Disconnect the Line Pressure Sensor/Variable Force Solenoid Assembly
harness connector.
Disconnect all PCM harness connectors.
Measure the resistance between the (T118) Pressure Control Solenoid
Control circuit and all other circuits in the Line Pressure Sensor/Variable
Force Solenoid Assembly harness connector.
Is the resistance below 5.0 ohms between the (T118) Pressure
Control Solenoid Control circuit and any other circuit(s) in the
Line Pressure Sensor/Variable Force Solenoid Assembly har-
ness connector?
Ye s>>
Repair the (T118) Pressure Control Solenoid Control circuit
for a short to another circuit(s).
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. 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)
10.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires 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.
Where 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 .