2.(T9) OD PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly har-
ness connector.
Ignition on, engine not running.
With the scan tool under TIPM, actuate the Transmission.
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 Special Tool #8815
to perform diagnosis.
Measure the voltage of the (T9) OD Pressure Switch Sense circuit.
Is the voltage above 0.5 volt?
Ye s>>
Repair the (T9) OD Pressure Switch 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>>
Go To 3
3.(T47) 2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
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 volt?
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>>
Go To 4
P0897-TRANSMISSION FLUID DETERIORATED
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Each transition from full EMCC to partial EMCC for A/C bump prevention.
Set Condition:
DTC set if 20 occurrences of a turbine acceleration sum. Fault Set Time: 20 transitions from full EMCC to
partial EMCC. Transmission will not use partial EMCC. Established for A/Cbump prevention.
Possible Causes
WORN OUT/ BURNT TRANSAXLE FLUID
Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
Theory of Operation
To prevent a bump due to A/C clutch engagement, a temporary torque converter partial EMCC condition is estab-
lished prior to A/C clutch engagement. A message is received over the bus indicating that A/C clutch engagement
is imminent. Partial EMCC is then established and a reply message,
OK to engage A/C clutchis sent via the bus.
Partial EMCC will be held for 450 ms before returning to full EMCC. During the transition from full to partial EMCC,
a turbine acceleration sum is calculated, if this value exceeds a threshold value for several transitions, degraded
transmission fluid is indicated.
Diagnostic Test
1.WORN OUT/ BURNT TRANSMISSION FLUID
Turn the ignition off to the lock position.
Flush the Transmission Oil Cooler and lines, replace the Transmission OilFilter, refill with new Transmission Fluid,
start the engine, and adjust the fluid per the Service Information.
NOTE: The Transmission Cooler must be flushed before proceeding.
Allow the engine to idle for 10 minutes, in Park.
Turn the ignition off to the lock position.
Again, flush the Transmission Oil Cooler and lines, replace the Transmission Oil Filter, refill with new Transmission
Fluid, start the engine, and adjust the fluid per the Service Information.
With the scan tool, perform a Battery Disconnect.
NOTE: The Battery Disconnect must be done to re-enable EMCC during an A/C Clutch engagement.
NOTE: The vehicle may exhibit intermittent shudder during the first few hundred miles. The new Transmis-
sion Fluid will gradually penetrate the Torque Convertor Clutch frictionmaterial and the shudder should
disappear.
Erase the DTC and return the vehicle to the customer.
Did the DTC reset and/or does the vehicle still shudder after a few thousandmiles?
Ye s>>
Replace the Torque Converter per the Service Information.
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 .
When Monitored:
Continuously with the ignition on, engine running, with the transmissionin gear.
Set Condition:
The PCM continuously monitors Actual Line Pressure and compares it to DesiredLinePressure.IftheActual
Line Pressure reading is more than 172.4 kPa (25 psi) higher than the Desired Line Pressure, but is less than
the highest Line Pressure ever used in the current gear, the DTC sets.
Possible Causes
RELATED DTC’S PRESENT
LINE PRESSURE CONNECTOR AND WIRING
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
Line pressure is electronically controlled by the Transmission Control System and is measured by the Line Pressure
Sensor (LPS). The desired line pressure is continuously being compared tothe actual line pressure and is regulated
by electronically changing the dutycycle of the Pressure Control Solenoid (PCS). (5% duty cycle = solenoid off =
max line pressure, 62% duty cycle =solenoid on = min line pressure).
The Transmission Control System calculates the desired line pressure based on inputs from the transmission and
engine. A calculated torque input to the transmission is used as the primary input of the desired line pressure cal-
culation and is called Torque Based Line Pressure. In addition, the line pressure is set to a preset level 827 to 931
kPa (120 to 135 psi) during shifts and in Park and Neutral to ensure consistent shift quality.
Diagnostic Test
1.DETERMINING IF RELATED DTCS ARE PRESENT
With the scan tool, check for other transmission DTCs.
Are there any other line pressure related DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom. Perform the test for P0934
and/or P0935 first if present.
No>>
Go To 2
2.COMPARE ACTUAL LINE PRESSURE TO DESIRED LINE PRESSURE
CAUTION: Apply Parking Brake
Start the engine.
CAUTION: Firmly apply the brakes.
With the scan tool, monitor the Line Pressure, Desired Line Pressure and the TPS degrees.
While firmly applying the brakes, place the shifter in reverse, then slowly press the accelerator pedal to a TPS
degree of 15°.
Compare the Line Pressure reading to the Desired Line Pressure reading on the scan tool.
Does the Line Pressure stay within ± 34 kPa or 5 psi of the Desired Line Pressure?
No>>
Go To 3
Ye s>>
Go To 5
3.CHECK LINE PRESSURE CONNECTOR AND WIRING
Ignition on, engine not running.
With the scan tool, monitor the Line Pressure Sensor voltage while wiggling the wiring harness and connectors
pertaining to the Line Pressure Sensor/Variable Force Solenoid Assembly.
Did the voltage remain steady while wiggling the wiring harness and connectors?
Ye s>>
Go To 4
No>>
Disconnect and properly reconnect the Line Pressure Sensor/Variable Force Solenoid Assembly con-
nector. Inspect terminals and repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
4.CHECK 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.
With the Transmission Simulator select the
OFFposition on theInput/Output Speedswitch.
Ignition on, engine not running.
With the scan tool, monitor the Line Pressure during the following step.
With the Transmission Simulator, turn the selector switch 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>>
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)
No>>
Repair internal transmission and inspect the oil pump per the Service information and replace if neces-
sary. If no problems are found, replace the Line Pressure Sensor/VariableForce Solenoid Assembly —
possible cause is the Pressure Control Solenoid is stuck.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
5.CHECK 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 .
When Monitored:
Continuously with the ignition on and engine running.
Set Condition:
This DTC will set when the monitored Line Pressure Sensor voltage is less than or equal to 0.35 volts for 0.18
seconds.
Possible Causes
(F856) 5-VOLT SUPPLY CIRCUIT OPEN
(F856) 5-VOLT SUPPLY CIRCUIT SHORT TO GROUND
(T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO GROUND
LINE PRESSURE SENSOR
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
Line pressure is electronically controlled by the Transmission Control System and is measured by the Line Pressure
Sensor (LPS). The desired line pressure is continuously being compared tothe actual line pressure and is regulated
by electronically changing the dutycycle of the Pressure Control Solenoid (PCS). (5% duty cycle = solenoid off =
max line pressure, 62% duty cycle =solenoid on = min line pressure).
The Transmission Control System calculates the desired line pressure based on inputs from the transmission and
engine. A calculated torque input to the transmission is used as the primary input of the desired line pressure cal-
culation and is called Torque Based Line Pressure. In addition, the line pressure is set to a preset level 827 to 931
kPa (120 to 135 PSI) during shifts and in Park and Neutral to ensure consistent shift quality.
The monitored Line Pressure Sensor voltage should always be between 0.35 and 4.75 volts. Any monitored volt-
ages outside these parameters indicate an Line Pressure Sensor or wiring problem and will cause either DTC
P0934 or P0935 to set.
Diagnostic Test
1.CHECK IF DTC IS CURRENT
With the scan tool, check the STARTS SINCE SET counter for P0934.
NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET counter 2 or less?
Ye s>>
Go To 2
No>>
Go To 6
2.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.
Ignition on, engine not running.
With the scan tool, under Transmission Sensors, monitor the Line Pressure.
Using the Transmission Simulator, set the rotary switch to each of the 3 line pressure positions.
When Monitored:
Continuously with ignition on and engine running.
Set Condition:
This DTC will set if the monitored Line Pressure Sensor voltage is greater than or equal to 4.75 volts for the
period of 0.18 seconds
Possible Causes
(T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
(T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
LINE PRESSURE SENSOR
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
Line pressure is electronically controlled by the Transmission Control System and is measured by the Line Pressure
Sensor (LPS). The desired line pressure is continuously being compared tothe actual line pressure and is regulated
by electronically changing the dutycycle of the Pressure Control Solenoid (PCS). (5% duty cycle = solenoid off =
max line pressure, 62% duty cycle =solenoid on = min line pressure).
The Transmission Control System calculates the desired line pressure based on inputs from the transmission and
engine. A calculated torque input to the transmission is used as the primary input of the desired line pressure cal-
culation and is called Torque Based Line Pressure. In addition, the line pressure is set to a preset level 827 to 931
kPa (120 to 135 PSI) during shifts and in Park and Neutral to ensure consistent shift quality.
The monitored Line Pressure Sensor voltage should always be between 0.35 and 4.75 volts. Any monitored volt-
ages outside these parameters indicate an Line Pressure Sensor or wiring problem and will cause either DTC
P0934 or P0935 to set.
Diagnostic Test
1.CHECK TO SEE IF DTC IS CURRENT
With the scan tool, Check the STARTS SINCE SET counter for P0935.
NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET counter 2 or less?
Ye s>>
Go To 2
No>>
Go To 6
2.CHECK THE PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Starter Relay.
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 scan tool, monitor the Line Pressure.
Using the Transmission Simulator, set the rotary switch to each of the 3 line pressure positions.
4.CHECK THE (T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN
Disconnect the PCM C4 harness connector and connect Miller tool
#8815.
Measure the resistance of the (T38) Line Pressure Sensor Signal circuit
from the Line Pressure Sensor/Variable Force Solenoid Assembly har-
ness connector to the appropriate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T38) Line Pressure 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 5
5.CHECK THE (T38) LINE PRESSURE 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 (T38) Line Pressure Sensor Signal circuit.
Is the voltage above 5.5 volts?
Ye s>>
Repair the (T38) Line Pressure 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>>
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)
P0944-LOSS OF HYDRAULIC PUMP PRIME
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Every 350 msec
Set Condition:
If the transmission begins to slip in any forward gear, and the pressure switch or switches that should be
closed for a given gear are open, a loss of prime test begins. All available elements (in 1st gear LR, 2/4 and
OD, in 2nd, 3rd, and 4th gear 2/4 and OD) are turned on by the PCM to see if pump prime exists. The code
is set if none of the pressure switches respond. The PCM will continue to runthe loss of prime test until pump
pressure returns. The vehicle will not move or the transmission will slip.Normal operation will continue if pump
prime returns.
Possible Causes
LOW TRANSMISSION FLUID LEVEL
SHIFT LEVER POSITION
PLUGGED TRANSMISSION FILTER
TRANSMISSION OIL PUMP
Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
Theory of Operation
The Loss of Prime Test is used to prevent transmission defaults and erroneous fault codes during temporary loss of
pump prime that may occur with low transmission fluid under severe brakingconditions, start-up, etc. and to point
towards more subtle problems such as a plugged or ruptured oil filter. The Loss of Prime fault is set by a loss of
hydraulic pressure in the transmission system. This condition, if sustained, will result in the vehicle being unable to
move.
Diagnostic Test
1.CHECK TO SEE IF DTC P0944 IS CURRENT
Place the gear selector in park.
Start the engine.
NOTE: The Transmission Temperature must be at least 43° C (110° F) before performing the following steps.
The Transmission must be at operating temperature prior to checking pressure. Cold transmission fluid will result in
higher pressure readings.
Place the Transmission in Reverse.
With the scan tool, observe the Transmission Pressure Switch states.
Are any of the Pressure Switches closed?
Ye s>>
Go To 2
No>>
Go To 4