When Monitored:
Continuously while driving in a forward gear.
Set Condition:
The PCM continuously monitors Actual Line Pressure. If the Actual Line Pressure reading is greater than the
highest Desired Line Pressure ever used in the current gear, while the Pressure Control Solenoid duty cycle is
at or near its maximum value (which should result in minimum line pressure), the DTC will set.
Possible Causes
(F856) 5-VOLT SUPPLY CIRCUIT OPEN
LINE PRESSURE SENSOR CONNECTION
(T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT OPEN
(F856) 5-VOLT SUPPLY CIRCUIT SHORT TO GROUND
(T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION CONTROL OUTPUT CIRCUIT
LINE PRESSURE SENSOR
STUCK OR STICKING MAIN REGULATOR VALVE
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 measured by the Line Pressure Sensor (LPS) and regulationis achieved by changing the duty
cycle of the Pressure Control Solenoid (PCS) controlled by the Transmission Control System. (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 both the engine and transmission.
The Transmission Control System calculates torque input to the transmission and uses it as the primary input to the
desired line pressure calculation. This is called Torque Based Line Pressure. In addition, the line pressure is set to
a preset level 827 or 931 kPa (120 or 135 psi) during shifts and in Park and Neutral to ensure consistent shift
quality. The desired line pressure is continuously being compared to the actual line pressure. If the actual line pres-
sure is consistently higher than the highest desired line pressure ever used in the current gear, the line pressure
high DTC P0869 will set.
Diagnostic Test
1.CHECKFORRELATEDDTC’S
With the scan tool, check for other Transmission DTC’s
Are there any line pressure sensor or transmission relay output DTCs present also?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
2.CHECK IF THE DTC IS CURRENT
With the scan tool, check the STARTS SINCE SET counter for P0869.
Is the STARTS SINCE SET COUNTER 2 or less?
Ye s>>
Go To 3
No>>
Go To 9
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.
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.
Using the Transmission Simulator, set the rotary 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>>
Go To 4
No>>
Go To 5
4.CHECK THE LINE PRESSURE SENSOR CALIBRATION
Turn the ignition off to the lock position.
Disconnect the Transmission Simulator, Miller tool #8333 and the Electronic Transmission Adapter kit and reconnect
all previously disconnected connectors.
Install the Line Pressure Gauge, Miller tool #C-3293, 0 to 2000 kPa or 0 to 300 psi in the L/R pressure port.
Start the engine in park.
Monitor the Line Pressure readings on the scan tool and the pressure gauge.
Compare the Line Pressure readings between the scan tool and the pressure gauge.
Is the pressure gauge reading within 34 kPa or 5 psi of the scan tool reading?
Ye s>>
Repair the internal transmission and inspect the Transmission Oil Pump per the Service Information and
replace if necessary. If no problem is found, replace the Pressure ControlSolenoid.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
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 THE (T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the Transmission Simulator, Miller tool #8333.
Disconnect the Powertrain Control Module C4 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 (T118) Pressure Control Solenoid Control
circuit between the Line Pressure Sensor/Variable Force Solenoid
Assembly harness connector and the appropriate terminal of Miller tool
#8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T118) Pressure Control Solenoid Control 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
6.CHECK THE (T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T118) Pressure Con-
trol Solenoid Control circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T118) Pressure Control Solenoid Control 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 7
7.CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN
Measure the resistance of the (F856) 5-volt Supply circuit between the
Line Pressure Sensor/Variable Force Solenoid Assembly harness con-
nector and the appropriate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (F856) 5-volt Supply circuit for an open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 8
8.CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND
Disconnect the PCM C1 harness connector.
Disconnect the Line Pressure Sensor/Variable Force Solenoid Assembly
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 between ground and the (F856) 5-volt Supply
circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (F856) 5-volt Supply circuit for a short to ground.
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)
P0932-LINE PRESSURE SENSOR CIRCUIT
For a complete wiring diagramRefer to Section 8W
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 .
P0934-LINE PRESSURE SENSOR CIRCUIT LOW
For a complete wiring diagramRefer to Section 8W.