3.CHECK FOR INTERMITTENT OPERATION
The conditions to set this DTC are not current at this time.
Check the gearshift linkage adjustment.
Gear ratio DTC’s can be set by problems in the Input and Output Speed Sensor circuits. If the vehicle passes the
Clutch Test and still sets a Gear Ratio DTC, check the Speed Sensors for proper operation.
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.
Check the wiring and connectors for the Speed Sensors for a good connection, then perform a wiggle test using the
Transmission Simulator.
This DTC can also be set under extreme temperature conditions, this is usually caused by an internal problem.
Verify if the problem is only experienced under extreme hot or cold conditions.
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 .
4.CHECKFORRELATEDPRESSURESWITCHDTCS
With the scan tool, read Transmission DTC’s.
Are the DTC’s P0870 and/or P0871 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>>
Repair internal Transmission per the Service Information. Check all of the components related to the
O/D and 2/4 clutches. Inspect the Oil Pump and repair or replace as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
P0736-GEAR RATIO ERROR IN REVERSE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
The Transmission gear ratio is monitored continuously while the transmission is in gear.
Set Condition:
If the ratio of the Input RPM to the Output RPM does not match the current gearratio when compared to the
known gear ratio.
Possible Causes
RELATED TRANSMISSION DTCS PRESENT
INTERMITTENT GEAR RATIO ERRORS
INTERNAL TRANSMISSION
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
data checks. When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding gear ratio
error trouble code is set. The transmission will go into Limp-in mode afterfour gear ratio error events occur in a
given driving cycle.
Diagnostic Test
1.DETERMINING IF RELATED TRANSMISSION DTCS ARE PRESENT
With the scan tool, read Transmission DTCs.
If any of these DTCs are present, perform their respective tests first.
Are there any Loss of Prime, Line Pressure Sensor and/or Speed Sensor DTCs present?
Ye s>>
Refer to appropriate diagnostic procedure in the Transmission category.If any of these DTCs are
present, they will cause a gear ratio error. Perform the test for Loss of Primefirstifitispresent.
No>>
Go To 2
2.CHECK TO SEE IF P0731 IS CURRENT
With the scan tool, perform the Reverse gear clutch test. Follow the instructions on the scan tool.
Increase the throttle angle or TPS Degree to 30° for no more than a few seconds.
CAUTION: Do not overheat the transmission.
Did the Clutch Test pass, Input Speed remain at zero?
Ye s>>
Go To 3
No>>
Repair internal Transmission per the Service Information. Check all of the components related to the
Reverse and LR clutches. Inspect the Oil Pump and repair or replace as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
When Monitored:
Continuously while driving in a forward gear.
Set Condition:
The PCM continuously monitors Actual Line Pressure and compares it to DesiredLinePressure.IftheActual
Line Pressure is more than 10 psi below Desired Line Pressure, this DTC willset.
Possible Causes
CHECK FOR RELATED DTC’S
LOW FLUID LEVEL
(F856) 5-VOLT SUPPLY CIRCUIT OPEN
(F856) 5-VOLT SUPPLY CIRCUIT SHORT TO GROUND
(F856) 5-VOLT SUPPLY CIRCUIT SHORT TO VOLTAGE
(T118) PRESSURE CONTROL SOLENOID CONTROL CIRCUIT SHORT TO ANOTHER CIRCUIT
INTERNAL TRANSMISSION
LINE PRESSURE SENSOR
CRACKED, PLUGGED, OR MIS-INSTALLED PRIMARY OIL FILTER
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 lower than the target while driving, the line pressure low DTC P0868 will set.
Diagnostic Test
1.CHECKFORRELATEDDTCS
With the scan tool, check for other transmission DTCs
Is the DTC P0932 present also?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom.
No>>
Go To 2
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
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)
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 .
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
2.INTERMITTENT OPERATION
The conditions necessary to set this DTC are not present at this time.
Test drive the vehicle. Allow the Transmission to shift through all gears and ranges.
Was a delayed engagement and/or a no drive condition present during the testdrive?
Ye s>>
Go To 4
No>>
Go To 3
3.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 wiring while checking for shorted and open circuits.
With the scan tool, check the EVENT DATAto help identify the conditions in 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 .
4.SHIFT LEVER POSITION TEST
With the scan tool, perform a Shift Lever Position test. Follow the instructions on the screen.
Did the Shift Lever Position Test pass?
Ye s>>
Go To 5
No>>
Perform the diagnostic procedure for P0706-CHECK SHIFTER SIGNAL.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
5.CHECK FOR PLUGGED TRANSMISSION FILTER
Remove the Transmission Pan and inspect the Transmission Fluid and Transmission Filter per the Service Informa-
tion.
Does the Transmission Oil Pan contain excessive debris and/or is the Oil Filter plugged?
Ye s>>
Repair the cause of the plugged Transmission Filter. Refer to the Service Information for the proper
repair procedure.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Replace the Transmission Oil Pump per the Service Information.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)