3.CHECK TO SEE IF DTC P1776 IS CURRENT
With the scan tool, check the STARTS SINCE SET counter for P1776.
NOTE: This counter only applies to the last DTC set.
Is the status Active or is the STARTS SINCE SET counter 2 or less for this DTC?
Ye s>>
Go To 4
No>>
Go To 9
4.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, turn the Pressure Switch selector switchtoL/R.
With the scan tool, monitor the L/R Pressure Switch State while pressing the Pressure Switch Test button.
Did the Pressure Switch state change from open to closed when the test button was pressed?
Ye s>>
Go To 5
No>>
Go To 6
5.CHECK THE SOLENOID SWITCH VALVE FOR STICKING
Remove the transmission oil pan and Valve body and inspect the Solenoid Switch Valve for sticking in its bore,
repair or replace as necessary.
NOTE: This DTC may be caused by debris lodged in the Transmission Solenoid Switch Valve bore. If debris
is found, clean the valve body and reassemble the transmission per the Service Information.
With the scan tool, record the DTC EVENT DATA for P1776 and erase DTCs.
Reassemble the transmission and test drive the vehicle. Try to duplicate the original set conditions using the DTC
EVENT DATA recorded earlier.
With the scan tool, check Transmission DTCs.
Did the DTC P1776 reset?
Ye s>>
Replace the Transmission Solenoid Assembly 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
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
8.CHECK THE (T50) L/R PRESSURE SWITCH SENSE 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 (T50) L/R Pressure Switch Sense circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T50) L/R 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. 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/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
9.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Test Drive the vehicle and verify if the transmission is launching in 2nd gear and/or there is no TCC engagement.
With the scan tool, check the EVENT DATAto help identify the conditions in which the DTC was set.
Check for any Service Information Tune-ups or Service Bulletins for possible causes that may apply.
Are there 2nd gear launches and/or no TCC engagement?
Ye s>>
Disassemble and inspect the Valve Body per the Service Information Inspect the Solenoid Switch Valve
for sticking in its bore and repair or replace 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:
Every 7msec after a controller reset with transmission in neutral.
Set Condition:
After a PCM reset in neutral and Input and Output sensor ratio equals 2.50 to1.0 ± 50.0 RPM.
Possible Causes
SPEED SENSOR GROUND CIRCUIT OPEN
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
The input and output speed sensors use a common ground circuit. The loss of this common ground results in the
input signal being sensed for both. After a reset in neutral, and after observing a specific ratio, the Speed Check
Fault Counter will increment. Because the speed sensors and the thermistor share the same ground circuit, this
DTC may indicate a loss of the common speed sensor ground. In some cases thisfault will cause a Gear Ratio
Error DTC to be set.
Diagnostic Test
1.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 8333-1A.
Ignition on, engine not running.
With the Transmission Simulator, set the
Input/Output Speedswitch toONand the rotary switch to the3000/
1250
position.
With the scan tool, monitor the Input and Output Speed Sensor readings.
Does the Input Speed read 3000 RPM and the Output Speed read 1250 RPM, ± 50 RPM?
Ye s>>
Go To 2
No>>
Go To 3
P1797-MANUAL SHIFT OVERHEAT
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Continuously with engine running.
Set Condition:
If the Engine Temperature exceeds 123° C (255° F) or the Transmission Temperature exceeds 135° C (275° F)
while in AutoStick
mode. Note: Aggressive driving or driving in low for extended periods of time will set this
DTC.
Possible Causes
MANUAL SHIFT OVERHEAT
Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
Theory of Operation
The major cause of heat build up in the transmission is torque converter slip.WiththetransmissionintheAuto-
Stick
mode, the torque converter can slip during aggressive driving or heavy loading conditions such as trailer
towing or driving up steep grades. In the non AutoStick
mode, internal controller logic prevents the transmission
from overheating by managing the shift and EMCC schedule. In the AutoStick
mode, when the transmission or
engine temperature approaches an overheat condition, the manual shift overheat DTC sets and the AutoStick
mode is temporarily suspended until the temperature returns to normal.
Diagnostic Test
1.MANUAL SHIFT OVERHEAT
This is an informational DTC only.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Check the engine and transmission cooling system for proper operation.
Check the Radiator Cooling Fan operation.
Check the Transmission Cooling operation.
Check the Transmission Fluid Level per the Service Information to verify that it is not overfilled.
NOTE: Aggressive driving or driving in low for extended periods of time will set this DTC.
If there are no possible causes remaining, view repair.
Repair
If the Transmission Fluid is low, repair any Transmission Fluid leak as necessary and adjust the Trans-
mission Fluid Level per the Service Information. Refer to Service Information for the related symptoms
and repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
STANDARD PROCEDURE
PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE - 42RLE
For a complete wiring diagramRefer to Section 8W.
1.
Perform the following steps prior to any diagnostic procedure:
Many transmission symptoms can be caused by a low fluid level. If the fluid level is low, locate and repair any
leaks and fill the transmission to the proper fluid level. Refer to the Service Information for the proper repair
and fluid fill procedures.
Testing should only be performed with the battery fully charged to avoid false diagnosis.
With the scan tool, read Engine (PCM) DTCs. If Engine DTCs are present, refer to the Driveability Category
and perform to the appropriate diagnostic procedure(s) before proceeding.
With the scan tool, read Transmission (TCM) DTCs. Record all Stored, Active, and Pending DTC information.
Diagnose any Pending DTC as a matured DTC.
With the scan tool, read DTC EVENT DATA.Use this data to identify the conditions in which the DTC was set.
Note: Performing a Battery Disconnect will clear all DTC EVENT DATA and reset all learned Transmis-
sion values to the controllers default values, which may temporarily result in erratic shift schedules.
With the scan tool, perform the Shift Lever Position Test. If the test does not pass, refer to the diagnostic
procedure for P0706-Check Shifter Signal.
For Gear Ratio Error DTCs, use the scan tool to read and record the Clutch Volume Index (CVI) information.
Use the wiring diagram as a guide, inspect the wiring and connectors related to this circuit and repair as nec-
essary.
Refer to the When Monitored and Set Conditions for this DTC. DTCs can set at ignition on, at start up, driving
under specific conditions, and after controller diagnostic monitors haverun.
Refer to applicable Technical Service Bulletins (TSBs) for controller software update information. Some condi-
tions can be corrected by upgrading the Engine (PCM) or Transmission (TCM)controller software.
Check for any Service Information Tune-ups or Service Bulletins for any possible causes that may apply.
Were there any repairs made that fixed the vehicle?
Ye s>>
Testing complete.
Perform 42RLE VERIFICATION TEST - VER1(Referto21-TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 42RLE - STANDARD PROCEDURE)
No>>
Refer to the Transmission category and perform the appropriate diagnostic procedure(s). (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - DIAGNOSIS AND TESTING)
42RLE TRANSMISSION VERIFICATION TEST - VER 1
1.
Perform the following after completion of a diagnostic repair:
Note: After completion of the Transmission Verification Test, the Powertrain Verification Test must be
performed. Refer to the Engine Category.
Reconnect any disconnected components.
With the scan tool, erase all Transmission and Engine DTCs.
Erase DTC P0700 under engine to turn off the MIL off after completion of transmission repairs.
Perform *PRNDL FAULT CLEARING PROCEDURE after completion of repairs for P0706-TRANSMISSION
RANGE SENSOR RATIONALITY.
If the Powertrain Control Module or the Transmission has been repaired or replaced, it is necessary to perform
the scan tool Quick Learn Procedure.
If the Torque converter has been replaced, with the scan tool perform TCC BREAK-IN.
If the Powertrain Control Module or Front Control Module has been replacedyoumustresetthePinionFactor
in the Front Control Module.
With the scan tool, display Transmission Temperature. Start and run the engine until the Transmission Tem-
perature is HOT, above 43° C or 110° F.
Check the transmission fluid and adjust if necessary. Refer to the ServiceInformation for the Fluid Fill proce-
dure.
Road test the vehicle. With the scan tool, monitor the engine RPM. Make 15 to20 1-2, 2-3, 3-4 upshifts.
Perform these shifts from a standing start to 45 mph with a constant throttleopeningof20to25degrees.
With speeds below 25 MPH, make 5 to 8 wide open throttle kickdowns to 1st gear. Allow at least 5 seconds
each in 2nd and 3rd gear between each kickdown.
For a specific DTC, drive the vehicle to the Symptom’s When Monitored/WhenSet conditions to verify the DTC
is repaired.
If equipped with AutoStick, upshift and downshift several times using the AutoStickfeature during the road
test.
Note: Use the OBDII task manager to run a Good Trip in each gear, this will confirm the repair and to
ensure that the DTC has not re-matured.
Check for any Diagnostic Trouble Codes (DTCs) during and after the road test.
Did any Diagnostic Trouble Codes set during the road test?
Ye s>>
Repair is not complete. Refer to the Transmission category and perform theappropriate symptom(s).
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - DIAGNOSIS AND TESTING)
No>>
Repair is complete.
REVERSE GEAR POWERFLOW
In reverse, input power is through the reverse clutch (1). When applied, the reverse clutch drives the front sun gear
through the overdrive hub and shaft. The L/R clutch (2) is applied to hold the front carrier/rear annulus assembly
stationary. The front carrier is being held by the L/R clutch so the pinionsare forced to rotate the front annulus/rear
carrier assembly in the reverse direction. Output torque is provided, in reverse, with a gear ratio of 2.21:1.
DIAGNOSIS AND TESTING
AUTOMATIC TRANSMISSION
CAUTION: Before attempting any repair on the 42RLE Four Speed Automatic Transmission, always check
for proper shift cable adjustment. Also check for diagnostic trouble codes with the scan tool and the 42RLE
Transmission Diagnostic information.
42RLE automatic transmission malfunctions may be caused by these generalconditions:
Poor engine performance
Improper adjustments
Hydraulic malfunctions
Mechanical malfunctions
Electronic malfunctions
When diagnosing a problem always begin with recording the complaint. The complaint should be defined as specific
as possible. Includethe following checks:
Temperature at occurrence (cold, hot, both)
Reverse Gear Powerflow
1 - LOW-REVERSE CLUTCH APPLIED (Holds Rear Annulus Front Carrier)
2 - REVERSE CLUTCH APPLIED (Turns Front Sun)
HYDRAULIC PRESSURE TESTS
Pressure testing is a very important step in the diag-
nostic procedure. These tests usually reveal the cause
of most transmission problems.
Before performing pressure tests, be certain that fluid
level and condition, and shift cable adjustments have
been checked and approved. Fluid must be at operat-
ing temperature (150 to 200 degrees F.).
Install an engine tachometer, raise vehicle on hoist
which allows the wheels to turn, and position tachom-
eter so it can be read.
Using special adapters L-4559, attach 300 psi
gauge(s) C-3293SP to the port(s) required for test
being conducted.
Test port locations are shown in the Pressure Taps
graphic.
TEST ONE - SELECTOR IN MANUAL 1 (1st Gear)
NOTE: This test checks pump output, pressure regulation and condition of the low/reverse clutch hydraulic
circuit and shift schedule.
1. Attach pressure gauge to the low/reverse clutch tap.
2. Move selector lever to the MANUAL 1 position.
3. Allow vehicle wheels to turn and increase throttle opening to achieve anindicatedvehiclespeedto20mph.
4. Low/reverse clutch pressure should read 115 to 145 psi.
TEST TWO - SELECTOR IN MANUAL 2 (Second Gear)
NOTE: This test checks the underdrive clutch hydraulic circuit as well as the shift schedule.
1. Attach gauge to the underdrive clutch tap.
2. Move selector lever to the MANUAL 2 position.
3. Allow vehicle wheels to turn and increase throttle opening to achieve anindicated vehicle speed of 30 mph.
4. In second gear the underdrive clutch pressure should read 110 to 145 psi.
TEST TWO A - SELECTOR IN DRIVE (OD ON - Fourth Gear)
NOTE: This test checks the underdrive clutch hydraulic circuit as well as the shift schedule.
1. Attach gauge to the underdrive clutch tap.
2. Move selector lever to the DRIVE position. Verfy that the OD switch is ON.
3. Allow wheels to rotate freely and increase throttle opening to achieve an indicated speed of 40 mph.
4. Underdrive clutch pressure should read below 5 psi. If not, than either the solenoid assembly or controller is at
fault.
Pressure Taps
1 - TORQUE CONVERTER CLUTCH OFF
2 - REVERSE
3 - LOW/REVERSE
4-2/4
5 - UNDERDRIVE
6 - TORQUE CONVERTER CLUTCH ON
7-OVERDRIVE