P0725-ENGINE SPEED SENSOR CIRCUIT
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Whenever the engine is running.
Set Condition:
The Engine RPM is less than 390 or greater than 8000 for more than 2 seconds while the engine is running.
Possible Causes
ENGINE DTCS PRESENT
POWERTRAIN CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
Theory of Operation
The PCM uses a dual port RAM internal to the controller to send the engine speed signal to the Transmission
Control System. The calculated engine RPM is compared to a minimum and maximum value. If the PCM interprets
this signal to be out of range when the engine is running the code is set. The MIL illuminates after 10 seconds of
vehicle operation and the transmission system defaults to Limp-in mode.
Diagnostic Test
1.CHECK IF THE DTC IS CURRENT
Start the engine.
NOTE: This DTC is not a Transmission Input Speed Sensor DTC.
With the scan tool, read transmission DTCs.
Is the status Active for this DTC or is the STARTS SINCE SET counter set at 0?
Ye s>>
Go To 2
No>>
Go To 3
2.CHECK IF ENGINE DTCS ARE PRESENT
With the scan tool, read engine DTCs.
Are there any engine DTC’s present?
Ye s>>
Refer to Section 9 – Engine Electrical Diagnostics and perform the appropriate diagnostic procedure.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 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 Ser-
vice 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/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
P0731-GEAR RATIO ERROR IN 1ST
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 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/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 DTC’s 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 1st 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 as necessary. Check all of the components relatedtotheUDandLR
clutches. Inspect the Oil Pump and repair or replace as necessary. Refer tothe Service Information for
the proper repair procedures.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
3.CHECK FOR INTERMITTENT OPERATION
The conditions to set this DTC are not current at this time.
Check the gearshift linkage adjustment.
Gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits. If the vehicle passes the
Clutch Test and still sets 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 .
P0732-GEAR RATIO ERROR IN 2ND
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
TRANSMISSION SOLENOID/PRESSURE SWITCH ASSEMBLY
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.CHECK 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 IF THE DTC IS CURRENT
With the scan tool, perform the 2nd 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>>
Go To 4
3.CHECK FOR INTERMITTENT OPERATION
The conditions to set this DTC are not current at this time.
Check the gearshift linkage adjustment.
Gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits. If the vehicle passes the
Clutch Test and still sets 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 to 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.
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 DTCs P0845 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>>
Repair internal Transmission per the Service Information. Check all of the components related to the UD
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)
P0733-GEAR RATIO ERROR IN 3RD
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
TRANSMISSION SOLENOID/PRESSURE SWITCH ASSEMBLY
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.CHECK 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.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 2
2.CHECK IF THE DTC IS CURRENT
With the scan tool, perform the 3rd 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>>
Go To 4
3.CHECK FOR INTERMITTENT OPERATION
The conditions to set this DTC are not current at this time.
Check the gearshift linkage adjustment.
Gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits. If the vehicle passes the
Clutch Test and still sets 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.
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 DTCs.
Are the DTCs 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.
No>>
Repair internal Transmission per the Service Information. Check all of the components related to the UD
and O/D 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)
P0734-GEAR RATIO ERROR IN 4TH
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
TRANSMISSION SOLENOID/PRESSURE SWITCH ASSEMBLY
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.CHECK 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 IF THE DTC IS CURRENT
With the scan tool, perform the 4th 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>>
Go To 4