DODGE RAM SRT-10 2006 Service Repair Manual

P0720-OUTPUT SPEED SENSOR CIRCUIT
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 there is an excessive change in output RPM in any gear. This DTC can take upto five minutes of problem
identification beforeilluminating the MIL.
Possible Causes
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT OPEN
(T13) SPEED SENSOR GROUND CIRCUIT OPEN
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO GROUND
(T13) SPEED SENSOR GROUND CIRCUIT SHORT TO GROUND
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
(T13) SPEED SENSOR GROUND CIRCUIT SHORT TO VOLTAGE
OUTPUT SPEED SENSOR
POWERTRAIN CONTROL MODULE
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - 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
the following checks:
1) When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding in-gear trouble code
is set (codes P0731 through P0736).
2) An excessive change in input or output speeds indicating signal intermittent will result in codes P0715 and/or
P0720 being set.
3) If the common speed sensor ground circuit is lost, both sensor inputs will read the signal from the input speed
sensor at idle in neutral. Since the input speed sensor has 60 teeth and the output speed sensor has 30 teeth, this
results in a an apparent speed ratio of 1:2 and may cause the DTC P1794 to set.
Diagnostic Test
1.CHECK TO SEE IF DTC P0720 IS CURRENT
Turn the ignition off to the lock position.
CAUTION: Properly support the vehicle and raise all drive wheels off the ground.
Release the parking brake.
Start the engine in park.
Place the transmission gear selector in drive, release foot from brake.
WARNING: Be sure to keep hands and feet clear of rotation wheels.
With the scan tool, monitor the Output Speed Sensor RPM.
Is the Output Speed Sensor RPM below 100 RPM?
Ye s>>
Go To 2
No>>
Go To 9

2.OUTPUT SPEED SENSOR
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.
Ignition on, engine not running.
With the Transmission Simulator, set the selector switch to 3000/1000 andthe Input/Output switch to ON.
With the scan tool, monitor the Input and Output Speed Sensor RPM
Does the Input Speed read 3000 RPM and the Output Speed read 1000 RPM, ± 50 RPM?
Ye s>>
Replace the Output Speed Sensor per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 3
3.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the Transmission Simulator, Miller tool #8333.
Disconnect the PCM harness connectors and connect Miller special tool
#8815.
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 resistance of the (T14) Output Speed Sensor Signal circuit
from the Output Speed Sensor harness connector to the appropriate
terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T14) Output Speed Sensor Signal circuit for an
open.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 4

4.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR AN OPEN
Measure the resistance of the (T13) Speed Sensor Ground circuit from
the Output Speed Sensor harness connector to the appropriate terminal
in the Miller tool #8815.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for an open.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 5
5.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T14) Output Speed
Sensor Signal circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T14) Output Speed Sensor Signal circuit for a
short to ground.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 6

6.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T13) Speed Sensor
Ground circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for a short to
ground.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 7
7.CHECK THE (T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
Ignition on, engine not running.
With the scan tool in TIPM, actuate the TCM output.
Measure the voltage of the (T14) Output Speed Sensor Signal circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T14) Output Speed Sensor Signal circuit for a
short to voltage.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 8

8.CHECK THE (T13) SPEED SENSOR GROUND CIRCUIT FOR A SHORT TO VOLTAGE
With the scan tool in TIPM, actuate the TCM output.
Measure the voltage of the (T13) Speed Sensor Ground circuit.
Is the voltage above 0.5 volts?
Ye s>>
Repair the (T13) Speed Sensor Ground circuit for a short to
voltage.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
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 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
9.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 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.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .

P0725-ENGINE SPEED SENSOR CIRCUIT
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Continuously every 7 msec with the ignition on and engine running.
Set Condition:
This DTC will set when the calculated engine speed is less than 390 RPM with the engine running, or greater
than 8000 RPM, for the period of 2.0 seconds. The PCM will place the Transmission in Limp-in when this DTC
is set.Note: This is not a Transmission Input Speed Sensor DTC.
Possible Causes
RELATED ENGINE DTC’S PRESENT
CRANK POSITION SENSOR OR WIRING
POWERTRAIN CONTROL MODULE
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Theory of Operation
The Transmission Control System calculates the engine RPM by directly reading the engine crank position sensor.
It compares the calculated value to the engine speed sensor signal transmitted from the Engine Control System
over the controllers internal BUS. The calculated engine RPM is also comparedtoaminimumandamaximum
value.Note: Due to the integration of the Powertrain Control Module (PCM) and Transmission Control Mod-
ule (TCM), BUS communication between the modules is internal and unserviceable.
Diagnostic Test
1.CHECKFORRELATEDENGINEDTCS
NOTE: This is not a Transmission Input Speed Sensor DTC.
Ignition on, engine not running.
With the scan tool, read all Engine DTCs. This includes any active or storedor one trip DTCs.
Are there any engine RPM related DTCs present?
Ye s>>
Refer to the Powertrain category and perform the appropriate symptom.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 2
2.CHECK IF DTC IS CURRENT
Ignition on, engine not running.
With a scan tool, read and record all DTC EVENT DATA.
Withthescantool,eraseallactiveandstoredtransmissionDTCs.(Note:it may be necessary to perform a battery
disconnect with the scan tool to clear DTC EVENT DATA.)
Using the DTC EVENT DATA, duplicate theconditions in which the original DTCset.
With the scan tool, read transmission and engine DTCs.
NOTE: Refer to all engine DTCs first in the following question.
Pick the answer below that best describes your findings, (this includes one trip failures).
Transmission DTC P0725 set
Using the schematics as a guide, check the Powertrain Control Module (PCM)terminals for corrosion,
damage, or terminal push out. Also check the Crank Position sensor and wiring. 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 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Engine DTC set
Refer to the Driveability category and perform the appropriate symptom.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No DTC set at all
Go To 3
3.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.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .

P0731-GEAR RATIO ERROR IN 1ST
For a complete wiring diagramRefer to Section 8W
When Monitored:
Continuously with the ignition on, engine running, with the transmissionin gear.
Set Condition:
If the ratio of the Input RPM to the Output RPM does not match the current gearratio. This DTC can take up
to five minutes of problem identification before illuminating the MIL
Possible Causes
CUT UD PISTON SEAL
LOW FLUID LEVEL
CRACKED OR MIS-INSTALLED PRIMARY OIL FILTER OR SEAL
STUCK OR STICKING MAIN REGULATOR VALVE
FAILED OVERRUNNING CLUTCH
CUT UD ACCUMULATOR SEAL RING
BROKEN UD ACCUMULATOR PISTON
BROKEN REACTION SHAFT SUPPORT SEAL RING
LOW LINE PRESSURE
BROKEN / MISSING MAIN VALVE BODY BLEED ORIFICE
BROKEN / MISSING DRIBBLER ORIFICE ASSEMBLY IN REACTION SHAFT SUPPORT
POOR MACHINING ON PUMP VALVE BODY FACE
INPUT SPEED SENSOR AND RELATED WIRING
TRANSMISSION SOLENOID/TRS ASSEMBLY
POWERTRAIN CONTROL MODULE
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - 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
the following checks:
1) Once in a particular gear, if the gear ratio varies from the correct gear ratio, the corresponding in-gear trouble
code is set (DTCs P0731–36).
2) An excessive change in input or output speeds indicating signal intermittent may result in the DTCs P0715 and/or
P0720 being set.
3) If the common speed sensor ground circuit is lost, both sensor inputs will read the pulses from the input speed
sensor when at a stop in neutral. Since the input speed sensor reads 60 teethfrom the input clutch hub and the
output speed sensor reads 30 teeth from the park gear, the result is an apparent speed ratio of 1:2 and may cause
the DTC P1794 to set.

Diagnostic Test
1.CHECKFORRELATEDDTCS
With the scan tool, check for other transmission DTCs.
If any of these DTCs are present, perform their respective tests first.
Are there any Transmission; solenoid, line pressure, speed sensor, and/or loss of prime DTC’s present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom. If any of these DTCs are
present, they may cause a Speed Ratio Error. Perform the test for P0944 firstifitispresent.
No>>
Go To 2
2.CHECK IF DTC 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>>
Go To 4
3.CHECK FOR INTERMITTENT OPERATION
The conditions to set this DTC are not currently present.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
If the DTC Event Data shows fault P0731 was set in Park, Reverse, or Neutral,replace the Powertrain Control
Module.
If the DTC Event Data shows fault P0731 set with input RPM = zero, check the input speed sensor and related
wiring.
If the DTC Event Data shows fault P0731 set with line pressure significantly below desired line pressure, check
for the cause of low line pressure (i.e., oil level, mis-installed or damaged primary filter or filter seal, sticking
main regulator valve in pump, etc.).
If the DTC Event Data shows fault P0731 set with the UD pressure switch open (but line pressure matches
Desired Line Pressure), air check the UD hydraulic clutch circuit for leakage per the Service Information. If the
UD hydraulic clutch circuit is OK, replace the solenoid/TRS assembly.
Check the gearshift linkage adjustment.
Intermittent Gear Ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed
Sensor Ground circuit.
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.
Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator.
Gear ratio DTCs can also be set under extreme temperature conditions.
Verify if the problem is only experienced under extreme hot or cold conditions.
Were there any problems found.
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .