P0720

DTC 23 (P0720): Output Shaft Speed Sensor System














CIRCUIT OPERATION
^ The output shaft speed sensor generates a 0 <-> 5 volt pulse signal when the output shaft rotates. The pulse signal frequency increases with a rise output shaft speed.
^ The output shaft speed sensor is connected to the PCM (terminals 16 and 104) via the output shaft speed sensor connector (terminals 1 and 2).
^ The PCM detects the output shaft speed by the signal input to terminal 104.
^ The output shaft speed sensor generates the pulse signal as the teeth of the transfer drive gear pass the magnetic tip of the sensor.

DESCRIPTIONS OF MONITOR METHODS
^ If abruptly reduced output revolution is detected during driving test, and a difference between turbine revolution and that value calculated from output revolution equals or exceeds specified value, PCM judges that output shaft speed sensor has a failure.
^ If there is no detection pulse from output shaft speed sensor (output rotation) even when engine revolution and turbine revolution both equal or exceed specified value, PCM judges that output shaft speed sensor has a failure.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
^ DTC 22 (P0715): Input shaft speed sensor malfunction
^ DTC 36 (P0743): Torque converter clutch solenoid malfunction
^ DTC 31 (P0753): Low and reverse solenoid malfunction
^ DTC 32 (P0758): Underdrive solenoid malfunction
^ DTC 33 (P0763): Second solenoid malfunction
^ DTC 34 (P0768): Overdrive solenoid malfunction
^ DTC 54 (P1751): A/T control relay malfunction
Sensor (The sensor below is determined to be normal)
^ Input shaft speed sensor
^ Torque converter clutch solenoid
^ Low and reverse solenoid
^ Underdrive solenoid
^ Second solenoid
^ Overdrive solenoid
^ A/T control relay

LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS
Check Conditions
^ Transmission range switch position: D, 3, 2 or L.
^ Input speed: 1,000 r/min or more.
^ Engine speed: 1,000 r/min or more.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Calculated slip (engine speed - input speed): 100 r/min or more.

Judgement Criteria
^ Output speed: no signal change. (4 seconds)
^ If DTC 23 (P0720) is set consecutively four times, the transaxle is locked into 3rd gear or 2nd gear as a fail-safe measure, and the "N" range light flashes once per second.

Check Conditions
^ Transmission range switch position: D, 3, 2 or L.
^ Input speed: 500 r/min or more.
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.
^ Rapid output speed change: -31.9 r/min /0.016 second or less.

Judgement Criteria
^ Output speed: [(input speed - 200 r/min) / gear ratio] or less. (4 seconds)
^ If DTC 23 (P0720) is set consecutively four times, the transaxle is locked into 3rd gear or 2nd gear as a fail-safe measure, and the "N" range light flashes once per second.

OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive for 5 seconds, with 1st gear fixed (L range or 1st gear in sport mode), at 20 km/h (12 mph) or more with 50% or more of accelerator pedal depressing. Then stop the vehicle, and drive again for 5 seconds, with 1st gear fixed (L range or 1st gear in sport mode), at 20 km/h (12 mph) or more with 50% or more of accelerator pedal depressing.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the output shaft speed sensor
^ Malfunction of the transfer drive gear or driven gear
^ Damaged harness or connector
^ Malfunction of the PCM

DIAGNOSIS
Required Special Tool:
^ MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 23: Output Shaft Speed Sensor.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1 Connect scan tool MB991502 to the data link connector.
2 Start the engine.
3 Set scan tool MB991502 to the data reading mode for item 23, Output Shaft Speed Sensor.
^ When driving at a constant speed of 50 km/h (31 mph), the display should be "1,600 - 1,900 r/min." <2.4L Engine>, "1,100- 1,600 r/min." <3.0L Engine> (Gear range: 3rd gear)
4 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor within the specified range?
YES: It can be assumed that this malfunction is intermittent.
NO: Go to Step 2.

STEP 2. Measure the power supply voltage at the output shaft speed sensor connector B-108.

1 Disconnect connector B-108 and measure at the harness side.
2 Turn the ignition switch to the "ON" position.

3 Measure the voltage between terminal 3 and ground.
^ The voltage should measure battery positive voltage.
4 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?
YES: Go to Step 5.
NO: Go to Step 3.

STEP 3. Check intermediate connector C-25 and junction block connector C-312 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged components.

STEP 4. Check the harness for open circuit or short circuit to ground between the output shaft speed sensor connector B-108 terminal 3 and the junction block connector C-312 terminal 12.

Q: Is the harness wire in good condition?
YES: Go to Step 5.
NO: Repair or replace the harness wire.

STEP 5. Measure the PCM to speed sensor output voltage at the output shaft speed sensor connector B-108.

1 Disconnect connector B-108 from the speed sensor and measure voltage at the harness side.
2 Turn the ignition switch to the "ON" position.

3 Measure the voltage between terminal 2 and ground.
^ The voltage should measure between 4.5 and 4.9 volts.
4 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?
YES: Go to Step 11.
NO: Go to Step 6.

STEP 6. Measure the PCM output voltage to the speed sensor at the PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing.

1 Do not disconnect connector C-121 <2.4L Engine> or C-123 <3.0L Engine>.
2 Disconnect connector B-108 at the output shaft speed sensor.
3 Turn the ignition switch to the "ON" position.

4 Measure the voltage between PCM terminal 104 and ground by backprobing.
^ The voltage should measure between 4.5 and 4.9 volts.
5 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?
YES: Go to Step 7.
NO: Go to Step 9.

STEP 7. Check output shaft speed sensor connector B-108 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors in good condition?
YES: Go to Step 8.
NO: Repair or replace the damaged components.

STEP 8. Check the harness for open circuit or damage between output shaft speed sensor connector B-108 terminal 2 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> terminal 104.

Q: Is the harness wire in good condition?
YES: Go to Step 19.
NO: Repair or replace the harness wire.

STEP 9. Check output shaft speed sensor connector B-108 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition?
YES: Go to Step 10.
NO: Repair or replace the damages components.

STEP 10. Check the harness for short circuit to ground between output shaft speed sensor connector B-108 terminal 2 and PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> terminal 104.

Q: Is the harness wire in good condition?
YES: Go to Step 11.
NO: Repair or replace the harness wire.

STEP 11. Measure the ground circuit for resistance at the output shaft speed sensor connector B-108.

1 Disconnect connector B-108 from the speed sensor and measure at the harness side.

2 Measure the resistance between terminal 1 and ground.
^ The resistance should measure less than 2 ohms.
Q: Is the measured resistance less than 2 ohms?
YES: Go to Step 16.
NO: Go to Step 12.

STEP 12. Measure the resistance at the PCM connector C-110 <2.4L Engine> or C-112 <3.0L Engine> by backprobing.

1 Do not disconnect connector C-110 <2.4L Engine> or C-112 <3.0L Engine>.
2 Turn the ignition switch to the "ON" position.

3 Measure the resistance between terminal 16 and ground by backprobing.
^ The resistance should measure less than 2 ohms.
4 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured resistance less than 2 ohms?
YES: Go to Step 13.
NO: Go to Step 15.

STEP 13. Check output shaft speed sensor connector B-108 and PCM connector C-110 <2.4L Engine> or C-112 <3.0L Engine> for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition?
YES: Go to Step 14.
NO: Repair or replace the damaged components.

STEP 14. Check the harness for open circuit or damage between output shaft speed sensor harness side connector B-108 terminal 1 and PCM connector C-110 <2.4L Engine> or C-112 <3.0L Engine> terminal 16.

Q: Is the harness wire in good condition?
YES: Go to Step 16.
NO: Repair or replace the harness wire.

STEP 15. Check PCM connector C-110 <2.4L Engine> or C-112 <3.0L Engine> for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are the connector and terminals in good condition?
YES: Replace the PCM.
NO: Repair or replace the damaged components.

STEP 16. Using the oscilloscope, check the output shaft speed sensor waveform at PCM connectors C-110 <2.4L Engine> or C-112 <3.0L Engine> and C-121 <2.4L Engine> or C-123 <3.0L Engine> by backprobing.

1 Do not disconnect connectors C-110 <2.4L Engine> or C-112 <3.0L Engine> and C-121 <2.4L Engine> or C-123 <3.0L Engine>.

2 Connect an oscilloscope probe to PCM connector C-110 <2.4L Engine> or C-112 <3.0L Engine> terminal 16 and to PCM connector C-121 <2.4L Engine> or C-123 <3.0L Engine> terminal 104 by backprobing.
3 Start the engine and drive the vehicle at constant speed of 50 km/h (31 mph). (Gear range: 3rd gear)

4 Check the output shaft speed sensor waveform.
^ The output shaft speed sensor waveform should show a pattern similar to the illustration. The maximum value should be 4.8 volts and more and the minimum value 0.8 volt and less. The output waveform should not contain electrical noise.
5 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?
YES: Go to Step 19.
NO: Go to Step 17.

STEP 17. Replace the output shaft speed sensor.

1 Replace the output shaft speed sensor.
2 Test drive the vehicle.
3 Check for A/T DTC.
Q: Is A/T DTC 23 set?
YES: Go to Step 18.
NO: The procedure is complete.

STEP 18. Replace the transfer drive gear or driven gear.

1 Replace the transfer drive gear or driven gear.
2 Test drive the vehicle.
3 Check for A/T DTC.
Q: Is A/T DTC 23 set?
YES: An A/T DTC may have set due to external radio frequency interference (RFI) possibility caused by cellular phone activity, or aftermarket components installed on the vehicle.
NO: The procedure is complete.

STEP 19. Using scan tool MB991502, check data list item 23: Output Shaft Speed Sensor.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1 Connect scan tool MB991502 to the data link connector.
2 Start the engine.
3 Set scan tool MB991502 to data reading mode for item 23, Output Shaft Speed Sensor.
^ When driving at constant speed of 50 km/h (31 mph), the display should be "1,600 - 1,900 r/min." <2.4L Engine>, "1,300- 1,600 r/min." <3.0L Engine> (Gear range: 3rd gear)
4 Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Replace the PCM.