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P1766

DTC P1766 (P0715): Input Shaft Speed Sensor System











CIRCUIT OPERATION
^ The input shaft speed sensor generates 0 - 5 volts pulse signal when the input shaft rotates. The pulse signal frequency increases with a rise in input shaft speed.
^ The input shaft speed sensor is connected to the PCM, (terminals 111 and 113) via the input shaft speed sensor connector (terminals 1 and 2).
^ The PCM, detects the input shaft speed by the signal input to terminal 111.
^ The input shaft speed sensor generates the pulse signal as the teeth of the underdrive clutch retainer pass the magnetic tip of the sensor.

DESCRIPTIONS OF MONITOR METHODS
^ If there is no detection pulse from input shaft speed sensor (turbine rotation) even during driving test at more than specified speed, PCM, judges that input 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 P1767 (P0720): Output shaft speed sensor malfunction

Sensor (The sensor below is determined to be normal)
^ Output shaft speed sensor

LOGIC FLOW CHARTS (Monitor Sequence):





DTC SET CONDITIONS

Check Conditions
^ Transmission range switch position: D, 3, 2 or L.
^ Output speed: 1,000 r/min or more. [4A/T]
^ Vehicle speed: 30 km/h (19 mph). [5A/T]
^ Transmission fluid temperature sensor voltage: 4.5 volts or less.

Judgement Criteria
^ Input shaft speed sensor signal: no signal change. (4 seconds)
^ If DTC P1766 (P0715) 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, shift to 3rd gear or higher, and drive at 40 km/h (25 mph) or more for 10 seconds.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the input shaft speed sensor
^ Malfunction of the underdrive clutch retainer
^ Damaged harness or connector
^ Malfunction of the PCM

DIAGNOSIS

Required Special Tool:
^ MB991958: Scan Tool (M.U.T-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: M.U.T-III USB Cable
^ MB991910: M.U.T-III Main Harness A

STEP 1. Using scan tool MB991958, check data list item 5: Input Shaft Speed Sensor.

CAUTION





To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1) Connect scan tool MB991958 to the data link connector.
2) Start the engine.
3) Set scan tool MB991958 to data reading mode.
^ Item 5: Input Shaft Speed Sensor.
^ When driving at constant speed of 50 km/h (31 mph), the display should be "1,400 - 1,700 r/min" (Gear range: 3rd gear). [4A/T]
^ When driving at constant speed of 60 km/h (37 mph), the display should be "1,400 - 1,700 r/min" (Gear range: 4th gear). [5A/T]
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: Go to Step 2.

STEP 2. Measure the power supply voltage at the input shaft speed sensor connector B-109.





1) Disconnect connector B-109 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 A-13, joint connector (1) C-01 and junction block connector C-214 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 input shaft speed sensor connector B-109 terminal 3 and the junction block connector C-214 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 input shaft speed sensor connector B-109.





1) Disconnect connector B-109 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 B-22 by using check harness special tool MB991923.





1) Disconnect all the connectors from the PCM,





2) Connect special tool MB991923 (check harness) between the PCM, and the body-side harness connector.
3) Turn the ignition switch to the "ON" position.





4) Measure the voltage between PCM terminal 111 and ground.
^ 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 PCM, connector B-22 and input shaft speed sensor connector B-109 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 PCM, connector B-22 terminal 111 and input shaft speed sensor connector B-109 terminal 2.





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





STEP 9. Check PCM connector B-22 and input shaft speed sensor connector B-109 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 PCM, connector B-22 terminal 111 and input shaft speed sensor connector B-109 terminal 2.





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 input shaft speed sensor connector B-109.





1) Disconnect connector B-109 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 B-22 by using check harness special tool.





1) Disconnect all the connectors from the PCM,





2) Connect special tool MB991923 (check harness) between the PCM, and the body-side harness connector.
3) Turn the ignition switch to the "ON" position.





4) Measure the resistance between terminal 113 and ground.
^ The resistance should measure less than 2 ohms.
5) 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 PCM, connector B-22 and input shaft speed sensor connector B-109 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 PCM, connector B-22 terminal 113 and input shaft speed sensor connector B-109 terminal 1.





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 B-22 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 input shaft speed sensor waveform at PCM connectors B-22 by using check harness special tool MB991923.





1) Disconnect all the connectors from the PCM.





2) Connect special tool MB991923 (check harness) between the PCM and the body-side harness connector.





3) Connect an oscilloscope probe to PCM, connector B-22 terminal 111 and to 113.
4) Start the engine and drive the vehicle at constant speed of 50 km/h (31 mph) (Gear range: 3rd gear) [4A/T] or 60 km/h (37 mph) (Gear range: 4th gear) [5A/T].





5) Check the input shaft speed sensor waveform. The input shaft speed sensor waveform should show a pattern similar to the illustration. The maximum value should be 4.8 volts or more and the minimum value 0.8 volt or less. The output waveform should not contain electrical noise.
6) 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 input shaft speed sensor.





1) Replace the input shaft speed sensor.
2) Test drive the vehicle.
3) Check for A/T diagnostic trouble code.
Q: Is A/T DTC P1766 set?
YES: Go to Step 18.
NO: The procedure is complete.

STEP 18. Replace the underdrive clutch retainer.





1) Replace the underdrive clutch retainer.
2) Test drive the vehicle.
3) Check for A/T diagnostic trouble code.
Q: Is A/T DTC P1766 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 MB991958, check data list item 5: Input Shaft Speed Sensor.

CAUTION





To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1) Connect scan tool MB991958 to the data link connector.
2) Start the engine.
3) Set scan tool MB991958 to data reading mode.
^ Item 5: Input Shaft Speed Sensor.
^ When driving at constant speed of 50 km/h (31 mph), the display should be "1,400 - 1,700 r/min" (Gear range: 3rd gear). [4A/T]
^ When driving at constant speed of 60 km/h (37 mph), the display should be "1,400 - 1,700 r/min" (Gear range: 4th gear). [5A/T]
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. When the PCM is replaced, register the encrypted code.

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