Code No.P0722: Output Shaft Speed Sensor System (No Signal), P077C: Output Shaft Speed Sensor System (Low Circuit), P077D: Output Shaft Speed Sensor System (High Circuit)

PROBABLE CAUSES

OPERATION

The output shaft speed sensor detects the speed of rear ring gear, and sends the pulse signal to A/T-ECU.

DIAGNOSIS CODE SET CONDITIONS

While the engine is running, if any output shaft speed sensor pulse signal is not detected even when the input shaft speed sensor pulse signal is detected, code No.P0722 is set.
While the engine is running, when a status continues for 1 second with which the monitor voltage from output shaft speed sensor 1 is less than standard value, code No.P077C is set.
While the engine is running, when a status continues for 0.5 second with which the monitor voltage from input shaft speed sensor 1 is higher than standard value, code No.P077D is set.

PROBABLE CAUSES

Malfunction of output shaft speed sensor
Malfunction of rear ring gear
Damaged harness wires and connectors
Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Measure the resistance at AT-ECU connector.

Disconnect the connector, and measure the resistance between terminal PGB+ and PGB- line at the wiring harness side.

OK: 2 Ω or less

Q. Is the check result normal?

	Go to Step 3.

	Go to Step 2.

STEP 2. Measure the resistance at transmission wiring harness connector.

Disconnect the connector, and measure the resistance between terminal PGB+ and PGB- line at the transmission assembly side.

OK: 2 Ω or less

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 6.

STEP 3. Measure the resistance at A/T-ECU connector.

Disconnect the connector, and measure the resistance between terminal PGB+ and body earth at the wiring harness side.
Disconnect the connector, and measure the resistance between terminal PGB- and body earth at the wiring harness side.

OK: No continuity

Q. Is the check result normal?

	Go to Step 8.

	Go to Step 4.

STEP 4. Measure the resistance at transmission wiring harness connector.

Disconnect the connector, and measure the resistance between terminal PGB+ and body earth at the transmission assembly side.
Disconnect the connector, and measure the resistance between terminal PGB- and body earth at the transmission assembly side.

OK: No continuity

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 6.

STEP 5. Check for open circuit and short circuit in PGB+, PGB- line between transmission wiring harness connector and A/T-ECU connector.

Q. Is the check result normal?

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

	Repair the connector(s) or wiring harness.

STEP 6. Check for open circuit and short circuit in PGB+, PGB- line between transmission wiring harness connector and output shaft speed sensor connector.

Refer to

Q. Is the check result normal?

	Go to Step 7.

	Repair the connector(s) or wiring harness, or replace the transmission wiring harness.

STEP 7. Check the output shaft speed sensor.

Refer to

Q. Is the check result normal?

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

	Replace the output shaft speed sensor.

STEP 8. Check whether the diagnosis code is set again.

Ignition switch: "LOCK"(OFF) → "ON"
Check again if the diagnosis code is set.

Q. Is diagnosis code No.P0722, P077C, P077D set?

	Replace the A/T-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).