P0725

DTC P0725: Malfunction of Engine Speed

DIAGNOSTIC FUNCTION
TCM detects malfunction of engine speed received from the ECM by comparing the primary pulley speed with the secondary pulley speed.

DESCRIPTIONS OF MONITOR METHODS
^ Locked up with the primary pulley speed of 1,000 r/min or more and with the engine speed of 450 r/min or less
^ TCM detects the malfunction in the engine speed by comparing it with the primary pulley speed.
^ CAN communication error occurs between ECM and TCM.

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)
^ P0705: Malfunction of transmission range switch
^ P0715: Malfunction of primary pulley speed sensor
^ P0741: Abnormality in lockup function
^ P0746: Abnormality in hydraulic control system function
^ P0841: Abnormality in line pressure sensor function
^ P1706: Malfunction of throttle signal

Sensor (The sensor below is determined to be normal)
^ Transmission range switch
^ Primary pulley speed sensor
^ Accelerator pedal position sensor

LOGIC FLOW CHARTS (Monitor Sequence)

Logic Flow Charts (Monitor Sequence):

DTC SET CONDITIONS

Check Conditions
^ Transmission range switch position: D.
^ Vehicle speed: 10 km/h (6.2 mph) or more.
^ Throttle position: 1/8 or more.
^ Engine speed: 450 r/min or more.
^ Voltage of battery: 9 volts or more.
^ Voltage of battery: 16 volts or less.
^ Transmission range switch: normal.
^ Primary pulley speed sensor: normal.
^ Secondary pulley speed sensor: normal.
^ Engine revolution: normal.
^ Throttle position sensor: normal.

Judgement Criteria
^ Engine revolution [primary pulley revolution: 1,000 r/min or more]: less than 450 r/min.
^ The difference of engine revolution and primary revolution: more than 1,000 r/min. (5 seconds)
^ The difference of engine revolution and secondary revolution: more than 1,000 r/min. (5 seconds)
^ The difference of primary revolution and secondary revolution: 1,000 r/min or less.

OBD-II DRIVE CYCLE PATTERN
All the conditions below continue for 6 seconds.
^ Transmission range switch: D
^ Vehicle speed: 10 km/h (6.2 mph) or more
^ Throttle position: 1/8 or more
^ Engine speed: 450 r/min or more
^ Transmission fluid temperature: 20°C (68°F) or more.
^ Transmission fluid temperature: 99°C (210°F) or more.

PROBABLE CAUSES
^ Malfunction of the CAN bus
^ Malfunction of the engine system
^ Malfunction of TCM

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to perform the CAN bus diagnosis.

Q: Is the check result normal?
YES: Go to Step 2.
NO: Go to "CAN Troubleshooting."

STEP 2. M.U.T.-III diagnosis code
Check if the engine-related diagnosis code is set.

Q: Is the check result normal?
YES: Go to Step 3.
NO: Go to "Engine Troubleshooting."

STEP 3. Symptom recheck after erasing diagnosis code

Q: Is the check result normal?
YES: Intermittent malfunction
NO: Replace TCM.