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DTC P0977: Malfunction of the High Clutch and Reverse Brake Solenoid Valve (open circuit / short to power supply)
 
 
 
 
DIAGNOSTIC FUNCTION
The TCM monitors the high clutch and reverse brake solenoid valve circuit for open or short to power supply.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • Owing to open circuit or short to power supply, less current than predetermined flows into the high clutch and reverse brake solenoid valve drive circuit.
 
 
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)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Voltage of battery: 10 volts or more.
  • Voltage of battery: 16.5 volts or less.
Judgment Criteria
  • All the conditions listed below remain for 0.2 seconds.
    1. The high clutch and reverse brake solenoid valve command current is 750 mA or more.
    2. The high clutch and reverse brake solenoid valve current, which the TCM monitors, is 200 mA or less.
 
 
OBD-II DRIVE CYCLE PATTERN
Ignition switch: "ON" position (start the engine and keep it for 5 seconds or more)
 
 
PROBABLE CAUSES
  • Malfunction of the valve body assembly (Defective high clutch and reverse brake solenoid valve)
  • Damaged wiring harness and connectors
  • Malfunction of TCM
 
 
DIAGNOSIS
STEP 1. Check the following connector
  • CVT assembly connector
  • TCM connector
Check the terminals for a contact status problem and internal short circuit.
Is the check result normal?
Go to Step 2.
Repair the defective connector(s).
 
STEP 2. Check for open circuit or short to power supply in HRLS line between the CVT assembly connector and the TCM connector
Is the check result normal?
Go to Step 3.
Repair the wiring harness.
 
STEP 3. High clutch and reverse brake solenoid valve check
Refer to .
Is the check result normal?
Go to Step 4.
Replace the valve body assembly (Refer to ).
 
STEP 4. Symptom recheck after erasing diagnostic trouble code
Is the diagnostic trouble code stored?
Replace the TCM (Refer to ).
Intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunctions .).