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Code P0841: Abnormality in Secondary Pressure Sensor Function
 
 
 
 
DIAGNOSTIC FUNCTION
TCM determines that the system is defective by monitoring the secondary pressure sensor.
 
 
DESCRIPTIONS OF MONITOR METHODS
The difference between the actual and target secondary pressures remains more than 0.675 MPa (97.9 psi) for five seconds while the vehicle is driven at constant speed.
 
 
MONITOR EXECUTION
  • Transmission range: "D"
  • Primary pulley speed: 306 r/min or more
  • Secondary pulley speed: 230 r/min or more
  • Actual pulley ratio change rate: 0.1 or less per second
  • Vehicle speed change rate: 50 km/h (31 mph) or less per five seconds
  • Accelerator pedal position change rate: 21 percents or less per five seconds
 
 
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
  • P0720: Malfunction of output speed sensor
  • P0746: Abnormality in hydraulic control system function
  • P0791: Malfunction of secondary pulley speed sensor
  • P0842: Malfunction of the secondary pressure sensor (low voltage)
  • P0843: Malfunction of the secondary pressure sensor (high voltage)
  • P0962: Malfunction of the line pressure solenoid valve (short to ground)
  • P0963: Malfunction of the line pressure solenoid valve (open circuit/ short to power supply)
  • P1607: Malfunction of the system power supply (low voltage)
  • U0100: CAN time-out error (Engine)
Sensor (The sensor below is determined to be normal)
  • Transmission range switch
  • Primary pulley speed sensor
  • Secondary pulley speed sensor
  • Output speed sensor
  • Line pressure solenoid valve
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Transmission range: "D"
  • Primary pulley speed: 306 r/min or more
  • Secondary pulley speed: 230 r/min or more
  • Actual pulley ratio change rate: 0.1 or less per second
  • Vehicle speed change rate: 50 km/h (31 mph) or less per five seconds
  • Accelerator pedal position change rate: 21 percents or less per five seconds
  • Voltage of battery: 10 volts or more
  • Voltage of battery: 16.5 volts or less
Judgment Criteria
  • The difference between the actual and target secondary pressures remains more than 0.675 MPa (97.9 psi) for five seconds.
 
 
OBD-II DRIVE CYCLE PATTERN
The vehicle is driven for at least 15 seconds without depressing the accelerator pedal and brake pedal while the selector lever is at "D" range.
 
 
PROBABLE CAUSES
  • Malfunction of the valve body assembly (Faulty secondary pressure sensor)
  • Malfunction of the transaxle assembly
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
  • MB991958: Scan Tool (M.U.T.-III Sub Assembly)
    • MB991824: Vehicles Communication Interface (V.C.I.)
    • MB991827: M.U.T.-III USB Cable
    • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
STEP 1. Hydraulic pressure test.
Refer to .
Is the check result normal?
Go to Step 2.
Repair the failure sections.
 
STEP 2. Check the following connector.
  • TCM connector
Check the terminals for a contact status problem and internal short circuit.
Is the check result normal?
Go to Step 3.
Repair the defective connector.
 
STEP 3. Voltage measurement at TCM connector (LPRS terminal).
(1) Connect the TCM connector.
(2) Drive the vehicle until the engine is warmed up.
(3) Transmission range: "P"
(4) Engine: Idling
(5) Measure the TCM connector side by backprobing.
(6) Measure the voltage between the TCM connector (LPRS terminal) and TCM connector (SGND terminal).
OK: approximately 0.84 volt
Is the check result normal?
Go to Step 4.
Refer to DTC P0842: Malfunction of the secondary pressure sensor (low voltage) , or DTC P0843: Malfunction of the secondary pressure sensor (high voltage) .
 
STEP 4. Using scan tool (M.U.T.-III), recheck the DTC.
Check again if the DTC is stored.
(1) Erase the DTC.
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Carry out a test drive with the OBD-II drive cycle pattern.
(4) Recheck the DTC.
Is DTC P0841 stored?
Go to Step 5.
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 5. CVT belt inspection.
Check the appearance of the CVT belt. (Refer to On-vehicle Service – CVT Belt Inspection)
Is the CVT belt normal?
Replace valve body assembly. (Refer to ).
Replace the transaxle assembly (Refer to ).