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DTC P0843: Malfunction of the Secondary Pressure Sensor (high input)
 
 
 
 
DIAGNOSTIC FUNCTION
The TCM determines that the system is defective when the secondary pressure sensor output voltage is higher than a predetermined value.
 
 
DESCRIPTIONS OF MONITOR METHODS
All the conditions listed below remain for 5 seconds.
  • The temperature, which the transmission fluid temperature sensor detects, is more than -20°C (-4°F).
  • The target secondary pressure is 5.7 MPa (827 psi) or less.
  • The secondary pressure sensor output voltage is 4.7 V or more.
 
 
MONITOR EXECUTION
  • Voltage of battery: 10 volts or more.
  • Transmission fluid temperature: More than -20°C (-4°F).
 
 
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • P084A: Abnormality in primary pressure sensor function
  • P0966, P0967: Malfunction of secondary pressure solenoid valve
Sensor (The sensor below is determined to be normal)
  • Primary pressure sensor
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Voltage of battery: 10 volts or more.
  • Transmission fluid temperature: More than -20°C (-4°F).
Judgment Criteria
  • The secondary pressure sensor output voltage is 4.70 volts or more.
 
 
OBD-II DRIVE CYCLE PATTERN
Ignition switch: ON (start the engine and keep it for 10 seconds or more)
 
 
PROBABLE CAUSES
  • Malfunction of the valve body assembly (Faulty secondary pressure sensor)
  • Damaged wiring harness and connectors
  • Malfunction of TCM
 
 
DIAGNOSIS
STEP 1. Voltage measurement at CVT assembly connector (LPRS terminal)
(1) Measure the TCM connector side by backprobing.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between the CVT assembly connector (LPRS terminal) and body ground.
Is the voltage approximately 4.7 V or more?
Go to Step 2.
: Go to Step 4.
 
STEP 2. Check for short to power supply in LPRS line between the CVT assembly connector and the TCM connector
Is the check result normal?
Go to Step 3.
Repair the connector(s) or the wiring harness.
 
STEP 3. Check for short to power supply in signal line between the CVT assembly connector and the valve body harness connector (secondary pressure sensor line)
Refer to .
Is the check result normal?
Replace the valve body assembly. (Refer to )
Replace the valve body harness. (Refer to )
 
STEP 4. Voltage measurement at TCM connector (LPRS terminal)
(1) Drive the vehicle until the engine is warmed up.
(2) Measure the TCM connector side by backprobing.
(3) Selector lever position: N range.
(4) Engine: Idling
(5) Measure the voltage between the TCM connector (LPRS terminal) and body ground.
OK: approx. 1.67 - 1.69 V
Is the check result normal?
Go to Step 5.
Replace the valve body assembly. (Refer to )
 
STEP 5. Symptom recheck after erasing diagnostic trouble code
Is the diagnostic trouble code set?
Replace the TCM.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).