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DTC P0840: Malfunction of Secondary Pressure Sensor
 
 

 
 
 
 
DIAGNOSTIC FUNCTION
TCM conducts fault detection by monitoring the output voltage of the secondary pressure sensor.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • The status with the fluid temperature of -20°C (-4°F) or more and with the secondary pressure sensor voltage of 4.69 volts or more continues for 5 seconds.
  • The status with the fluid temperature of -20°C (-4°F) or more and with the secondary pressure sensor voltage of 0.09 volt or less continues for 5 seconds.
 
 
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)
  • P0740: Malfunction of lockup solenoid valve
  • P0745: Malfunction of line pressure solenoid valve
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
LOGIC FLOW CHARTS (Monitor Sequence-Input Rationality-low)
 
 
LOGIC FLOW CHARTS (Monitor Sequence-Input Rationality-high)
 
 
DTC SET CONDITIONS
Judgment Criteria
  • Secondary pressure sensor voltage [transmission fluid temperature: more than -20°C (-4°F)]: 4.69 volts or more. (5 seconds)
  • Secondary pressure sensor voltage [transmission fluid temperature: more than -20°C (-4°F)]: 0.09 volt or less. (5 seconds)
 
 
OBD-II DRIVE CYCLE PATTERN
Ignition switch: ON (start the engine and keep it for 10 seconds or more)
 
 
PROBABLE CAUSES
  • Malfunction of valve body assembly (Faulty secondary pressure sensor)
  • Damaged wiring harness and connectors
  • Malfunction of TCM
 
 
DIAGNOSIS
STEP 1. Scan tool data list
  • Item 4: Secondary pressure sensor signal (Refer to Data List Reference Table .)
Is the check result normal?
Intermittent malfunction
Go to Step 2.
 
STEP 2. Check the following connector:
  • B-120 CVT assembly connector
  • C-130 TCM connector
  • A-16 Intermediate 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. Check for open circuit and short to ground in the wiring harness between the TCM connector and the CVT assembly connector.
  • Between C-130 TCM connector (terminal No.39) and B-120 CVT assembly connector (terminal No.7)
  • Between C-130 TCM connector (terminal No.48) and B-120 CVT assembly connector (terminal No.19)
  • Between C-130 TCM connector (terminal No.49) and B-120 CVT assembly connector (terminal No.5)
Is the check result normal?
Go to Step 4.
Repair the wiring harness.
 
STEP 4. Symptom recheck after replacing the valve body assembly
Is the check result normal?
The procedure is complete.
Replace TCM.