P0840

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)

- P0746: Abnormality in hydraulic control system function
- P0841: Abnormality in line pressure sensor function
- P0868: Secondary pressure drop
Sensor (The sensor below is determined to be normal)

- Not applicable

LOGIC FLOW CHARTS (Monitor Sequence)





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

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list

- Item 4: Secondary pressure sensor signal (Refer to Data List Reference Table Data List Reference Table .)

Q. Is the check result normal?

YES Intermittent malfunction
NO Go to Step 2.
STEP 2. Check the following connector:

- B-08 CVT assembly connector
- C-40 TCM connector
- A-09 Intermediate connector

Check the terminals for a contact status problem and internal short circuit.

Q. Is the check result normal?

YES Go to Step 3.
NO 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-40 TCM connector (terminal No.39) and B-08 CVT assembly connector (terminal No.7)
- Between C-40 TCM connector (terminal No.48) and B-08 CVT assembly connector (terminal No.19)
- Between C-40 TCM connector (terminal No.49) and B-08 CVT assembly connector (terminal No.5)

Q. Is the check result normal?

YES Go to Step 4.
NO Repair the wiring harness.
STEP 4. Symptom recheck after replacing the valve body assembly

Q. Is the check result normal?

YES The procedure is complete.
NO Replace TCM.