Code No. P0840: Malfunction of Secondary Pressure Sensor

DIAGNOSTIC FUNCTION

CVT-ECU conducts fault detection by monitoring the output voltage of the secondary pressure sensor.

JUDGMENT CRITERIA

The status with the fluid temperature of -20°C or more and with the secondary pressure sensor voltage of 4.69 V or more continues for 5 seconds.
The status with the fluid temperature of -20°C or more and with the secondary pressure sensor voltage of 0.09 V or less continues for 5 seconds.

PROBABLE CAUSES

Malfunction of valve body assembly (Faulty secondary pressure sensor)
Damaged wiring harness and connectors
Malfunction of CVT-ECU

DIAGNOSTIC PROCEDURE

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

Item 04: Secondary pressure sensor signal (Refer to Service Data Reference Table .)

Q. Is the check result normal?

	Intermittent malfunction

	Go to Step 2.

STEP 2. Check the following connector:

B-118 CVT assembly connector
C-33 CVT-ECU connector
A-10 Intermediate connector

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

Q. Is the check result normal?

	Go to Step 3.

	Repair the defective connector.

STEP 3. Check for open circuit and short to earth in the wiring harness between the CVT-ECU connector and the CVT assembly connector.

Between C-33 CVT-ECU connector (terminal No. 39) and B-118 CVT assembly connector (terminal No. 7)
Between C-33 CVT-ECU connector (terminal No. 48) and B-118 CVT assembly connector (terminal No. 19)
Between C-33 CVT-ECU connector (terminal No. 49) and B-118 CVT assembly connector (terminal No. 5)

Q. Is the check result normal?

	Go to Step 4.

	Repair the wiring harness.

STEP 4. Symptom recheck after replacing the valve body assembly

Q. Is the check result normal?

	The inspection is complete.

	Replace CVT-ECU.