Code No. P0843:
Malfunction of Secondary Pressure Sensor (high input)
DIAGNOSTIC FUNCTION
The CVT-ECU determines that the system is defective when the secondary pressure sensor output
voltage is higher than a predetermined value.
JUDGEMENT CRITERIA
All the conditions listed below remain for 5 seconds.
- The temperature, which the CVT fluid temperature sensor detects, is higher
than -20°C.
- The target secondary pressure is 5.7 MPa or less.
- The secondary pressure sensor output voltage is 4.7 V or more.
PROBABLE CAUSES
- Malfunction of the valve body assembly (Faulty secondary pressure sensor)
- Damaged wiring harness and connectors
- Malfunction of CVT-ECU
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STEP 1. Voltage measurement at CVT assembly connector (LPRS
terminal)
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(1)Measure the CVT-ECU connector side by backprobing.
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(2)Turn the ignition switch to the "ON" position.
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(3)Measure the voltage between the CVT assembly connector (LPRS terminal) and body
earth.
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Q.
Is the voltage approximately 4.7 V or more?
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 Go to Step 2
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NO  : Go to Step 4
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STEP 2. Check for short to power supply in LPRS line between the CVT
assembly connector and the CVT-ECU connector
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Q.
Is the check result normal?
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Go to Step 3
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 Repair the connector(s) or the wiring harness.
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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)
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Refer to  .
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Q.
Is the check result normal?
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Replace the valve body assembly (Refer to ).
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Replace the valve body harness (Refer to ).
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STEP 4. Voltage measurement at CVT-ECU connector (LPRS terminal)
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(1)Drive the vehicle until the engine is warmed up.
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(2)Measure the CVT-ECU connector side by backprobing.
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(3)Selector lever position: N
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(5)Measure the voltage between the CVT-ECU connector (LPRS terminal) and body earth.
OK: approx. 1.67 -
1.69 V
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Q.
Is the check result normal?
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Go to Step 5
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Replace the valve body assembly. (Refer to )
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STEP 5. Symptom recheck after erasing diagnosis code
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Q.
Is the diagnosis code set?
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Replace the CVT-ECU.
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Intermittent malfunction.
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