Code No. P285A:
Auxiliary Gearbox Gear 2 Incorrect Ratio
DIAGNOSTIC FUNCTION
The CVT-ECU determines that the system is defective when the auxiliary gearbox remains
the gear ratio is abnormal although the ECU commands the 2nd gear.
JUDGEMENT CRITERIA
- If all of the conditions below are satisfied while the vehicle is being driven,
the CVT-ECU determines that the gear ratio is abnormal.
- Deceleration ratio remains less than -0.05 G for 0.2
seconds.
- The ECU commands the 2nd gear to the auxiliary gearbox.
- The actual gear ratio of the auxiliary gearbox deviates by ±50% or
more from the 2nd gear ratio (1,000) for 0.2 seconds.
- If all of the conditions below are satisfied while the vehicle is being driven,
the CVT-ECU determines that the gear ratio is abnormal.
- The ECU commands the 2nd gear to the auxiliary gearbox.
- The actual gear ratio of the auxiliary gearbox deviates by ±10% or
less from the 1st gear ratio (1.821) for 0.5 seconds.
PROBABLE CAUSES
- Malfunction of the CVT assembly (Faulty low brake solenoid valve or valve
body assembly)
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STEP 1. Check the following connector
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Check the terminals for a contact status problem and internal short circuit.
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Q.
Is the check result normal?
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Go to Step 2.
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Repair the defective connector.
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STEP 2. Measure the output wave pattern of the low brake solenoid
valve at CVT-ECU connector (LBLS terminal).
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(1)Connect the CVT assembly connector.
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(2)Selector lever position: D range.
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(3)Drive at a constant speed of approx. 20 km/h (auxiliary gearbox: at 2nd
gear)
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(4)Connect an oscilloscope, and measure the voltage between CVT-ECU connector LBLS
terminal and body earth. OK: A wave pattern such as the one shown on (Check
Procedure Using an Oscilloscope) should be output, and the maximum value should be 11 V or more
and the minimum value should be 1 V or less. There should be no noise in the output wave pattern.
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Q.
Is the check result normal?
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Go to Step 3.
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Refer to diagnosis code No.P0973: Low Brake Solenoid Valve (short to earth) ,
or diagnosis code No.P0974: Low Brake Solenoid Valve (open circuit/short to power supply) .
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STEP 3. Symptom recheck after erasing diagnosis code
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch to the LOCK (OFF) position, and then wait for one minute.
Then drive the vehicle until the engine has been warmed up.
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(3)Check if the diagnosis code is stored.
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Q.
Is the diagnosis code stored?
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Replace the CVT assembly.
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Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunctions .).
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