Code No. P2858: Auxiliary Gearbox Gear 2 Incorrect Ratio Run-up
DIAGNOSTIC FUNCTION
The CVT-ECU determines that the system is defective when the auxiliary gearbox remains at incorrect ratio although the ECU commands the 2nd gear.
JUDGEMENT CRITERIA
- While the vehicle is being driven, the actual gear ratio of the auxiliary gearbox remains more than 2.232 for two seconds although the ECU commands the 2nd gear.
PROBABLE CAUSES
- Malfunction of the CVT assembly (Faulty high clutch and reverse 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 high clutch and reverse brake solenoid valve at CVT-ECU connector (HRLS 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 HRLS 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.P0976: High Clutch and Reverse Brake Solenoid Valve (short to earth) , or diagnosis code No.P0977: High Clutch and Reverse 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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