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P0781 1-2 Shift

AutoHex Online Help: Hyundai GENESIS(BH) 2010
Component Location
General Description

1-2 Shift valve is shift to oil-pathway in order to maintain over the 2nd gear shifting. 1-2 Shift valve function is deliver oil-perssure to clutch that over the 2nd grar operation element, When 1-2 shifting.



DTC Description

TCM set this code If the rear gear ratio that calculated by Engine speed/Output speed and the target gear ratio that calculated by compounding of solenoid valves are not match.

DTC Detecting Condition

Item

Detecting Condition

Possible Cause

DTC Strategy

Valve Stuck

Valve-body

A/T Assembly

1: The detection criteria of S3 ON fail and 1-2 shift valve SP stick is the same, so if this detection criteria is fullfilled, then both S3 ON DTC and 1-2 shift valve DTC are stored. But if present gear judged 1st and current gear 2nd before this detection criteria is fullfilled, then only the DTC of 1-2 shift valve SP stick is stored.

S3 ON fail and 1-2 shift valve SP stick can be distinguished by what present gear is made at current gear 2nd(Not 2nd EB).S3 ON fail : Current gear 2nd then present gear 2nd1-2 shift valve SP stick : Current gear 2nd then present gear 1st

Enable Conditions

10.2V < Battery voltage < 14V

Not error in system

CAN communication : normal.

Solenoid valve : normal

Threshold Value

Current gear 4th and Present gear 3rd

Current gear 5th and Present gear neutral

Diagnostic Time

Immediately

Fail Safe

1st and 2nd gear inhibit at Manual mode

* Only 1st and 2nd gear inhibit at Manual mode fail safe

After 2 driving cycle of above detection continuously

No up shift 4th, 5th and 6th

1-2 shift valve stick decision

? Not manual mode or

? Manual mode and speed < 80km/h

Diagnostic Circuit Diagram
Signal Waveform & Data

Fig 1) D Range-1st gear

Fig 2) D Range-2nd gear

Fig 3) Sports mode -1st gear

Fig 4) Sports mode -2nd gear

Fig 5) Sports mode -3rd gear

Fig 6) Sports mode -4th gear

Fig 7) Sports mode -5th gear

Fig 8) Sports mode -6th gear

Fig 9) Reverse