TSB : Synchro 3rd Gear Not Engageable Or Gear Skip

Details

P1780 Diagnosis information - PDK Synchro 3rd gear not engageable or gear skip Diagnostic conditions The control unit initially tests internal function sequences when the ignition is switched on (terminal 15). If they are OK, all diagnosable outputs are then tested and any faults are stored. - Ignition on - The following faults are not detected: P1731, P1732, P1733 or P1734 - The following faults are not detected: P1706 or P1707 - Alternative measure HSS3_OFF not active - Automatic gearshift without gear preselection is active Possible fault causes - Hydraulics faulty (hydraulic control unit) - Transmission faulty Fault setting conditions - Target gear 3rd gear, actual gear is disengaged before pressure adjusters 5/6 are activated - 1st gear is engaged instead of 3rd gear - No shift rod moves NOTE: The individual detection times are temperature-dependent (cold 2 s, warm 1 s) Fault effects - Gear held - Only gears 1, 2, 4 and 7 are possible - Transmission limp-home indication in instrument cluster control unit