2010 Porsche Panamera Turbo (970) V8-4.8L Turbo A L L Diagnostic Trouble Codes ( DTC ): P Code Charts Page 342
Fault setting conditions
- Reverse gear cannot be disengaged
Fault effects
- Gear held
- No gear preselection
- Transmission limp-home indication in instrument cluster control unit
Synchro Reverse Gear Not Engageable Or Gear Skip
P177B
Diagnosis information - PDK
Synchro reverse 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
Possible fault causes
- Hydraulics faulty (hydraulic control unit)
- Transmission faulty
Fault setting conditions
- Target gear Reverse gear, actual gear is disengaged before pressure adjusters 5/6 are activated
- 2nd gear is engaged instead of reverse 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
Synchro 1st Gear Not Disengageable
P177B
Diagnosis information - PDK
Synchro 1st gear not disengageable
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
Possible fault causes
- Hydraulics faulty (hydraulic control unit)
- Transmission faulty
Fault setting conditions
- 1st gear cannot be disengaged
Fault effects
- Gear held
- No gear preselection
- Transmission limp-home indication in instrument cluster control unit
Synchro 2nd Gear Not Disengageable