P179D Cooling Oil Valve Electrical Fail – Porsche

P179D Cooling Oil Valve Porsche (2)

P179D Porsche Cooling Oil Valve Electrical Fault


Symptoms of a faulty or failed Mechatronic unit can be poor gear selection or even no gear selection at all.

The following fault codes may have been recorded and could point to a faulty Mechatronic unit.

  • DTC P17D8 (Torque limitation because of clutch temperature) with symptom code 8040
  • DTC P0726 (RPM signal of engine control unit, implausible signal) with symptom code 7980
  • DTC P174B (Valve 4 in the sub-gearbox 1, electric fault) with symptom code 8027
  • DTC P174F (Valve 4 in the sub-gearbox 2, electric fault) with symptom code 8028
  • DTC P179C (Main pressure valve, electric fault) with symptom code 8029
  • DTC P179D (Coolant oil valve electrical fault) with symptom code 8030
  • DTC P174C (Partial transmission 1 valve 2 Electrical error ) with symptom code 8026
  • DTC P174A (Valve 3 in the sub-gearbox 1, electric fault) with symptom code 8939
  • DTC P174E (Valve 3 in the sub-gearbox 2, electric fault) with symptom code 8940
  • DTC P1740 (Clutch temperature monitoring) with symptom code 8031

If the above message shows, protective functions are activated to minimise or prevent damage occurring, but result in a loss of performance.

Gearbox fault possible no R-gear
Gearbox fault possible no R-gear

P179D Cooling Oil Valve Porsche

DTC P179D Cooling Oil Valve Porsche
DTC P179D00 Cooling Oil Valve – Electrical Fault Porsche Macan
Fault of Engine control system
Fault of Engine control system
DTC P0700 Fault in Transmission Control Unit
DTC P0700 Fault in Transmission Control Unit
P179D00 Cooling Oil Valve Porsche

P179D00 Cooling Oil Valve – Electrical Fault Porsche Macan

Technical Background

Poor internal contact area on circuit board will lead to faults. Oil additives can cause the plastic circuit plates to delaminate, causing contact loss.

VAG Porsche Audi Mechatronics Repair Kit  9A730190100 / 0B5398009F
VAG Porsche Audi Mechatronics Repair Kit 9A730190100 / 0B5398009F

Production Solution

Improved circuit board for mechatronics unit.

Component overview

Component overview of control mechanism for transmission
Component overview of control mechanism for transmission 2

cooling oil valve - Cooling Flow Solenoid (N471) 2
Cooling oil valve – Cooling Flow Solenoid (N471)

Removing and installing control mechanism for transmission

Removing control mechanism for transmission step 1-3
Removing control mechanism for transmission step 4-7

Adjusting shift forks and gear actuators

Adjusting shift forks and gear actuators
Adjusting shift forks and gear actuators



Replace Porsche Mechatronics Repair Kit 9A730190100 / 0B5398009F

Starting with the 2x larger protectors, which fit nicely on the larger two valves

Then I fitted the two cross shaped protectors as per the instructions

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