Hi - my mate has a 2.0L diesel Octavia iv 2023 hatchback which has the oil pressure warning light along with a couple of other error codes persistently returning despite clearing the codes several times and completing the following maintenance jobs as advised by different mechanics.

He has replaced the egr valve, oil pressure switch, oil pressure solenoid, wet oil belt ( along with checking and cleaning the oil strainer ), air flap actuator and both water pump c's. It's doing his absolute nut in so I've posted here in the hope that someone can offer any advice or suggestions. I have also included his obd11 log below. Personally it looks like to me as if there maybe an electrical issue but the local auto electrician couldn't find any issue. We both have no faith in our local main dealer after receiving the car overfilled with oil on one occasion after a service and noticing that the fuel filter had been drilled and a wrong screw fitted on another service occasion. Any pointers will be gratefully appreciated. Thanks.

OBDeleven vehicle history log

Date: 2025-08-15 19:42:47

VIN: TMBBJ********

Car:

Year: 2023

Body type: UNKNOWN

Engine: DTTA kW ( hp) l

Mileage: 114390 mi

---------------------------------------------------------------

01 Engine

System description: R4 2.0l TDI

Software number: 05L906022HK

Software version: 2088

Hardware number: 05L907309AA

Hardware version: H80

Faults:

P055F00 - Engine Oil Pressure Out of Range

Intermittent

Priority - 2

Malfunction frequency counter - 1

Unlearning counter - 40

km-Mileage - 183827 km

Engine speed - 1006.50 1/min

Normed load value - 28.2 %

Vehicle speed - 4 km/h

Coolant temperature - 75 °C

Intake air temperature - 24 °C

Ambient air pressure - 990 mbar

Voltage terminal 30 - 12.380 V

Dynamic environmental data - 209628395303202F0D37381D1BC34F7009E14FBE099E4F9700002CD80000

date - 2025-08-13 11:00:47

P023A00 - Charge Air Cooler Coolant Pump Control Circuit/Open

Intermittent

Priority - 2

Malfunction frequency counter - 20

Unlearning counter - 40

km-Mileage - 183824 km

Engine speed - 929.00 1/min

Normed load value - 18.0 %

Vehicle speed - 0 km/h

Coolant temperature - 89 °C

Intake air temperature - 39 °C

Ambient air pressure - 990 mbar

Voltage terminal 30 - 12.100 V

Dynamic environmental data - 209628448C03E844540B7D3E6E000001FB44560CD039530344B40F84

date - 2025-08-13 10:50:33

P06DA00 - Engine Oil Pressure Control Circuit/Open

Intermittent

Priority - 2

Malfunction frequency counter - 1

Unlearning counter - 40

km-Mileage - 183824 km

Engine speed - 823.00 1/min

Normed load value - 29.4 %

Vehicle speed - 0 km/h

Coolant temperature - 76 °C

Intake air temperature - 24 °C

Ambient air pressure - 990 mbar

Voltage terminal 30 - 12.020 V

Dynamic environmental data - 209628395303202F0D24381D15644F7009FA4FBE07A94F9700002CD80000

date - 2025-08-13 10:50:35

P26F400 - Coolant Pump "C" Control

Circuit/Open

Intermittent

Priority - 2

Malfunction frequency counter - 1

Unlearning counter - 40

km-Mileage - 183824 km

Engine speed - 865.50 1/min

Normed load value - 22.7 %

Vehicle speed - 0 km/h

Coolant temperature - 77 °C

Intake air temperature - 24 °C

Ambient air pressure - 990 mbar

Voltage terminal 30 - 11.980 V

Dynamic environmental data - 2096284484101644540B733E6E0000013A51D40DA144830DAC44B410D1

date - 2025-08-13 10:50:34

P06DB00 - Engine Oil Pressure Control Circuit Low

Intermittent

Priority - 2

Malfunction frequency counter - 1

Unlearning counter - 40

km-Mileage - 183824 km

Engine speed - 933.00 1/min

Normed load value - 20.8 %

Vehicle speed - 0 km/h

Coolant temperature - 76 °C

Intake air temperature - 24 °C

Ambient air pressure - 990 mbar

Voltage terminal 30 - 11.940 V

Dynamic environmental data - 209628395303202F0D6B381D18D24F70099B4FBE08994F9700002CD80000

date - 2025-08-13 10:50:33

P040100 - Exhaust Gas Recirc.Flow

Insufficient Detected

static

Priority - 2

Malfunction frequency counter - 28

Unlearning counter - 40

km-Mileage - 183803 km

Engine speed - 1922.50 1/min

Normed load value - 63.1 %

Vehicle speed - 52 km/h

Coolant temperature - 57 °C

Intake air temperature - 33 °C

Ambient air pressure - 980 mbar

Voltage terminal 30 - 13.060 V

Dynamic environmental data - 2096280846FD35446A048B0845FDC44472200044A61AF741D0FFC844CD2272

date - 2025-08-12 17:25:07

U041600 - Invalid Data Received From Vehicle Dynamics Control Module

Intermittent

Priority - 6

Malfunction frequency counter - 1

Unlearning counter - 35

km-Mileage - 183803 km

Engine speed - 1000.00 1/min

Normed load value - 19.2 %

Vehicle speed - 0 km/h

Coolant temperature - 35 °C

Intake air temperature - 35 °C

Ambient air pressure - 990 mbar

Voltage terminal 30 - 11.860 V

Dynamic environmental data - 20962352D90005416B200021160000

date - 2025-08-12 17:22:22

Has the oil pressure actually been tested by attaching a gauge in place of the sensor?

6 minutes ago, Warrior193 said:

Has the oil pressure actually been tested by attaching a gauge in place of the sensor?

No but we will look into finding someone who can perform this. Thanks for the suggestion.

Ok - just an update - we've solved the issue. As I suspected it was a fractured/broken wire which was causing all the issues. It's our belief that it was most probably caused by work that was done by the main dealer when changing a crankshaft sensor as the the issues started happening shortly after the car came back from them. Obviously this cannot be proven but at least we've sorted the problem. Happy days!!

Well done.