Articles
Real fault-code cases
Each case starts from one real diagnosis run in WrenchLane: the car, the fault codes, the causes it ranked and the checks worth doing first. Workshop and customer details are left out.
275 cases · Page 9 of 12
Browse by car make
- Volkswagen37
- Ford34
- Volvo29
- Audi20
- Mercedes-Benz20
- Toyota13
- Opel11
- Kia10
- Skoda10
- Saab9
- BMW8
- Peugeot8
- Renault6
- Citroën5
- Nissan5
- Jeep4
- Land Rover4
- Chevrolet3
- Honda3
- Hyundai3
- Mitsubishi3
- Vauxhall3
- Cadillac2
- Maxus2
- Mazda2
- Mini2
- Porsche2
- Seat2
- Subaru2
- Suzuki2
- Alfa Romeo1
- Fiat1
- Isuzu1
- Iveco1
- Jaguar1
- Lancia1
- Lexus1
- Maserati1
- MG1
-
Diagnosing a P0299 Underboost Fault on a 2015 BMW X5
A step-by-step diagnostic breakdown of a P0299 underboost fault code on a 2015 BMW X5, covering charge air leaks, vacuum issues, and turbocharger wear. -
Diagnosing a 2015 BMW X5 Shift Shudder
A 2015 BMW X5 presented with a second-gear shift shudder. Discover why the diagnostic path pointed away from the transmission to intake and cooling faults. -
Diagnosing a No-Start on a 1.2 PureTech with P0340 and P1632
A concrete diagnostic case study of a 2018 Citroen C4 Cactus 1.2 PureTech that cranks but won't start, featuring fault codes P0340 and P1632. -
Diagnosing a 2015 Astra J with P0014 and P0420
A 2015 Opel Astra J presented with a metallic rattle and codes P0014, P0118, P0420, and P2097. See how we diagnose the VVT and coolant sensor faults together. -
Diagnosing Multi-Cylinder Misfires Hiding Behind a P0301 Code
A 2013 Skoda Octavia presented with a P0301 code, but physical symptoms showed misfires on cylinders 1 and 3. Here is how to diagnose the root cause. -
Diagnosing a Silent P001900 on a 2017 Audi A5
Explore a real diagnostic case of a 2017 Audi A5 presenting a P001900 code with zero drivability symptoms, detailing testing paths for chains and sensors. -
Diagnosing P002300 on an Audi A5 3.0 TFSI
Learn how to accurately diagnose a P002300 code on a 2017 Audi A5. Explore the thermal impact on the N319 solenoid in the EA839 3.0 TFSI engine. -
Diagnosing P0101 on a Renault Megane III
A step-by-step look at diagnosing a P0101 MAF code and severe power loss on a Renault Megane III, from boost leaks to DPF backpressure. -
Diagnosing P010100 and a Sudden Stalling Condition on a 2009 Volkswagen Golf
A 2009 VW Golf loses power on the highway and stalls after starting with code P010100. See the diagnostic path to find the actual physical root cause. -
Diagnosing P0299 Alongside an AdBlue Fault
A concrete diagnostic case of a 2016 diesel with a P0299 underboost code and an AdBlue fault, exploring charge air leaks, VNT issues, and DPF blockage. -
Diagnosing P0299 on a 2019 SKODA Octavia III 2.0 TDI
A step-by-step diagnostic breakdown of a P0299 underboost code on a 2019 SKODA Octavia III 2.0 TDI, covering boost leaks, VNT seizure, and vacuum faults. -
Diagnosing P0299 on a 2009 Volvo XC60
A 2009 Volvo XC60 logs a P0299 underboost code. We break down the diagnostic paths, from charge pipe leaks and vacuum valves to fuel filter starvation. -
Diagnosing a P0420 on a 2011 Honda CR-V
A 2011 Honda CR-V presented with a P0420 fault code. We break down the diagnostic path, exploring catalyst degradation, secondary O2 sensors, and exhaust leaks. -
Diagnosing a P0420 on a 2012 Ford Focus III
A breakdown of a P0420 diagnosis on a 2012 Ford Focus III, exploring catalytic converter degradation, exhaust leaks, and a hidden EVAP purge valve issue. -
Diagnosing P0420 and C1201 on a 2005 Toyota Yaris II
A real diagnostic case study of a 2005 Toyota Yaris II with P0420 and C1201 codes, covering structured testing for catalysts, exhaust leaks, and O2 sensors. -
Diagnosing a P164D00 Code on a 2013 VW Tiguan
A 2013 Volkswagen Tiguan presented a P164D00 code with low oil pressure after five minutes of driving. We explore the top four probable causes. -
Diagnosing P2002 and P20EE with a Countdown
A 2016 diesel presented with P2002, P20EE, and a 250-mile no-start countdown. See how DPF backpressure and DEF dosing failures connect in this diagnostic case. -
Diagnosing P2002 on a 2020 Ford Transit Connect II
A detailed look at diagnosing code P2002 on a 2020 Ford Transit Connect II, exploring DPF saturation, sensor failures, and exhaust leaks. -
Diagnosing Dual-Fuel Misfires on a Lancia Ypsilon
A complete diagnostic breakdown of P0301 and P0300 misfire codes on a dual-fuel 2011 Lancia Ypsilon. Explore how LPG impacts ignition and injection systems. -
P0011 on a SKODA Fabia III: Diagnosing a 4th Gear Knock
A 2017 SKODA Fabia III presented with a P0011 code and a specific knock in fourth gear. We break down the diagnostic path from dirty oil to a faulty phaser. -
Diagnosing a severe knock and P030000 in a Volvo XC90 II
A diagnostic case study of a 2016 Volvo XC90 II presenting with a severe knocking sound and a P030000 misfire code, tracing fuel system and mechanical faults. -
Diagnosing 14 Fault Codes on a 2016 VW Tiguan
A 2016 VW Tiguan presented with 14 fault codes and intermittent ABS, ESP, and tire pressure warnings. See how to trace this back to voltage and gateway issues. -
Diagnosing Airbag Code B0029 on a 2007 Isuzu D-Max I
A step-by-step diagnostic breakdown for fault code B0029 on a 2007 Isuzu D-Max I. Learn how to test high resistance in the SRS airbag system. -
Diagnosing Dual Rear Sensor Codes on a Volvo V40
A 2012 Volvo V40 presented with codes P170181, C003A07, and C003707. See the step-by-step diagnostic path for shared ABS circuit failures.