Audi Diagnostic Trouble Codes
OBD2 fault codes seen on Audi vehicles, with what each code means and the Audi models it shows up on. Each code's page has its typical repair cost range.
Own a Audi? The free Skanyx app reads these fault codes from your car and rates how urgent each one is.
Get the free appEmissions
Camshaft Position B - Timing Over-Advanced or System Performance (Bank 1)
- Audi A4 • 2008-2011
The first and second generation of the chain-driven EA888 engine (1.8 and 2.0 TFSI, built about 2007 to 2011)…
"B" Camshaft Position - Timing Over-Retarded (Bank 1)
- Audi A4 • 2008-2024
Camshaft adjusters are driven by engine oil pressure, so check the oil level, its condition and the service…
"A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)
- Audi A6 • 2008-2018
The A6 3.0 TFSI is a supercharged V6, so it has a bank 2 and can set P0021. A bank 2 intake camshaft adjuster…
"A" Camshaft Position - Timing Retarded (Bank 2)
- Audi A6 • 2009-2018
Bank 2 exists only on V engines, so on an A6 this code points to a V engine such as the supercharged 3.0 TFSI…
Intake Air Temperature Sensor 2 Circuit High
- Audi A4 • 2008-2024
On turbocharged A4 engines the charge air temperature sensor can sit in the charge air pipe or be built into…
Manifold Absolute Pressure/Barometric Pressure Circuit Low
- Audi A4 • 2008-2024
On the A4, VCDS lists P0107 under the same G71 and F96 signal low fault text as on the Golf, so the same…
O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
- Audi A4 • 2008-2024
Confirm petrol versus diesel, since the sensor location differs.
O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)
- Audi A4 • 2008-2015
Higher than normal oil consumption on the first-generation EA888 2.0 TFSI was seen mostly in longitudinal…
O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
- Audi A4 • 2008-2015
Higher than normal oil consumption on the first-generation EA888 2.0 TFSI was seen mostly in longitudinal…
O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)
- Audi A4 • 2006-2024
On the B7 and B8 A4 2.0 TFSI (EA113 in the B7, EA888 in the B8), check fuel trims and injector condition…
O2 Sensor Circuit Slow Response (Bank 1, Sensor 2)
- Audi A4 • 2008-2016
On the B8 A4 with the 2.0 TFSI, P0139 refers to the downstream sensor on bank 1.
O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 2)
- Audi A4 • 2008-2015
Higher than normal oil consumption on the first-generation EA888 2.0 TFSI was seen mostly in longitudinal…
O2 Sensor Circuit Malfunction (Bank 2, Sensor 2)
- Audi A6 • 2004-2009
The 3.2 V6 FSI in the C6-generation A6 has four oxygen sensors: two ahead of the catalytic converters and two…
O2 Sensor Circuit Low Voltage (Bank 2, Sensor 2)
- Audi A6 • 2004-2009
On the 3.2 V6 FSI each bank's three cylinders feed their own cast-iron exhaust manifold, and the bank 2…
O2 Sensor Circuit High Voltage (Bank 2, Sensor 2)
- Audi A6 • 2004-2009
The 3.2 V6 FSI runs separate oxygen sensing for each bank, so a rich condition on the bank 2 cylinders (4-6)…
O2 Sensor Circuit Slow Response (Bank 2, Sensor 2)
- Audi A6 • 2004-2009
The downstream G131 sensor is how the engine computer judges the bank 2 catalyst on the 3.2 V6 FSI. If it…
O2 Sensor Circuit No Activity Detected (Bank 2, Sensor 2)
- Audi A6 • 2004-2009
On the 3.2 V6 FSI the bank 2 post-catalyst sensor is G131 and the bank 1 one is G130. With no activity from…
O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 2)
- Audi A6 • 2004-2009
Audi's service training for the A6 3.2 V6 FSI lists a separate heater for each of its four oxygen sensors…
Exhaust Gas Recirculation (EGR) Flow Insufficient
- Audi A4 • 2005-2024
Exhaust Gas Recirculation Flow Excessive Detected
- Audi A4 • 2008-2015
The B8 A4 2.0 TDI uses the EA189 engine, so the same EGR deposit pattern as on the Golf TDI applies.
Exhaust Gas Recirculation Control Circuit Malfunction
- Audi A4 • 2008-2016
Engine covered (diesel): 2.0 TDI of the A4 B8. P0403 reports a fault in the circuit that controls the EGR…
Exhaust Gas Recirculation Control Circuit Range/Performance
- Audi A4 • 2008-2015
The B8 A4 2.0 TDI uses the EA189 engine, so the same EGR deposit pattern as on the Golf TDI applies.
Exhaust Gas Recirculation Sensor "A" Circuit Low
- Audi A4 • 2008-2024
On the A4 2.0 TDI the code refers to the position sensor of the EGR valve in the same way, so read its live…
Exhaust Gas Recirculation Sensor "A" Circuit High
- Audi A4 • 2008-2024
On the A4 TDI the same first check applies: the EGR valve connector and wiring, before replacing the valve.
Secondary Air Injection System Malfunction
- Audi A4 • 2005-2020
If the pump shows signs of moisture damage, check the combination valve at the same time, because a valve…
Secondary Air Injection System Incorrect Flow Detected
- Audi A3 • 2005-2024
Check the secondary air pump connections and hoses for water damage and cracks before replacing the pump.
Warm Up Catalyst Efficiency Below Threshold (Bank 1)
- Audi A6 • 2005-2024
On a V6 A6, P0421 refers to the bank that contains cylinder 1. Fix any misfire or fuel-trim codes before…
Main Catalyst Efficiency Below Threshold (Bank 1)
- Audi A6 • 2011-2018
On the C7 A6 with the 3.0 TFSI, a V6 with two cylinder banks, P0422 refers to the catalyst on bank 1 only.
Catalyst System Efficiency Below Threshold (Bank 2)
- Audi A4 • 2005-2015
Four-cylinder A4 models have a single cylinder bank and cannot set a Bank 2 code. P0430 applies to the V6…
Warm Up Catalyst Efficiency Below Threshold (Bank 2)
- Audi A6 • 2005-2018
On the Audi A6 with the supercharged 3.0 TFSI V6, P0431 points to the Bank 2 pre-cat, meaning the bank that…
Main Catalyst Efficiency Below Threshold (Bank 2)
- Audi A6 • 2011-2018
On the Audi A6 3.0 TFSI (EA837) V6 each bank has its own catalysts, and P0432 points to the Bank 2 main cat…
Heated Catalyst Temperature Below Threshold (Bank 2)
- Audi A6 • 2019-2024
The A6 with a V6 engine has two cylinder banks, so a Bank 2 catalyst code can apply to it.
Diesel Particulate Filter Efficiency Below Threshold (Bank 2)
- Audi Q7 V8 and V12 TDI • 2007-2015
- Audi A8 4.2 TDI • 2005-2010
O2 Sensor Signal Biased/Stuck Lean (Bank 1, Sensor 1)
- Audi A4 • 2008-2024
Smoke-test the intake for unmetered air before replacing the sensor.
Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 4)
- Audi A4 2.0 TDI • 2008-2015
On some B8 A4 2.0 TDI engines outside North America (engine code CAGA), the exhaust temperature readings in…
Ignition
Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)
- Audi A6 • 2005-2018
The A6 was sold with the supercharged 3.0 TFSI V6 in both the C6 and C7 generations. On an engine with…
Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)
- Audi A6 • 2005-2018
P0018 is a bank 2 timing fault, so it only applies to V-engines. In the A6 that means the supercharged 3.0…
Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor B)
- Audi A6 • 2008-2018
On the 3.0 TFSI (EA837) a bank 2 timing code can come from the camshaft adjuster solenoid or from the timing…
Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)
- Audi A4 • 2008-2024
Inspect the knock sensor harness for chafing and a short to a 12 V wire before replacing the sensor.
Crankshaft Position Sensor "A" Circuit Range/Performance
- Audi A6 • 2005-2018
Volkswagen Group software reports this code as "Crankshaft Position Sensor (G28): Missing Tooth". Ross-Tech…
Camshaft Position Sensor Circuit Malfunction
- Audi A4 • 2008-2024
If this code appears together with P0016, inspect the timing chain and its tensioner as well as the sensor or…
Camshaft Position Sensor "A" Circuit Range/Performance
- Audi A4 • 2005-2024
The 2.0 TFSI in the B7 A4 (EA113) drives its camshafts with a timing belt, while the EA888 2.0 TFSI in the B8…
Camshaft Position Sensor "A" Circuit Low Input (Bank 1 or Single Sensor)
- Audi A4 • 2008-2024
If this code appears together with P0011 or P0012, check the cam adjuster and its oil control valve as well…
Camshaft Position Sensor "A" Circuit High Input (Bank 1 or Single Sensor)
- Audi A4 • 2008-2024
Ignition Coil E Primary/Secondary Circuit Malfunction
- Audi S5 Coupe (B8, 4.2 FSI V8) • 2007-2012
The 4.2 FSI V8 is direct-injected, and its other well-known misfire cause, carbon building up on the intake…
Ignition Coil F Primary/Secondary Circuit Malfunction
- Audi S5 Coupe (B8, 4.2 FSI V8) • 2007-2012
The 4.2 FSI V8 is direct-injected, and its other well-known misfire cause, carbon building up on the intake…
Ignition Coil G Primary/Secondary Circuit Malfunction
- Audi S5 Coupe (B8, 4.2 FSI V8) • 2007-2012
The 4.2 FSI V8 is direct-injected, and its other well-known misfire cause, carbon building up on the intake…
Ignition Coil H Primary/Secondary Circuit Malfunction
- Audi S5 Coupe (B8, 4.2 FSI V8) • 2007-2012
The 4.2 FSI V8 is direct-injected, and its other well-known misfire cause, carbon building up on the intake…
Camshaft Position Sensor "B" Circuit (Bank 1)
- Audi A6 3.2 FSI V6 • 2005-2011
On VW Group cars the bank 1 "B" camshaft sensor is G300 in Ross-Tech's wiki. Its P0366 entry for that sensor…
Fuel System
Turbocharger/Supercharger Boost Control "A" Circuit Range/Performance
- Audi A4 • 2016-2019
The B9 A4 with the 2.0 TFSI petrol uses the third-generation EA888, whose turbo wastegate is moved by an…
Mass or Volume Air Flow Circuit Low Input
- Audi A4 • 2008-2015
On the B8 A4 2.0 TFSI, the element loses sensitivity when carbon and oil contaminate it. Long-term fuel…
Mass or Volume Air Flow Circuit High Input
- Audi A4 • 2008-2024
VW group fault documentation lists the same causes for the Audi A4: a short circuit in the wiring or…
Mass or Volume Air Flow Circuit Intermittent
- Audi A4 • 1997-2024
Audi uses the same Volkswagen Group fault list, so VCDS reports P0104 as 16488 against the G70 air mass meter…
System Too Lean (Bank 1)
- Audi A4 • 2008-2015
On the 2.0 TFSI A4 (B8, 2008-2015), look for air leaking in after the MAF sensor: the crankcase ventilation…
System Too Rich (Bank 1)
- Audi A4 • 2008-2024
A leaking injector can push Bank 1 rich, while a worn high-pressure fuel pump usually causes lean running or…
Fuel Trim Malfunction (Bank 2)
- Audi A6 • 2011-2018
The C7 A6 3.0 TFSI (EA837) is a supercharged V6 with its two cylinder banks on the left and right of the…
System Too Lean (Bank 2)
- Audi A4 • 2005-2024
Four-cylinder TFSI A4 models are single-bank and set P0171; P0174 shows up on the V6 cars such as the 3.2 FSI.
System Too Rich (Bank 2)
- Audi A6 • 2011-2018
On the C7 A6 with the 3.0 TFSI, a purge valve stuck open adds fuel vapour to the intake and pushes the fuel…
Turbocharger/Supercharger Boost Sensor "A" Circuit Low
- Audi A3 • 2009-2024
Volkswagen group diagnostics log P0237 as "Manifold Pressure / Boost Sensor (G31): Signal too Low" and list…
Intake Manifold Runner Control Stuck Open (Bank 1)
- Audi A4 • 2008-2016
The A4 B8 with the 2.0 TFSI (EA888) has the same kind of variable intake manifold with charge movement flaps…
Intake Manifold Runner Control Stuck Closed (Bank 1)
- Audi A3 • 2004-2024
Check the part number on the manifold you remove before ordering a replacement.
Intake Manifold Runner Control Stuck Closed (Bank 2)
- Audi A6 • 2005-2008
- Audi A4 • 2005-2008
Intake Manifold Runner Position Sensor/Switch Circuit Range/Performance (Bank 1)
- Audi A3 • 2008-2013
The A3 8P with the 2.0 TDI common-rail engine shares its intake manifold and flap arrangement with the Golf…
System Too Lean at Idle (Bank 1)
- Audi A3 • 2005-2024
On VAG petrol engines Ross-Tech lists leaking or blocked injectors, an intake air leak after the air mass…
Cooling System
Electrical
Engine Oil Temperature Sensor
- Audi A4 • 2005-2024
Read the fault with VCDS rather than a generic scan tool if you can, because it names the sensor and tells…
Engine Oil Temperature Sensor Range/Performance
- Audi A4 • 2005-2024
Audi uses the same G266 oil level and temperature sender as other VW Group cars; VCDS shows it as fault…
Engine Overspeed Condition
- Audi A3 • 2008-2024
The A3 uses the DSG/S tronic gearbox family it shares with the Golf.
Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
- Audi A4 • 2005-2024
On the A4, inspect the knock sensor harness and connector before replacing the sensor.
Glow Plug / Heater Circuit "A" Malfunction
- Audi A4 TDI • 2004-2016 (B7 and B8, 2.0 TDI and 3.0 TDI)
On the A4 TDI, P0380 usually points to the glow plug control module, a glow plug or the wiring. A glow plug…
Brake Switch "A"/"B" Correlation
- Audi A4 • 2008-2024
P0504 sets when the two brake switch signals disagree, so check that the switch plunger moves freely and the…
ECM/PCM Processor Fault
- Audi A4 • 2005-2024
Glow Plug Control Module Circuit
- Audi A4 TDI • 2004-2019
Cylinder 1 Glow Plug Circuit
- Audi A4 TDI • 2004-2019
VW group documentation uses the same cylinder 1 glow plug (Q10) fault text on the Audi A4 TDI: check the…
Cylinder 2 Glow Plug Circuit
- Audi A4 TDI • 2004-2019
Audi diesels fall under the same VAG fault entry: Ross-Tech's entry for VAG's own glow plug fault (P161B)…
Cylinder 3 Glow Plug Circuit
- Audi A4 TDI • 2004-2019
Audi diesels fall under the same VAG fault entry: Ross-Tech's entry for VAG's own glow plug fault (P161C)…
Cylinder 4 Glow Plug Circuit
- Audi A4 TDI • 2004-2019
For Volkswagen Group cars such as the A4 TDI, Ross-Tech's description of the cylinder 4 glow plug fault names…
Intake Manifold Runner Control Circuit/Open (Bank 1)
- Audi A4 • 2005-2024
On the A4, P2008 has the same meaning: an open circuit in the intake manifold runner control. Before agreeing…
Misfire
Random/Multiple Cylinder Misfire Detected
- Audi A4 • 2008-2024
The A4 shares the EA888 family with the Golf, and on its direct-injection 2.0 TFSI engines carbon on the…
Cylinder 1 Misfire Detected
- Audi A4 • 2008-2024
The A4 shares the EA888 TSI family with VW, so on its direct-injection 2.0 TFSI a cylinder 1 misfire can come…
Cylinder 2 Misfire Detected
- Audi A4 • 2005-2024
Direct-injection engines such as the 2.0 TFSI can build up carbon on the intake valves, because the fuel…
Cylinder 6 Misfire Detected
- Audi A6 • 2011-2018
C7 A6 with the 3.0 TFSI supercharged V6 can set P0306 from a cylinder 6 coil, spark plug or injector fault.
Cylinder 7 Misfire Detected
- Audi S5 Coupe (B8, 4.2 FSI V8) • 2007-2012
The 4.2 FSI V8 injects fuel directly into the cylinders, so no fuel washes over the intake valves and carbon…
Cylinder 8 Misfire Detected
- Audi S5 Coupe (B8, 4.2 FSI V8) • 2007-2012
Because the 4.2 FSI injects fuel straight into the cylinders, its intake valves collect carbon that no fuel…
EVAP System
Evaporative Emission Control System Malfunction
- Audi A4 • 2005-2015
On the 2.0 TFSI A4 (B7 and B8), start with the fuel cap and the EVAP hoses and connectors near the engine…
Evaporative Emission Control System Vent Control Circuit Open
- Audi A4 • 2005-2024
On A4s with leak-detection hardware, the EVAP vent valve at the canister is the usual failure for P0447, and…
Evaporative Emission Control System Vent Control Circuit Shorted
- Audi A4 • 2005-2024
On A4s with leak-detection hardware, the vent valve harness runs under the car, and P0448 often follows…
Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
- Audi A4 • 2005-2024
On A4s with leak-detection hardware, the harness routing on the saloon differs slightly from the Golf. Check…
Evaporative Emission Control System Pressure Sensor Intermittent
- Audi A4 • 2005-2024
On A4s with leak-detection hardware, the fuel tank pressure sensor is fitted at the fuel pump module, reached…
Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)
- Audi A4 • 2005-2024
The A4 cap, like the Golf's, must be turned until it clicks, and a cap not seated properly at refuelling is…
Transmission
Input/Turbine Speed Sensor Circuit Malfunction
- Audi A4 • 2005-2024
Front-wheel-drive A4 models were sold with the Multitronic CVT, which is not compatible with quattro, so…
Torque Converter Clutch Circuit Performance/Stuck Off
- Audi A4 • 2005-2024
Only A4s with a torque-converter automatic (tiptronic) can set P0741. The B8, for example, offered a ZF…
Related posts
Diagnose your Audi with Skanyx
Connect a standard Bluetooth OBD2 adapter to your Audi, scan for codes, and get AI-powered diagnostics with severity ratings and repair cost estimates.
Download Skanyx