Possible causes – Air leak before catalytic converter – Faulty oxygen sensor– Faulty Catalytic Converter Tech notes As the code description implies the P0423 code means that the vehicle’s control module has detected that the three-way catalytic converter is not

Possible causes – Air leak before catalytic converter – Faulty oxygen sensor– Faulty Catalytic Converter Tech notes As the code description implies the P0424 code means that the vehicle’s control module has detected that the three-way catalytic converter is not

Possible causes – Battery defective– Loose or missing alternator drive belt– Faulty alternator– Open or short system voltage circuit Tech notes Higher than expected voltage problems are most likely caused by bad voltage regulator. The voltage regulator is part of

Possible causes – Blown Fuel Pump fuse– Open Fuel Pump Monitor Circuit– Faulty Fuel Pump Relay– Damaged ECM When is the code detected? The code will be set if an incorrect voltage on the control circuit of the fuel pump

Possible causes – Blown Fuel Pump fuse– Open Fuel Pump Monitor Circuit– Faulty Fuel Pump Relay– Damaged Engine Control Module (ECM) When is the code detected? The code will be set if a low voltage on the control circuit of

Possible causes – Blown Fuel Pump fuse– Open Fuel Pump Monitor Circuit– Faulty Fuel Pump Relay– Damaged Engine Control Module (ECM) When is the code detected? The code will be set if a low voltage on the control circuit of

Possible causes – Boost pressure sensor harness is open or shorted– Boost pressure sensor circuit poor electrical connection– Faulty boost pressure sensor– Faulty Turbo/Super Charger– Engine over temperature– Ignition misfire exceeds the calibrated threshold– Faulty Knock sensor (KS) When is

Possible causes – Boost pressure sensor harness is open or shorted– Boost pressure sensor circuit poor electrical connection– Faulty boost pressure sensor– Faulty Turbo/Super Charger– Engine over temperature– Ignition misfire exceeds the calibrated threshold– Faulty Knock sensor (KS) When is

Possible causes – Boost pressure sensor harness is open or shorted– Boost pressure sensor circuit poor electrical connection– Faulty boost pressure sensor– Faulty Turbo/Super Charger– Engine over temperature– Ignition misfire exceeds the calibrated threshold– Faulty Knock sensor (KS) When is

Possible causes – Boost pressure sensor harness is open or shorted– Boost pressure sensor circuit poor electrical connection– Faulty boost pressure sensor– Faulty Turbo/Super Charger– Engine over temperature– Ignition misfire exceeds the calibrated threshold– Faulty Knock sensor (KS) When is

Possible causes – Boost pressure sensor harness is open or shorted– Boost pressure sensor circuit poor electrical connection– Faulty boost pressure sensor– Faulty Turbo/Super Charger– Engine over temperature– Ignition misfire exceeds the calibrated threshold– Faulty Knock sensor (KS) When is

Possible causes – Boost pressure sensor harness is open or shorted– Boost pressure sensor circuit poor electrical connection– Faulty boost pressure sensor– Faulty Turbo/Super Charger– Engine over temperature– Ignition misfire exceeds the calibrated threshold– Faulty Knock sensor (KS) When is

Possible causes – Check Quantity Adjuster– Check Modulator Piston Displacement Sensor Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Check Quantity Adjuster– Check Modulator Piston Displacement Sensor– Check Cold Start Injector– Check Needle Lift Sensor Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Dirty engine oil– Faulty Camshaft Actuator– Camshaft Position Actuator harness is open or shorted– Camshaft Position Actuator circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)– Lack/Loss of power– Engine rough

Possible causes – Dirty engine oil– Faulty camshaft actuator– Low engine oil level– Camshaft actuator harness is open or shorted– Camshaft actuator circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)– Possible Lack/Loss of

Possible causes – Dirty engine oil– Low engine oil level– Camshaft actuator circuit open or shorted– Camshaft actuator circuit poor electrical connection– Faulty camshaft actuator Symptoms – Engine Light ON (or Service Engine Soon Warning Light) VOLKSWAGEN Technical Service Bulletins

Possible causes – Dirty engine oil– Low engine oil level– Camshaft actuator circuit open or shorted– Camshaft actuator circuit poor electrical connection– Faulty camshaft actuator Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Dirty engine oil– Low engine oil level– Camshaft actuator circuit open or shorted– Camshaft actuator circuit poor electrical connection– Faulty camshaft actuator Symptoms – Engine Light ON (or Service Engine Soon Warning Light)– Lack/Loss of power– Engine

Possible causes – Dirty engine oil– Low engine oil level– Camshaft Position Actuator Circuit is open or shorted– Camshaft Position Actuator Circuit poor electrical connection– Faulty Camshaft Actuator Symptoms – Engine Light ON (or Service Engine Soon Warning Light)