DTC P0010, P0020 Variable Valve Timing (VVT) Explanation, Inspection & Repair

Mercedes Benz Workshop Information System
the original factory dealer repair software system

BMW Technical Information System
bmw dealer repair software with electronic parts catalog

These codes refer to the VVT (variable valve timing) or VCT (variable camshaft timing) system on the vehicle. P0010 refers to the intake camshaft on a single cylinder head engine or bank 1 of a multiple cylinder head engine. P0020 refers to the intake camshaft on bank 2 cylinder head of a multiple cylinder head engine.

DTC P0010 and P0020 indicate possible electrical problems. If you have DTC P0011, P0021, P0012 and P0022 please see the appropriate article as these should be considered more of mechanical failure codes

The symptoms of course are the Check Engine Light illuminated (Malfunction Indicator Lamp), low power, possibly rough running , hard starting, poor idling or even stalling. The symptoms are of very little use in the diagnosis except for confirmation.

The system is installed into the vehicle to increase the power from smaller displacement engines. When the camshaft timing is advanced, it allows more air and fuel into the combustion chamber, which increases the power without sacrificing idle quality. Thus the owner gets the best of both worlds, great performance, good fuel economy and an acceptable idle.

The system is rather simplistic in design; it is a solenoid, which the PCM applies the ground circuit at the correct time and in the correct amount, which controls engine oil flow to the camshaft timing plate.

Start your diagnostics with a proper OBD2 Baseline Diagnostic Procedure, to ascertain what condition the vehicle is in. This is followed by a look into the maintenance records. Items of importance would be;

• Has the engine been replaced?

• Has the cylinder head(s) or head gaskets been serviced recently?

• Has the engine supports been replaced recently or are they broken

If this is a used vehicle and no records have been provided, visually inspect to see what has been done. This can usually be told by wrench marks on the bolts, gasket sealers, etc. If the engine has been replaced it is very possible that some PCM wiring may have been damaged during the service. We have observed vehicle wiring damage from an engine replacement not show up until a year later.

The electrical circuitry is very simple in design, typically a 12Vdc power supply to the solenoid, a ground wire (PCM grounds this to apply), and the feedback wire to the PCM to verify function.

To perform the tests requires either a Digital Multi Meter (DMM) or a Digital Storage Oscilloscope (DSO), a scan tool like the 2X80S or the OEM scan tool, some jumper wires, and lastly the wiring diagram for the system.

The first test is to check for 12Vdc to the OCV with the wiring harness removed and the key on engine off. You should check the OCV solenoid for continuity across the correct terminals while the wiring is removed.

Reconnect the wiring harness, connect the scan tool, and start the engine. If you are using the OEM scan tool, you could command the OCV to apply and monitor the feedback signal on the correct wire with the DMM or DSO. If you are using the 2X80S, watch the PIDs you use to verify timing control, mixture and rpm. Establish a base reading set, then manually apply the OCV ground and watch for the appropriate changes.

Keep in mind that solenoids can and do fail electrically, but you should check for possible causes of failure like over voltage supply. Simply changing the OCV may solve the problem, but unless a reason for its failure is found and corrected. You may have to replace it again…under warranty!



Actia Pass Thru XS J2534 Reprogrammer 2X80S OBD2 Scan Tool $49.95 GM OBD1 Software & Cable kit 2X80S Bluetooth Scan Tool $89.95 Centech Digital MultiMeter $59.95 VW Audi Seat Skoda ELSA Win Software
Actia Pass Thru XS J2534 Reprogrammer
2X80S OBD2 Scan Tool $49.95
GM OBD1 Software & Cable kit
2X80S Bluetooth Scan Tool $89.95
Centech Digital MultiMeter $59.95
VW Audi Seat Skoda ELSA Win Software
view cart button  

         Fix It Right The First Time!

Fortunately, everything you need everything you need to fix it right the first time is right here!

To access the sensor and data from your Engine Controller (PCM) you will need:

Professional Quality Scan Tool such as our 2X80S Scan Tool series.

Professional Quality Automotive Diagnostic Software such as OBD2 Spy, OBD 2007, or Scan Master.

If you understand how the systems were designed to work and how to test them, great! Otherwise you will need factory product service training manuals that will teach you and guide you through the diagnostic phase.

You might also need the manufacturer factory service manuals and data systems that provide specifications and details relative to your specific model.

Or aftermarket data systems such as All Data, Mitchell On Demand, Auto Data, Bosch, and others.

Everything is available here for you as a single source for all your needs. The aftermarket data systems are available in our members only area by direct shipment from the distributor at great pricing.

     New Products