Vauxhall fault code P0340: Camshaft position sensor
What is this fault code?
If the ODB-II scanner reports a P0340 fault code in a Vauxhall, then this indicates a problem with the camshaft position sensor. A normal operating camshaft position sensor gives a signal every time the camshaft makes one complete revolution. The ECU (or PCM as Vauxhall calls it) uses this signal for the correct timing of the fuel injection and ignition. The ECU operates the distributor and the injectors with reference to the signal of the camshaft senor. When there is a fault in the supply of this information, the system will not operate correctly anymore. This issue can trigger fault code P0340.
In which car can this fault code occur?
Vauxhall Astra G
Vauxhall Zafira A
Vauxhall Meriva A
Vauxhall Astra A
Basically, several Vauxhall models with a Z16SE, Z16XER/P or Z18XE(R) engine.
Symptoms of the fault code P0340
The (sporadic) missing of the camshaft position signal and the resulting fault code P0340 can cause all sorts of different symptoms. The ECU is in this case not capable to regulate the injection and ignition. This can result in the engine not being able to start, run smoothly, hold back or even cut out completely. It is possible that the engine performance will reduce. The fault can also illuminate the MIL light on the instrument cluster.
Causes of the fault code P0340
The description of the P0340 fault code will point you in to the direction of the problem. A defective camshaft position sensor can cause this fault. Defective wiring or corrosion on the connectors of the sensors can be responsible for this fault as well. Strangely, a not properly connected crankshaft sensor can be responsible for this fault code! And of course a defect in the ECU can cause the data of the camshaft sensor to be corrupted. The Delphi Delco MT35E, Delphi Delco Multec HSFI and Siemens Simtec 71-serie (these are the most commonly used at Vauxhall) are known to cause this fault code due to an internal defect. ACtronics can remanufacture this.
Our advice regarding fault code P0340
Our advice to resolve the P0340 fault code is to verify the camshaft sensor first. Connect the sensor to a scope and verify the signal when the engine is running. Verify if the sensor is a genuine part, often aftermarket sensors produce a different signal that can cause problems.
If the camshaft sensor has been verified to operate correctly, verify the crankshaft sensor. If this sensor is operating normally, then it is likely that the fault is caused in the ECU.