Vauxhall Fault code P0170: Fuel Trim Malfunction (Bank 1)
What does this fault code mean?
If you read the OBD-II fault code P0170 on one of the different Vauxhall models, then the fuel injection values are outside of the manufacturer’s specifications.
What models suffer from this code?
Vahuxhall Astra G
Vauxhall Meriva A
Vauxhall Vectra B&C
Vauxhall Zafira A
In short, all models equipped with the 1.8 (Z18XE) engine.
Symptoms for fault code P0170 (Vauxhall)
A deviation in the fuel-air ratio causes the engine not to run at optimal performance. It can cause a loss in engine power. The engine can have problems starting in certain cases and sometimes idle rpm will be irregular. If the fault is not repaired it could cause damage to the catalytic converter. Therefore, in many cases the engine management light on the instrument panel will illuminate when the P0170 fault is triggered.
Causes of the fault code P0170
The fault code P0170 can be caused by parts like the fuel filter, fuel pressure regulator or the air mass meter. The adaptive values in the ECU are adjusted so far that they will be outside of the normal parameters. Another cause can be a defective ECU. Especially the Simtec-71 Series combined with the 1.8 litre (Z18XE) engine that is used by Vauxhall is known for creating an internal fault. One or more injectors cannot be continuously controlled anymore, what can lead to strange faults.
Our advice for a P0170 fault
First reset the adaptive values that the ECU has learned. Then verify parts like the fuel filter, fuel pressure regulator and air mass meter and make a test drive. If there are no defects and the P0170 fault returns then please contact us. The fault might be located in the ECU.