Vauxhall Corsa 69 plate - engine light / losing power

Arsenal2019

Hello

I have a 69 plate Vauxhall Corsa and recently my engine light has appeared and says “engine fault repair needed” when the car starts and the light remains on. 

When driving, the car sometimes  does not accelerate and gain speed, even when my foot is pressed on the accelerator. It stays at this speed for a few seconds before it accelerates and gains speed as it should do. Other than that it seems to drive fine?

Does anyone who is mechanically minded or have experience of this know what the issue is?

TIA

paul_c123

It needs to be diagnosed.

Arsenal2019

paul_c123 said:

It needs to be diagnosed.

It’s booked on Tuesday. Just trying to mentally prepare myself 

paul_c123

I'm happy to wait until after Tuesday to find out what it is.

daveyjp

If its a petrol it could be yet another failing coil pack - a common issue - but a diagnosis will soon identify that as a problem.

Arsenal2019

daveyjp said:

If it’s a petrol it could be yet another failing coil pack - a common issue - but a diagnosis will soon identify that as a problem.

It is indeed petrol 

Goudy

These do suffer from a throttle position sensor fault and you get these exact problems.

Throttles are no longer controlled by cables, there is a sensor each end. So one (or two) on the pedal and one on the throttle body.
The signal from the pedal operates the motor on the throttle body to open and close the throttle "flap" and the sensor on the throttle body confirms the position.

When either position sensors fail or are faulty the cars powertrain ECU can't match the two signals up, hence the engine management light but it also can't control the throttle body properly.
Either the input signal or the conformation signal is lost or intermittent so you get either no power or a hesitant, jerky throttle response.

They are potentiometer type sensors, so give a gradual reading based on their position and quite often there are two sensors at the pedal and an average signal is used.

These models of Corsa are prone to the pedal sensor failing.
It's well noted but dealers have sometimes been known to throw all sorts of parts at this problem before actually using their diagnostic tools properly and checking the sensors output over the entire range/position. 

I believe the diagnostic trouble code for this is P2138.

If it is, it's not an expensive fix, it's a new pedal assembly but you will no doubt be charged a set diagnostic fee that might be high if you take it to a VX dealer.

Arsenal2019

Goudy said:

These do suffer from a throttle position sensor fault and you get these exact problems.

Throttles are no longer controlled by cables, there is a sensor each end. So one (or two) on the pedal and one on the throttle body.
The signal from the pedal operates the motor on the throttle body to open and close the throttle "flap" and the sensor on the throttle body confirms the position.

When either position sensors fail or are faulty the cars powertrain ECU can't match the two signals up, hence the engine management light but it also can't control the throttle body properly.
Either the input signal or the conformation signal is lost or intermittent so you get either no power or a hesitant, jerky throttle response.

They are potentiometer type sensors, so give a gradual reading based on their position and quite often there are two sensors at the pedal and an average signal is used.

These models of Corsa are prone to the pedal sensor failing.
It's well noted but dealers have sometimes been known to throw all sorts of parts at this problem before actually using their diagnostic tools properly and checking the sensors output over the entire range/position. 

I believe the diagnostic trouble code for this is P2138.

If it is, it's not an expensive fix, it's a new pedal assembly but you will no doubt be charged a set diagnostic fee that might be high if you take it to a VX dealer.

thank you for your response ! Hopefully it is the cheaper option -_-