I have a very odd situation. Let me start by saying I thought I was in safety boost as I was only boosting to 7psi. However ECU diagnostics ran all clear (55).

 

As everyone knows in the Safety Boost scenario the ECU changes the fuelling maps and limits the boost levels.

 

The Wastegate Solenoids do the boost limiting. Normally the ECU earths the circuit (through pin 25) in order to turn them on (normal boost), and 'floats' the earth in safety-boost to turn them off.

 

They are "ON" (normal boost) when:

- Engine is running

- TPS voltage is above 0.1v

- No Detonation

- Coolant is above 55 degrees

 

Now I have run Datascan and everything operates as it should. Datascan says the Wastegate Solenoids are going "on" at the right times. They are "off" at idle, just give the accelerator a kick and they go "on". Which is a HUGE relief because I was thinking it was time to fit a new Det sensor.

However!

 

Datascan is lying. The ECU never actually earths the pin when Datascan says it is, I know because I have checked pin 25. And i know it has the ability to earth it because at engine-off key-first-click it is earthed. Second-key-click it is floated, idling it is floated, running it is floated, it never earths it, which means my boost is ALWAYS limited. :(

 

Any ideas?

anyone?

Only thing I can think,is if the Datascan says it's earthing but isn't,it's the ECU telling lies not Datascan??

Could try another ecu to tell me I'm a Pleb! :D

Are you sure it's really earthed at first click and not just reading earth through the coil as there is no +ve on the other side and that is then earthing it through something sharing the +ve line?

Could just be a blown output on the ECU?

Are you sure it's really earthed at first click and not just reading earth through the coil as there is no +ve on the other side and that is then earthing it through something sharing the +ve line?

Now theres a thought, I will eliminate this by unplugging in the engine bay, and test again.

 

Could just be a blown output on the ECU?

Will this be obvious if I open it and check?

 

Would a ROM data file help in any way? When I asked Datascan to download the ROM nothing happened, how long does that usually take? All I managed was to take screenshots of the Fuel and Timing Maps, which doesnt really help in this case!

Only thing I can think,is if the Datascan says it's earthing but isn't,it's the ECU telling lies not Datascan??

Could try another ecu to tell me I'm a Pleb! :D

 

To be honest, that was my first thought too. Except I just sold my spare TT ECU . :slap: Anyone loan one?

 

Are you sure it's really earthed at first click and not just reading earth through the coil as there is no +ve on the other side and that is then earthing it through something sharing the +ve line?

 

John, that is spot on unfortunately. Disconnected the solenoids and bingo, no earth on 1st click. :(:(:(