OBDII ECU

Post by **sproggy29** » Wed Jul 23, 2014 7:35 am

TOP OF THE MORNING TO YOU!

Now then now then, does anybody know if the ECU in my life is learning?

for instance does it remember what you do in terms of take off, revs required, fuel consumption that sort of thing?

Post by **Merlin** » Wed Jul 23, 2014 9:20 am

What do you mean

In what scenario?

Post by **RattyMcClelland** » Wed Jul 23, 2014 10:17 am

Obd2 on 5th gens is a learning ecu but not in the way you described.

Post by **sproggy29** » Wed Jul 23, 2014 11:08 am

I see, then in what way does it learn? Is it as simple as disconnecting the battery to reset it?

Merlin wrote:What do you mean In what scenario?

i meant kind of everyday stuff, i am yet to master the way the car remembers certain things like throttle position. Gear speed (or is that preset?)

Post by **sproggy29** » Wed Jul 23, 2014 11:13 am

If this has been asked i apologise, if there is a link to my question can you point me that way? Thanks

Post by **Merlin** » Wed Jul 23, 2014 11:27 am

The ECU wont "remember" throttle position. It is along the lines of the TPS (throttle position sensor) will tell the ECU what position the throttle plate is in, the ECU will reference that against a set of values in a table to work out how much fuel to dump in and how to set ignition timing (the ECU will also take into consideration a load of other variables such as intake air temp, air pressure etc, O2 readings..).

The 5th gen ECU is fairly pants at adapting to new modifications such as exhausts. OBDII ECU's monitor more sensors than OBDI ECUs. When some sensors fall out of optimal settings (like if a sensor fails) the ECU will use a default value in order to keep the engine running.

Post by **sproggy29** » Wed Jul 23, 2014 12:23 pm

Merlin wrote:The ECU wont "remember" throttle position. It is along the lines of the TPS (throttle position sensor) will tell the ECU what position the throttle plate is in, the ECU will reference that against a set of values in a table to work out how much fuel to dump in and how to set ignition timing (the ECU will also take into consideration a load of other variables such as intake air temp, air pressure, O2 readings etc..).

The 5th gen ECU is fairly pants at adapting to new modifications such as exhausts. OBDII ECU's monitor more sensors than OBDI ECUs. When some sensors fall out of optimal settings (like if a sensor fails) the ECU will use a default value in order to keep the engine running.

okaaayyy, so how do i work out if i.got a fault sensor? Paper clip test?

Post by **Merlin** » Wed Jul 23, 2014 12:27 pm

Can you just come out with the question you have? It will be quicker and easier

Anything immediately serious will give a check engine light on the dash. You can pull these codes by following the tutorial linked below:

http://www.ludegeneration.co.uk/wiki/in ... _and_codes

If you are worried about faulty sensors the Honda service manual shows how to test most, if not all, sensors by measuring their voltage or resistance. http://www.storageserver.co.uk/files/69 ... l.pdf.html

Post by **sproggy29** » Wed Jul 23, 2014 12:48 pm

Bought new generic exhaust, getting some serious rev issues, at first i thought it was a gearbox issue massive revs etc but once temp is up it judders like hell when taking off in first. Also fuel consumption is outrageous since i fitted it check the reducer it came with and made sure the can was tight. Wondering if i should reset the ecu or wether it will learn to enjoy its new exit

Post by **Merlin** » Wed Jul 23, 2014 12:52 pm

It is always best to reset the ECU once you have installed a mod, be it OBDI or OBDII. For a 5th gen disconnect the battery for 30 seconds.

Manual or auto box? Did this juddering happen as soon as the new exhaust was fitted? If fuel consumption is way up and the only thing you have touched is the exhaust I would point the finger at the O2 sensor.