13 replies to this topic

[Mini Oll]

Thanks for all the help so far, however.

I changed the green sensor, I believe it is the air intake sensor, then had a re-reading on the computer. It came up with exactly the same reading as before. The error readings and codes are as follows:

05 - Ambient Air Temperature Sensor
13 - Oil Temperature Sensor Circuit
23 - Oil Temperature Sensor Circuit
25 - Ambient Air Temperature Sensor

The Ambient Air Temperature Sensor is reading -214 degrees C.

The car runs fine though feels lumpy on tick over, and the fuel consumption is still pretty poor.

No one I speak to at Rover or some of the guys who I know in to minis know what this Ambient Air Temperature Sensor is or where it is located.

I have looked through the sections on this forum about SPi problems but couldn't find anything about the Ambient Air Temperature Sensor.

Any help would be much appreciated on any of the aboyve errors.

Cheers

[Sprocket]

Ok I'm not that up on the MPI and by the sound of it the people who should be, your local Rover dealer, are not either, some most of what i am about to say is pure speculation and may in fact be total garbage, but is based on good knowledge and basics of injection systems.


Yes the Inlet air temperature ( the green one in the right side of the inlet manifold) is also know some times as Ambient air temperature. If this was reading -214 then i would suspect that the sensor is open circuit and indeed did need replacing. If however it was replaced and it still reads -214 then there is a fault on the wiring between the ECU and the sensor, worst case it may be the ECU itself. When the sensor was replaced did it read a more normal temperature???

As for the oil temperature sensor, i cannot find any refference on any wiring diagrams to it, yet I can find information on its replacement and I know of its location on the engine. I can only suspect that this also plays a part in the fueling of the engine for this reason, of which is purely speculation. The ecu controls the fueling using several sensors I suspect one of these to be the oil temp along with the ambient and coolant temp. The ECU will bring on the cooling fan when the coolant temperature rises to 95 Deg C and switch off some where around 85 Deg C, in doing this the ECU will also alter fueling slightly for best economy and emissions. If the oil temp were to rise and the coolant temp remain below 95 Deg C the ECU may still bring the cooling fan on to lower the oil temp at the same time over cooling the engine, again causing the ECU to alter the fueling. I suspect that it will increase the amount of fuel delivery.

In my trade as an Air Conditioning technician it is some times the case that when a sensor is reading outside certain limits it will go into fault, it may still be reading, all be it wrong. There can also be two faults from the same sensor meaning almost the same thing (its knackered) one saying its out of range and the other saying that the sensor has failed. Hence why i think you have two different fault codes for the same sensors.

Having said that, I think the MPI also has a limp home mode where the ECU will change to open loop control with fixed fueling and ignition parameters, all this as a result of one or more sensors being faulty.

I would have both sensors replaced , again have a diagnostic check to see that they are reading correctly and then have the ECU reset, I think the member BabyBecks can help you on that one. Remember that the ECU has adapted to the sensors and general tune of the engine over a period of time to try and overcome running problems. When there is a fault which is fixed, there is an imediate change to the tune of the engine that the ECU will take time to adapt to so the benifit of these new parts may not be evident and may actualy cause the engine to run worse for a while. This is the reason the ECU needs to be reset.

[Mini Oll]

Thanks very much. Excellent help, will try cleaning the wires and checking everything is ok.

[BabyBek]

Hope you got it sorted..

With regards to resetting the ECU... you do it as follows..

Turn ignition to 2nd click
Turn immobiliser off
Pump accelerator pedal, slowly to the floor a total of 10 times
Turn ignition off
Then back on
Start

You ought to reset the ECU every time a sensor is changed.

[Mini Oll]

Still not sorted but will try this tonight. Cheers.

[Wiggy]

Hope you got it sorted..

With regards to resetting the ECU... you do it as follows..

Turn ignition to 2nd click
Turn immobiliser off
Pump accelerator pedal, slowly to the floor a total of 10 times
Turn ignition off
Then back on
Start

You ought to reset the ECU every time a sensor is changed.

As far as I'm aware, that resets the Throttle Position Sensor.

As for resetting the ECU totally, I think you have to disconnect the battery for a reasonable amount of time.

Of course, someone correct me if I'm wrong.

[icklemini]

Hope you got it sorted..

With regards to resetting the ECU... you do it as follows..

Turn ignition to 2nd click
Turn immobiliser off
Pump accelerator pedal, slowly to the floor a total of 10 times
Turn ignition off
Then back on
Start

You ought to reset the ECU every time a sensor is changed.

As far as I'm aware, that resets the Throttle Position Sensor.

As for resetting the ECU totally, I think you have to disconnect the battery for a reasonable amount of time.

Of course, someone correct me if I'm wrong.

Yeah disconnecting the battery (24 hours or so) will reset the ecu back to factory so it can relearn.

Pumping of the pedal with the ignition on II then on the nth pump start the car = reset the closed throttle angle of the throttle body.

Reseting the throttle position sensor is done by wedging the pedal up, and manually operating the throttle all the way 5 times under the bonnet when the ignition (but not engine) is on.

TTFN,
Dave

[Sprocket]

Here we go again , no real true answer to resetting the ecu without a diagnostic . Rover Tech CD states the Testbook (Rover Diagnostic) as the only method to reset, mentions nothing else . Its back to one saying one thing and another saying another and no one saying for sure what gets it done.

So here it is

To truely reset the ECU you need a diagnostic terminal.

There you go, that's settled it.

There may well be another way but can you be sure???

No offence intended to those suggestions above, btu no one has yet substantiated it yet :'(

I shall go trawl through pages of Rover tech info

[icklemini]

Here we go again , no real true answer to resetting the ecu without a diagnostic . Rover Tech CD states the Testbook (Rover Diagnostic) as the only method to reset, mentions nothing else . Its back to one saying one thing and another saying another and no one saying for sure what gets it done.

So here it is

To truely reset the ECU you need a diagnostic terminal.

There you go, that's settled it.

There may well be another way but can you be sure???

No offence intended to those suggestions above, btu no one has yet substantiated it yet :'(

I shall go trawl through pages of Rover tech info

want to borrow my Diagnostic Kit ?


<was going to write a long spiel about it all - but ICBA!>

TTFN,
Dave

[BabyBek]

All I know is that what Tarks told me!! I'm blonde and female so am not about to get into a technical 'thing'..... but as he did it after replacing my engine I suppose the battery would have been diconected for a while in my case.... so....hmmm... sorry if I've mislead anyone....


Moral of the story... Don't trust a female!!

[THedooBZ]

to truly reset the ecu this would involve clearing the CMOS or similar memory base in the ecu, but dont go ripping it to peices to do this, i would say the only way you can do it is by rover diagnostic but nobody really knows.

[Sprocket]

Here we go again , no real true answer to resetting the ecu without a diagnostic . Rover Tech CD states the Testbook (Rover Diagnostic) as the only method to reset, mentions nothing else . Its back to one saying one thing and another saying another and no one saying for sure what gets it done.

So here it is

To truely reset the ECU you need a diagnostic terminal.

There you go, that's settled it.

There may well be another way but can you be sure???

No offence intended to those suggestions above, btu no one has yet substantiated it yet :'(

I shall go trawl through pages of Rover tech info

want to borrow my Diagnostic Kit ?


<was going to write a long spiel about it all - but ICBA!>

TTFN,
Dave

What was the point to this

[icklemini]

to quote:
"Its back to one saying one thing and another saying another and no one saying for sure what gets it done."

[Matt2020]

Have you sold this car? as I think I have bought it - with its problem??  (R620 RRA) MPI Rover Mini Cooper.

If have any ideas on this, please let me know.

 

cheers