|
|
Post by refandy on Apr 30, 2021 19:47:37 GMT
Update on this one, I decided not to trust the dealer and had the car move home. It still starts, idles at 2500rpm ish and has no throttle response at all. So I decided to take a look myself, I had assumed the ecu was inside the car but eventually found it in engine bay under the air filter. No obvious signs of any water damage or corrosion to it or the wiring and multi plugs. Checked inside the car no signs of moisture anywhere either. I borrowed a code reader and cleared the only error code which was P2138 accelerator pedal position sensor 1/2 implausible voltage ratio after refitting the ecu, she now starts runs and revs fine but sometimes loses throttle response and code resets after turning engine off and restarting. Clearing code again 50% of time gets it revving again. I’m suspecting the ecu may have a problem. I’m trying to think of a way to confirm this? Any ideas pls? Tia
|
|
|
|
Post by atlex on May 1, 2021 8:42:01 GMT
|
|
|
|
Post by refandy on May 1, 2021 12:08:46 GMT
Thanks Atlex, that’s really useful info. I’m assuming both PPS 1/2 are built into throttle pedal unit?
|
|
|
|
Post by refandy on May 1, 2021 12:10:28 GMT
Also PCM is a different term for engine ECU yes? Thanks
|
|
|
|
Post by atlex on May 1, 2021 13:34:38 GMT
I genuinely don't understand what some of the acronyms are. PCM - power control module ? ecu.
I suspect this being drive by wire they're comparing the position of the pedal vs the position throttle body - and one of the sensors is giving a 'wrong' reading.
The error reads like this condition:
i.e. at 50% pedal the throttle is at 30%, when it should be 50%. the ECU expects the same voltage from the sensors for the same relative position.
in this case if the car is idling high it means that throttle is more open than the foot pedal is?
if that's the case you may want to clean the throttlebody (it may be stuck! clean with car intake cleaner aka carb cleaner ) and see what happens, or clean the input power supply connector that activates it (electrical connector cleaner)
|
|
|
|
Post by refandy on May 1, 2021 15:40:31 GMT
First thing I did when I got it home was to clean throttle body, It was fairly clean already and didn’t improve things. I have noticed that when clearing the error code with ignition on the throttle body can be heard chattering/moving and then it revs normally when started. Thanks for your help
|
|
|
|
Post by refandy on May 1, 2021 15:42:28 GMT
One other thing, with engine running charging voltage is about 13/13.2 volts is that normal? I was expecting more like 14.4v
|
|
|
|
Post by atlex on May 1, 2021 19:10:22 GMT
yeah I'd expect more voltage. could be a factor. get that battery charged up. try another car's battery.
also, sounds like the electronic throttlebody is going through a calibration check.
could be the sensor (either the throttlebody or the pedal one)
could be the motor that drives the throttlebody based on the pedal sensor input. (but I'm guessing not since you can hear it moving..)
|
|
|
|
Post by atlex on May 2, 2021 19:23:18 GMT
another simple thing to check but that does require someone to help you..
get the key to the point just before it starts turning the engine - power but not ignition.
take the hose before the throttle body off so you can see the throttle body
get someone to depress he accelerator and visualy verify the throttlebody actually moves in the same gradient.
|
|
|
|
Post by refandy on May 3, 2021 9:13:27 GMT
Thanks, will do
|
|
|
|
Post by wannabe on May 4, 2021 14:17:03 GMT
If you haven't already tried a new / known-good battery, I think swapping/testing that is the easiest/quickest first attempt - low voltage does weird things so it can't hurt to try to borrow another battery and see if it makes a difference.
|
|
|
|
Post by refandy on May 19, 2021 18:36:10 GMT
Thanks for all the advice, this is a great community of people wanting to help out.
The car is fixed! Eventually I noticed the voltage Reading showing on the scanners live data for “Pedal position sensor 2” was fluctuating between 1.5v and 3.5v without the pedal being moved. Unplugging the throttle pedal caused all voltages to show 0v
I fitted a second hand throttle pedal and problem solved.
So from a dealer quote of £3500 for a new wiring harness and ecu to fixed for £17:99 by us!
Can only really think of 3 reasons the dealer got this wrong
1, they were deliberately trying to rip me off
2, they don’t have a clue what they are doing
3, they were just guessing and trying to cover all possibilities.
Ironically if I had authorised the £3500 repairs it still wouldn’t have fixed the car.
Thanks Again
|
|
|
|
Post by atlex on May 19, 2021 18:57:20 GMT
Glad this is sorted the way it should have been. Stealerships  |
|
|
|
Post by dadbif on May 19, 2021 21:10:27 GMT
All three....
Can only really think of 3 reasons the dealer got this wrong
1, they were deliberately trying to rip me off
2, they don’t have a clue what they are doing
3, they were just guessing and trying to cover all possibilities.
Glad you fixed it, great feeling isn’t it!
|
|
|
|
Post by wannabe on May 20, 2021 9:23:50 GMT
Good news!
I'm sure getting into the footwell was a PITA, anything under the dash seems to involve being a contortionist, lol.
TBH I'd be tempted to write to the dealer and Mazda UK - a £4k 'fix' that was based on, er, no evidence, and which still wouldn't have fixed the problem, cannot be good for business and customer perception in the long term, unless their business model is that of a 1980s Arthur Daley character. If Head Office see fit to inspect your vehicle and find no evidence of the issues claimed, I would hope that words would be had and other customers would not be ripped off.
|
|
