- My model of MX-5 is: NC__
- I’m based near: Northampton
- I’m looking for technical help or recommendations on: _P2507 OBD Code
I have a engine light coming on for the above code, I can remove it but it returns. I have replaced the battery, and checked the terminals, does anyone have a repair or any experience. cant get to auto electrician for two weeks
On mine it was the battery.
Have you cleaned (wire wool) the terminals on both battery and battery leads?
It could be a poor connection in the ECM (Electronic Control Module)
Does this help?
DTC P2507 [LF].
This is the battery voltage monitor and any sudden drop . even if only for a short time, will trigger the fault code.
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i tried a new battery and the terminals looked ok but i will do this hope its something this simple.
I have checked the battery terminals everything ok when I came to the ecm it is covered by a plate which has lip covering access to the plug in connector I have never seen these fixings and cannot see a way to get in, the other end is a welded nut.clueless on this one
I can only suggest that you check all the possible connections to the battery / pcm including the earths that you can, to eliminate these. After that I think you need the help and advice of an experienced MX5 electrical Tech.
yes thanks just going through all this now. I found that one of the ecm fuses does not have a connector to hold the fuse at one side although it has a fuse in it ? this is the same on the aircon which never worked but people seem to think it was for optional equipment. do these ever break off ?
They are security shear bolts, they have to be drilled out, same as on a steering lock.
How old is the MX-5?
Assuming an early NC, P2507 is triggered if the 12 volt feed at the PCM terminal 1BA is lost. That should be from a Blue/Red wire going to the PCM (should be top corner of one of the PCM plugs in between 2 Black/Blue wires). This wire is protected via the 15 amp ROOM fuse in the fuse box under the bonnet. Have you checked that fuse (does the interior light/keyless entry work)? If the fuse is OK, next thing to check is for battery voltage at the wire on the PCM.
yes its a 2007 i drilled the bolts out yesterday.and cut off the flap that stops access to the pcm plugs. thinking if it has to go to a auto electrician it will save him some time.I have not checked the room fuse but around the same time my keyless entry stopped so im hoping this is going to fix it.I have a 12 year old renault laguna and so many strange things happen to the electrics which seem to resolve themselves. I will let you know if this is the fix.Many thanks for the advice
fuse good tested with another fuse. but no continuity from the positive battery terminal to the 1ba termimal i suspect a broken wire unless there is a connection somewhere that’s bad looking for a wiring diagram now.
If you look at the link I attached and go to the next page link in red at the bottom of the page it will take you through a number of pages which may help your diagnosis.
yes I have been going through the stages I dont have continuity between the positive battery terminal to the ecu plug,Its getting left now beyond my skill set although I have altered the security cover. so now the auto electrician does not have the same problems I had.
Thank you for your assistance
Glad we were able to help. At least you know where the problem is and hopefully the Electricinans job will be easier (and cheaper!)