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Debating this with me is counter productive to helping you.
Ok so just saying this is not how an ECU works.
There is not a OBDII or CANbus control system I can't find the cause of the target area in an hour or less. You have a communication concern with your ECU. What you have said from the first post you should have multiple DTCs and your monitors will show in fault. The target area is the ECU.
ASE
Good luck with your Mazda
so what DTC's should be populated with a no start condition?
so what DTC's should be populated with a no start condition?
GREAT QUESTION;;; It can be technically many or any single DTC . Even the DTC that are shown that are generic cause by anomalous condition can help identify the actual issue when other information is obtained in the ECU. Part of getting all the information from the ECU is problem solving first by getting all the DTC and then to determine which were not generated by the actual cause but by not resolving the original.
If any ECU OBDII or CANbus controlled engine does not start you will get a DTC(S). (OBDII from 2002 to preset) And if not then the first step is to determine why!
You are seeking an easy answer and there is not one until you first resolve why the ECU is not reporting a no start!
Last edited by Callisto; Nov 13, 2024 at 09:46 AM.
i think that what you said may be throwing me down a dead end. i took a known good 2018 cx-5 2.5 and i pulled the coils while leaving them plugged in and tried to start. it obviously didnt and i got no codes. i replaced the plugs rerouted fuel line to an outside source and tried to start and got no codes populate. so am i missing something? is there a different area where these codes are supposed to populate or....?
i think that what you said may be throwing me down a dead end. i took a known good 2018 cx-5 2.5 and i pulled the coils while leaving them plugged in and tried to start. it obviously didnt and i got no codes. i replaced the plugs rerouted fuel line to an outside source and tried to start and got no codes populate. so am i missing something? is there a different area where these codes are supposed to populate or....?
No I am not throwing you down a dead end...
If there are no DTC then you have either a ECU failed completely or a harness/connection problem that powers the ECU or the direct connector itself.
Or your ignition switch electrical connection are damaged or for some reason shorted out.
Time to dig out the Digital volt/ohm meter and start doing some electrical continuity testing.
You test should have gotten at least a Cylinder DTCs when you disconnected them and attempted to start.
If you were in our shop I would have seen a no communication with the ECU pulled out and ran a pass-through. If it failed to take the pass-through then it is a failed ECU. But I know you don't have one so your either look for a connection issue or pull your ECU and take it to a shop that can do a Pass-through. Or roll the dice and buy a re-built ECU with a Warraty.
I don't "GUESS" at a answer to a problem and post the best service advise based on the usually limited and very DIY information. So while you think I am " throwing YOU down a dead end" I am not and you still don't get how an ECU reports a no start?
