I have a 2014 Mazda CX-5 with 91K miles on it. It developed a problem recently where about 8-9 dashboard warning lights are on. I replaced the battery and that didn't help.

I took it to a local auto service dealer (not Mazda authorized) and they said that the ABS module has no power and communicating. As a result the other things are failing too. The speedometer remains stuck at 0. The car doesn't turn off easily. I need to told the on-off button for 3-4 seconds and then accessories remain on. I have to again keep the button held for another 3-4 seconds to fully turn off the car.

Any ideas if I can debug this further myself rather than bringing this to Mazda service center? Could it be something simpler? Anything that I can do to confirm before paying $400 to Mazda for just diagnosis (their quote over the phone)?

 

For any weird electrical problem like this one, one easy thing to try is keeping the battery disconnected overnight. But before disconnecting the battery, scan all of the control units for fault codes using an advanced reader which is capable of reading the systems that basic readers cannot (regardless if the CEL is on or not). Then, as soon as possible after reconnecting the battery, scan again to find out what shows up at that point.

 

Take it to Mazda.

 

Thanks. I did that. Reconnected the battery this morning and no improvement so I guess I will have to take it to Mazda and hope they figure it out without too many false starts and expensive repairs.

 

Ouch.. I could be jumping to conclusions but possibly something taking down one of the networks in the vehicle (often a module but sometimes corrosion or other wiring faults). I'm more familiar with the architecture of the various GM networks but it often involves accessing and testing at each individual module (often in not very accessible places) or unplugging them one by one until the network comes back up to identify which branch has the fault and then isolating the cause. $400 initial estimate is probably fair as at the worst it can take days to isolate if it's a thorny problem. (But it feels so good when you methodically work to the root of the problem and one part or wiring repair fixes it! - The hopefully rare times it doesn't well... it sucks but hopefully gives a clue to why and what to check next or led you astray in the diag.)

I would respectfully ask the dealer to put one of their best computer guys on it even if it meant a delay - you don't want a parts changer for this; God knows how many of their mistakes wound up in my service bay over the last 36 years before I retired. That said I hope for both you and the tech involved it's something simple and stupid like a penny stuck in the lighter socket blowing a fuse or similar. (Not likely to be that specific cause but on GM it disabled communication at the diag port and I probably could have bought a soda with all the ones I removed over the years for small complaints or to re-establish communications for OBD inspection or other diag.) Do keep us advised on progress please and feel free to see if what they are saying sounds right.