hi did you manage to sort this problem with fault code u0401? I’m getting it

 

did you solve this problem as I’m getting fault codes p0401 and p0183. Thanks in advance, Joe

 

I have the same error codes discovered during investigation or the "thump sound" issue described here (video on Reddit). And I found this official Mazda Service Bulletin describing those error codes, together with REPAIR PROCEDURE. Check whether it's applicable to your VIN first. Basically, recommendation is to replace SAS CONTROL MODULE.
For now I cleared errors, and they not appear again right away. Will wait and see how this thump sound issue progress and when error appear back.

 

And is a good 3 min video on simple fixes to try, starting from checking and charging battery (makes sense, as I had U3003-16 error code also, which is Battery Voltage: Circuit Voltage Below Threshold).

 

I have a Mazda 3 2.2d that has issues with no injector pulse I've spent countless hours checking wiring for volts and continuity
Unlike you I have no codes so it won't run. I purchased a starter set inc pcm, front and rear bcm's, key and module, SSu and several other related modules from a running car
I fitted these...cleared the communication codes and still have the same fault....no injector pulse. The harness tested good as is the fuel pressure and as I have another similiar year Mazda 3 I have been able to swap injectors, map, maf, temp, crank and cam sensors so know they work
I have got readings from a powerscope on the injector leads which can help to determine the difference between the puleses on different injectors
This may save you some time and help to isolate or direct your investigation. Hope this helps.

 

Having problems with no injector pulse (mazda 2.2d sky-activ ...no DTC's stored) which may well be a similiar problem....
What did you do to solve your problem?
Any advice would be greatfully received
ttleader23

 

Welcome to the forum.
the member you quoted has not returned since 2023. It may be better if you started your own thread. Maybe in the future , on most forums look at the thread history such as when it was started and when the last posting was before seeking help?

From a service standpoint very few problems are the same mainly because there are to many different variables that can influence an issue or problem. So starting your own thread makes the Q&A more specific for your vehicle. It also reduces a member reading the complete thread to see what may have already been posted.

Example, your two post lacks ALL the basic and always needed information about your Mazda.

please don’t debate or state reasons why you posted here Iam only trying to suggest a better if not appropriate way to get help .