NEED help to diagnose the issue

Do you think the ECU is bad?

Thank you Danh, may be but not sure and I need evidence to change any parts from now on. Freddy

Does the Airbag Control Module have good powers and grounds At All Times (confirmed with lengthy oscilloscope capture)?

Hi Dmitriy, I didn't confirm the powers & grounds with oscilloscope but did confirm it has good powers & grounds with voltage drop at the time of event. Freddt

Sounds like you have a common problem causing all of the issues. Some things just won't pick up on a scan tool or set a code. Like low fuel pressure or a failed pump. I'm thinking you have a power/ground issue or a bad battery not up to full charge. Maybe a bad cell dragging it down. Could just be a bad connection at the battery or fuse box. These modern cars computers are very sensitive to…

Is it possible to monitor all relative dat, load , tps, all relevant commands to control idle and throttle, find out first what is being commanded to shut off then read service data on fault setting criteria and action taken.

Thank you for your input Matthew, I did have a look all data at the time of event like you said but can't see any abnormal data. The sanp on tool(Modis edge) doen't give much information like factory scan tool and wish to have flight record feature in it. Freddy

Hi Jesse, thank you for your input. will keep in mind that but it's not fuel related issue as it starting straight way after stalling. The vehicle has a denso fuel system which has no low pressure fuel pump in the tank but using a suction pump in the high pressure fuel pump. If this vehicle has fuel starving issue, it won't start straight way after stalling and further more no issue at…

I'm not saying it is fuel related. I'm saying that there is a common issue somewhere in the system linking everything together. One bad sensor or module/computer can cause other issues not related. Unplugging one at a time, if possible, is a good test. I was thinking about you saying that there was no throttle after sitting running for 5 minutes while in the store. I'm wondering if a weak…

Thank you Jesse for your input, Yes, I agreed with you. Something which is not related to engine is contributing the issue to cause engine performance issue and I think the ABS module is possible the cause of the problem but can't drive with ABS module disconnected as it will lose power steering assisst. The vehicle starts straight way with one go/no delay/no weak cranking after stalling, so I…

Hi Jesse, thank you for your input. I will keep in mind that but it's not fuel related issue as it starting straight way after stalling. The vehicle has a denso fuel system which has no low pressure fuel pump in the tank but using a suction pump in the high pressure fuel pump. If this vehicle has fuel starving issue, it won't start straight way after stalling and further more no issue at…

Which module (s) are storing the codes?

Hi Kyle, Thank you for your reply. Please see the table in the post. Freddy

Hello Freddy, Judging from the multiple U codes and problem will not occur with the airbag module disconnected, I suspect the com lines going to the airbag module are pinched or damaged somehow. Check for any recent repair history or aftermarket devices added to the vehicle. The system strategy of many manufacturers is to disable engine and transmission components during a collision event…

Hi Glenn, Thank you for your reply. The yaw rate sensor related issue is not occuring any more after replacing airbag control module and the stalling issue is not occuiring with auto idle stop function activated. The front sensing camera or sensos not damaged and couldn't find any smash repair evidence. The issue is not occuring any more after driving 400kms and decided to realease the…

Hi Freddy, Anything new with the Mazda? did you solve the problem yet?

Hi Danh, May be becsue the issue is not occuring any more after changing the air bag control module and ABS module. It's hard call and don't like fix like this. Regards, Freddy

Hi Freddy, I understand how you feel. I think it might help if you look up a subject called Air Bag Systems and Vehicle Kinematics. In modern vehicle, “systems” are not stand-alone operations. The modern safety systems like air bags, ABS, steering along with the engine and transmission functions all communicate on CAN bus systems. If one has an issue the others are alerted and often react to…

Hi Freddy, I forgot to mention to check the K line data also. This is where much of the Air bag system communicates. Here is a brief CAN sheet with DLC pin identifications: OBD_II_Specifications_and_Connections​.​pdf (esatinc​.​ca)