My Step-Daughter 2016 CX-5 will occasionally not start. jumped it early in the week thinking it was a Bad Battery. New Battery installed but still occasionally not starting.
ran a code reader on it and here they are:
U3003-16 battery Voltage Circuit voltage below threshold.
U0462-86 Invalid data receive from restraints control module - signal invalid
C0051-67 Steering wheel position sensor – signal incorrect after event
C0089-64 (TCS) disable switch – signal plausibility failure
U0401-00 invalid data received from (ECM)/(PCM)
C1031-54 deflation detection system – missing calibration
C0040-64 brake pedal switch A – signal possibility Electric Parking Brake Warning light

The TCS/DSC Indicator Light and TPMS Warning Light are on constantly. While driving it the other day The Electric Parking Brake Warning light, check Engine light and Master Warning Light all came on.
What area do ya'll think I should start.
Appreciate any help...

UPDATE: Reset all codes, drove it a couple of times and the only code that came back was for the Brake Pedal Switch. quickly replaced and so far no more intermittent starts.
For the TPMS and TCS Warning Lights: While rotating the tires, I pulled each wheel speed sensor and cleaned. magically both warnings are Now gone.

 

Test the battery voltage while the engine is running, and during vehicle start up. There might be quite a bit more to do after that, but that's a good place to begin the diagnosis.

 

Copy, thanks, while getting the codes, I did the Battery test and Alternator run up. both said good on the meter. I'm thinking of starting with the Brake Pedal switch, but will drive it again tomorrow to see what codes have came back after today's reset.

 

What was the running voltage reading? Those codes are not being caused by a bad brake switch. IMO there is some type of electrical/charging issue, and I'd be doing things such as checking grounds and other voltage drop testing if it were mine.

 

Thank You, the voltage while running showed 13.5. I think originally the battery was weak and due to replace. I zeroed the codes and test drove it. the only code that popped after was for the Brake Switch, which i quickly replaced and so far has fixed the intermittent not stating.

 

Multiple non-related fault warnings are most often caused by a bad battery. Measuring the resting or running voltage is a waste of time, what matters is the voltage under load. A battery with “good” resting voltage can fail under load. Take the CX to an Autozone or similar auto store and have them load test the battery. That will tell you if the battery (new or old) is bad.

Another possibility is a loose connection on the battery. Check for looseness and tighten as required.

 

U3003-16 battery Voltage Circuit voltage below threshold: This code could be related to the intermittent starting issue, although you mentioned that you have already replaced the battery. It may be worth checking the battery connections and cables to make sure everything is secure and in good condition.
​​​​​​https://dtcvehicles.com/u3003-battery-voltage/

 

So I get CEL on dashboard and get OBDII codes P013A,U0401:00, u3003:16. Vehicle showing no signs or symptoms previously except door actuator clicking constantly when cold outside and occasionally interior lights misbehave. I hear U codes are generally not a big concern but I’m wondering if I should be concerned with those symptoms? Also, could it just be that the 02 sensor issue is triggering these codes because I got all three all of a sudden. Is it possible these codes are only coming up with CEL because I need to change 02 sensor? I’m terrified to go to dealer because my previous vehicle from them went in for 02 sensor and never returned with them stating pcm went bad and even after changing it they couldn’t figure out issue. (That’s a whole other story but you can see my mistrust with their abilities and their trash vehicles since the previous gave issues from day one of having it)

 

Please provide the part number you used. Also is this considered the Pedal Travel Sensor? I understand that it may be a different part number on different vehicles.
Thank you.

 

Or is this the switch?
OEM NEW 2004-2019 Mazda 3 6 CX3 CX5 CX9 Brake Pedal Stop Lamp Switch BN7N66490A
Part Number: BN7N66490A