Hi All,

I have a Mazda2 that has suddenly refused to start. When trying to start it via the button, a loud buzzing noise (relay?) occurs in the fuse box, which just continues until the start button is pressed again.

The very odd thing is that when I plug in an OBD scanner, hit the start button again, the car miraculously starts. Pulling out the scanner causes a stall and the car refuses to start again.

The issue is clearly electrical, but before I take it to the garage, does anyone have any ideas what it might be?

Thanks,

Matty

 

Weird glitches like that usually caused by lose grounds. Needs proper inspection. Seems like some module finds ground through obd adapter. Wild guess: check PCM ground (G01), near the battery.

 

I have to agree partially! The common electrical problem with many models Mazda is the inadequate grounds and also poor continuity of the ground cable at the battery and at the frame or chassis where it is connected. the "HIGHEST" amp draw from the battery is from the start, so it is vital that the battery, the batter terminal as well their cable connections at the frame ground and at the start are in good condition and clean.

I would stop using the Scanning as a ground because you can damage the ECU in some cases containing this forum of starting and especially when you unplug the scanner as you described the event.

I will add unless you are a bit more experienced, I would not use "guessing information from any member especially when it concerns anything to do with your ECU, PCM, TCM. I would say we get at least one vehicle a month that a DIY fried their ECU by attempting to correct an electrical issue.

 

Welcome to the forum

 

Hi,

Thanks for your responses. The issue has been resolved (for now) by erasing an error code that appeared. (The code was P2610.)

I would like to get a basic code reader to spot any error codes that appear in future. Is there a recommended unit (cheap-ish) that can both read and erase codes on Mazdas?

Thanks,

Matty

 

I use a CEN-TECH # 60694 that I keep in my vehicle that I drive. It is a simple and inexpensive scanner that works very well. Not to expensive. In the shop I have a Snap-On Soleus with additional several hundred dollars in soft wear and other program to diagnose just about anything having to do with ODDI, OBDII and CAN-Bus. But it is very expensive. $$$$

I do not really recommend Blue Tooth scanners, but some seem to like them. Maybe that is a personal preference but often customers will tell me what is wrong with their vehicle when they bring it in the shop using them and more times than not they were mistaken.