# How NOT to fry the car ECU?



## BruneiCruze (Aug 22, 2012)

Well I hope the title gets some attention 

I got my car 6 month ago or so. It came from the dealer with an aero package (skirting etc) plus DRL. When I first had the car and drove around 20-30KMH (which is very slow) the car transmission was not very smooth. I was not sure if its because of the break in or if it is a car defect so I did send it to the dealer to check. They told me that it has to do with the DRL which the sub con did not install properly because he wired it to the battery and fuse box next to the engine. I met the sub con and he pulled the cable into the fuse box at the passenger side inside the car. I am not sure if the problem was solved or if I got used to it,.... Couple of month ago, my engine lights went on and staid on whenever I did drive fast 120KMH and above. Again I send the car back to the dealer, after a few test they concluded that the ECU has been damaged. Finally the ECU arrived and my dealer is charging the sub con for it because they did install the DRL wrongly.My dealer told me that any aftermarket electronics can and will damaged the ECU and other electronics sooner or later (maybe in one or two years), even parking sensors, reverse cameras, aftermerket radios, electronic mirrors etc. And on top of that the warranty will be voided.

So enough of the bla bla and to the question: Is it true that aftermarket electronics will eventually damage the car electronics? And how save is the below for my ECU?

+ I have a revers parking aid and camera installed, both connected to the revers light and ignition if I am not mistaken.
+ I have an auto dimming mirror, front camera and a accident record camera installed to the ignition.
+ I want to change my stock radio, will be connected to the original wires of the stock radio.
+ I want to upgrade my DRL wiring and connect it to the ignition.

As you can see the dealer scared me a bit, please help me with my questions. Because I don't want to buy the next ECU for my car because of voiding any warrenty by installing aftermarket.

Thanks a lot for reading,...


----------



## obermd (Mar 3, 2012)

Aftermarket electronics, if improperly installed, can indeed damage the electrical system of a car. If installed correctly there is no problem with most aftermarket equipment. One thing though, I'd be very careful replacing the stock radio head unit - GM uses this as an integral part of the car's security and control systems.

Looking at your list, I wouldn't install to the ignition. I would use the passenger compartment fuse box which is powered off 10 minutes after the car is turned off. Tapping into existing circuits is very fraught with issues such as pulling too much power which can cause under voltages and excessive current draw, both of which are very dangerous to modern electronic equipment. This is probably what the sub-contractor who installed your DRLs did.


----------



## BruneiCruze (Aug 22, 2012)

@ obermd, thanks a lot for your advise,... I have changed the reverse camera, auto dimming mirror etc to the passenger compartment fuse box and used the power outlet fuse. The DRL are wired to the ingnition because I did buy a relay and thats what the installation manual for the relay says Daytime Running Light DRL Relay Harness Auto Control on Off Switch | eBay I hope this won't blow the DRL, because they blew when it was connected to the battery. I will still buy a new radio and pray it doesn't damage my electronics, but so far I didn't see any posts about radio issues.

With the new ECU my car drives much smoother now  

Well what I learned so for: do not connect anything to your car battery and fuse box next to the engine unless you have a sub con to pay for the damages.

Lets see if my set up survives, I'll keep you posted.

A good read:http://www.cruzetalk.com/forum/10-e...t-voiding-warrenty-how-much-can-i-change.html


----------

