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Water entered brain box, the fan turns but engine cannot start

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Electronic controls are extremely sensitive to shorting out if they get wet, so a replacement is probably only way to repair, and make sure you prevent water damage to new module.

Posted on May 02, 2015


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Posted on Jan 02, 2017

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SOURCE: my audi a4 1995 model cannot start

have you tried resetting alarm system...?

Posted on Apr 13, 2010

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SOURCE: my nissan sentra 2005 special

Sorry to say but you need another ECM due to water damage. Seal the next one up with sylicone to keep the water out and don't open it!!! There's nothing that YOU can fix inside of it,and that will just VOID the WARRANTY!

Posted on Jul 24, 2011

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What are the problems that can arise when water pure on brain box?

water shorts out the electronics and generally destroys the ECM
replace it with a new or known good unit

Mar 08, 2017 | Toyota Cars & Trucks

2 Answers

I have a 2007 patriot and the radiator cooling fan won't shut off. how do I fix it.

Funny usually it wont come on.
I should ask a question first is it on when the car is cold? just turn the key to on before you start the engine when it is cold and lift the hood to check.

If not then there could be lots of things. Engine always hot, worn water pump or thermostat not working properly, bad control relay.

You can check the control relay which is usually mounted on the lower rad support in between the grill and the rad. You should be able to see the relay it has fins on it.

Mar 06, 2015 | 2007 Jeep Patriot Sport

1 Answer

Replaced brain box on 2000 dodge neon but still wont start

did the check engine light tell you there was a pcm fault or something else before you did the swap? Alot of things can cause a no start. A bad crank position sensor(CKP) cam position sensor(CMP) fuel pump. My brother-in-law did that to a dynasty and turned out to be a broken wire on the CKP circuit.

Jun 04, 2013 | Dodge Cars & Trucks

2 Answers

Can a faulty brain box stops d car engine from turning on

brain box it a broad statement no current to plugs could be one of two or three different problems giving the same result

Jun 04, 2012 | 1998 Toyota Camry

1 Answer

My nissan sentra 2005 special edition does not rev. when i change the brain box it revs alright. i opened the brain brain box trying to fix it then i realised water has entered, i cleaned it but still does...

Sorry to say but you need another ECM due to water damage. Seal the next one up with sylicone to keep the water out and don't open it!!! There's nothing that YOU can fix inside of it,and that will just VOID the WARRANTY!

Jul 24, 2011 | 2005 Nissan Sentra

1 Answer

My chrysler cirrus 2000 model is not starting, a mechanic said the brain box is bad, we have tried over 7 other brain box without any luck, what can i do to get the car working?

It seems that if you tried that many brain boxes, one of them would have worked.

Here are some things to check. (I am assuming you have gas in the tank, the battery is good and the engine cranks over but doesn't catch and run.) Perhaps one of these items was overlooked in the trouble-shooting:
Engine cranks but won't start:
Charcoal canister full of fuel, faulty MAP or MAF sensor, faulty engine coolant temp sensor, faulty EVAP canister vent valve, EGR valve stuck open, lack of or incorrect fuel pressure (fuel filter, fuel pump, fuel pump relay), water in fuel, fouled spark plugs, faulty ignition module, severe vacuum leak, severely clogged fuel injectors, wrong size o-rings on fuel injectors (prevents compression), faulty airflow sensor (if equipped), Idle Air Control (IAC) valve defective, disconnected-broken-loose wires for all of the above.

Feb 09, 2011 | Chrysler Cirrus Cars & Trucks

2 Answers

2001 PT cruiser overheating.

Note that you will not damage anything unless you don't turn it off when it gets too hot.

So start the car and let is idle to get warm - have the hood open and see if the fans come on. If the temp goes past normal and fans do not kick on, it's usually the fan relay (~$20) - these usually sit in the engine compartment fuse box. Also check the fan fuses - there should be two of them. If that doesn't work, then it would be the temp sensor.

However if your heater is blowing cold when the car is warm, sounds like there is an air-lock. This happens if you don't 'burp' the cooling system properly after flushing the system. Easiest way to check on this is if either the lower or upper radiator hose is not hot when the engine is hot.

Incidentally, if the thermostat is shot, you would not be able to 'burp' the system properly.

My bet is either the thermostat or airlock - or both.

Jul 31, 2010 | 2001 Chrysler PT Cruiser

1 Answer

Car overheats

Hey Alex ! Try this. Make sure the fan does not turn on for any reason.
-Lift hood
-Start car
-let engine get hot
-observe as engine gets hot just sitting there idleing if at any time the fan switches on.
as the engine gets very hot...may take 7-10minutes....the fan should switch on.

If not, check the switching box for the fan itself; it has a brain box that controls when the fan turns on.
Its kinda like a thermostat, but the one you are familiar with just open to let coolant flow, not telling
the fan to switch on...its different.
You can take the hot wire from the fan and hook it directly to battery power. this will rule out
the fan's motor is good to begin with. otherwise check all the fuses that drive the power to the fan.

Jun 22, 2009 | 1995 Pontiac Grand Am

1 Answer

Car ran hot and shut down.

The tempreture is above the normal temperature required by the engine there by the coolant sensor will comunivate to the brain box when it is too hot to stop the engine, allow it to cool completely,then bleed the water for the excess air to leave the block engine and the radiator, then try starting,if it does not affect the top cylinder gasket it will return to normal, but also chek for leakage very well.

Dec 04, 2008 | 1999 Lincoln Continental

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