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Skoda Octavia 1.6 2004 - Cooling fans come on, code 17069 - Fixed #

Posted by Nick Favell on May 8, 2015, 9:42 am

Year of Manufacture *: 2004
Engine Size and Code *: 1598
( Optional ) ECU Type: Bosch 0261s02036

Octavia 1600 petrol

Customer brought this in, intermittent non start and battery going flat. AA tested and condemned battery. New battery now fitted and tested ok.

About 20 minutes after the engine is turned off, the cooling fans start to run. Initially we found the engine control relay was hot, also fault code 17069 - PCM power relay open circuit.
We replaced the relay and cleared the DTC which has not returned. Starting now seems ok.
But fans still coming on about 20 minutes after switching off and locking the car. These continue to run until the battery is flattened.

visibly the wiring looks good. No chafing anywhere etc.

Is this a problem anyone else has had?

Re: Skoda Octavia 1Z. Cooling fans come on

Posted by Tom Yates <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2826' width='330' height='300' border=0 style='border:none;'> on May 8, 2015, 7:52 pm, in reply to "Skoda Octavia 1Z. Cooling fans come on "
Tom Yates

Hi Nick
Have you done a full system test, to check for any other related faults in other systems CAN faults and so on

Re: Skoda Octavia 1Z. Cooling fans come on

Posted by andrew pethig <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3731' width='330' height='300' border=0 style='border:none;'> on May 8, 2015, 9:13 pm, in reply to "Re: Skoda Octavia 1Z. Cooling fans come on "
Andrew Pethig

golfs and passats do this, they have a fan control module, which goes wonkey.

pull up a wiring diagram and chase the fault this way

Re: Skoda Octavia 1Z. Cooling fans come on

Posted by Jon Morgan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3190' width='330' height='300' border=0 style='border:none;'> on May 9, 2015, 9:27 am, in reply to "Re: Skoda Octavia 1Z. Cooling fans come on "
Jon Morgan

Scope the signal wire from the PCM to the fan ECU when the fault occurs to see if the fault is a command issue or internal fan ECU fault.

Fan control unit is integral in the large Fan motor housing.

These can spool up due to loss of engine comm's, faulty fan controller, water in engine fuse box etc....

Scoping the pwm from the engine will tell you whether the fan is being asked to run or has declared it's independence & is doing what it has a whim to do with no external input.

Fixed #

Posted by Nick Favell on May 22, 2015, 2:04 pm, in reply to "Re: Skoda Octavia 1Z. Cooling fans come on "
Edited by board administrator May 26, 2015, 2:08 pm

Ok so after a bit of digging around I got to bottom of this one.

Obviously at some point the under bonnet fuse box lid has been incorrectly fitted. Water ingress into the fuse board causing problems.

I wasn't entirely convinced so rather than stick a new fuse board on, I was able to strip this one down by separating the 'sandwiches', clean and dry everything, refit = all good now.

Allow about 2 - 2 1/2 hours to strip, dry and clean, take a few digital/phone pictures before pulling all the pins out. If you like 3D jigsaws you will like this job.

I did have it sitting in the airing cupboard for 2 days (without telling the wife) but that didn't dry out out properly.

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