Author Topic: Odd fault codes, any ideas  (Read 794 times)

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Offline Caine

  • Posts: 2
Odd fault codes, any ideas
« on: July 22, 2016, 04:22:13 pm »
My A3 has been parked up waiting for a window regulator repair, had this sorted last night and had to jump start the car after sitting for two months ( battery was removed and trickled charged 2 weeks ago). Took it for a drive last night.

1. The engine temp gauge didn't get over 60*
2. The ac fan would not blow air, but warm air can be felt coming out of vents.
3. This morning while driving it into work, the PRNDS lights were flashing. This has now stopped, but weird.

I have had the battery tested this afternoon, and it's fine holding charge, correct volts etc.

Anyone have any ideas?

Offline midroad

  • Posts: 12
Re: Odd fault codes, any ideas
« Reply #1 on: July 30, 2016, 09:45:03 pm »
Hi there,

Do you have an OBDII scanner at all?

There appears to be two separate issues:

1.) Your transmission is in limp mode.
2.) Your engine thermostat has seized open, or the temperature sensor has failed, or the cabin fan motor has worn out its brushes.

Regarding issue 1:

This is serious. You need to get the transmission inspected immediately, and at the very least you'll need to replace the transmission fluid and filter. Catastrophic damage may occur if you continue to drive it as it is.
Your transmission's fluid filter is probably blocked. This is very bad.

Regarding issue 2:

Engine coolant thermostats eventually fail to work correctly - they are a general maintenance item.
If your coolant hasn't been replaced (flushed / drained / renewed) any time within the last year or two years, it is likely that corrosion has taken its toll and caused your thermostat to seize up and stop operating normally.

The thermostat is easy to replace. You should go ahead and do it.

Further note regarding issue 2:

Your coolant temperature sensor may have failed, which results in the dash cluster temperature gauge never rising above 60, irrespective of the actual coolant temperature.
If the coolant temperature sensor in the top radiator hose in front of your engine has a green connector, it is one of the known units from a bad batch and should be replaced. The good replacements have a white connector.
This is a low cost item and you should go ahead and replace it if you're sure it's not the thermostat.

Further note regarding issue 2:

If the cabin blower fan refuses to spin irrespective of controller settings, you need to consider three issues:
1.) The blower fan motor has used up its brushes. It happens.
2.) A fuse is blown or there's water in somewhere there shouldn't be. Use a multimeter to see what's going on at the blower motor.
3.) The coolant temperature isn't getting warm enough (see above re thermostat) or the heater core itself is blocked up and not exchanging enough heat to air to convince the controller to ramp up the fan or open the flap.

Final note regarding issue 2:

1.) Is the coolant level correct?
Add distilled water and / or the correct anti-freeze to top up the level. The red orange stuff is organic acid technology anti-freeze and should not be mixed with the green anti-freeze, and likewise vice versa. Green mixed with red antifreeze equals grey glycol sludge, and a blocked cooling system.

2.) Have you bled air out of the cooling system?
Lookup the recommended air bleeding methods.
Don't open the coolant reservoir if the engine is in any way warm. (Burns may result otherwiwse).

Hope this helps?
« Last Edit: July 30, 2016, 09:58:32 pm by midroad »

Offline SG

  • Posts: 66
Re: Odd fault codes, any ideas
« Reply #2 on: August 10, 2016, 10:41:47 pm »
If I were you I'd not do a thing until I had the car scanned.