2003 Audi A4 EPC System

ALLENMP

MEMBER
2003 AUDI A4
4 CYL
2WD
AUTOMATIC
60,000 MILES

Hi
The Engine starts immediately, idle is irrattic and then it stalls about 30 seconds latter. This condition is consistent.

The plugs have carbon build up as the engine is not getting enough air, the Throttle butterfly valve is not opening when engine is running.

When the key is on and the engine is not running, The throttle butterfly valve follows the gas pedal. When the engine is running, the butterfly does not move at all when the gas pedal is moved.

Replaced the brake light switch and no improvement.

I am totally stumped as I have no engine light, no EPC light and no DTC codes.

Mark

3 Replies

KHLOW2008

MECHANIC
41,815 POSTS

Hi Mark,

Thank you for the donation and sorry for the delay in answering.

Before proceeding with troubleshooting I need some additional info to do reserach.

Is the engine 1.8 or 2 liter?
Did you check if the brake switch is working correctly?

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Thursday, March 26th, 2009 AT 10:55 AM

ALLENMP

MEMBER
2 POSTS

It is a 1.8 engine.

Yes the brake switch did not actuate consistently. The rear lights would not always turn on and off consistently. I did buy a new switch and install it. It looks like they had a design change as the new switch looks more durable.

The car still sits as I cannot find another diagnostic path to go down at his point.

Mark

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Saturday, March 28th, 2009 AT 8:39 AM

KHLOW2008

MECHANIC
41,815 POSTS

Hi Mark,

Sorry if I did not make myself clear.
After replacement of the brake switch, are the brake lights working correctly?
Is the replaced switch of the correct specifications?
Is the adjustment of the brake switch correct?

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Saturday, March 28th, 2009 AT 10:48 AM