2006 Audi A4 2.0T stalls and won’t restart when hot after driving
I’ve got a 2006 Audi A4 2.0T. It runs fine until I drive about an hour, shut it off, then restart to leave. It starts, but as soon as I pull away it stalls and won’t restart until it cools down. I’ve replaced the in-tank fuel pump, PCV valve, and crankshaft position sensor, but it’s still happening.
This is classic for a failing fuel pump control module (J538) on these Audis. When it gets hot, it cuts power to the pump, causing a no-start until it cools off. You’ve already replaced the pump and crank sensor, so those are off the table. Runner-up would be the camshaft position sensor—sometimes they fail hot, but not as often as the module.
Most likely culprits
- Fuel Pump Control Module (J538) — Known to fail with heat soak, cuts fuel pump operation after a hot soak.
- Camshaft Position Sensor — Can fail when hot, causing no start, but you’ve already done the crank sensor.
How to narrow it down
- Next time it stalls hot, check for fuel pressure at the rail.
- No pressure = fuel delivery issue (likely the module).
- Listen for the fuel pump prime when key is turned on (after hot stall).
- No sound = module isn’t powering the pump.
- Scan for codes (even if CEL is off).
- Look for P0089, P2293, or fuel pressure regulation codes—these support a fuel delivery fault.
- Check for spark and injector pulse during hot no-start.
- If both are present, it’s not a cam/crank sensor issue.
- Feel the fuel pump control module (left rear trunk, under carpet) right after stall.
- If it’s hot to the touch, that’s a clue. Sometimes tapping it will let the car start.
Possible parts (if needed)
- Fuel Pump Control Module (J538)
- Camshaft Position Sensor (if no spark/injector pulse when hot)
A few questions
- When it won’t restart hot, do you smell raw fuel at the tailpipe after cranking?
- Have you checked for spark and injector pulse during the no-start?
- Any codes stored, even pending or history, after the stall event?
Let me know what you find on those checks. This is a safety-critical issue—don’t keep cranking if you smell strong fuel.