2001 Audi A4 Crank but no start
Asked by Hunter May 20, 2017 at 05:47 PM about the 2001 Audi A4 1.8T quattro AWD
Question type: Maintenance & Repair
I just got an Audi A4 Quattro with the 1.8t.The car cranks but dose not start.
What Ive done
- Replaced Cam Sensor
- Replaced Plugs
- Checked ALL Fuses
- Replaced ECU Relays and fuses
- Checked Fuel Pressure
- Checked Compression
- Checked TIming and TIming belt.
- Unpluged and cleaned connector to every sensor
- Cleaned EVERY Grund connection
- Looked foor codes (None)
- Unpluged and Replugged in ECU
- Disconnected battery for 5+ minutes
- Checked all fuseable links.
Still cranks but dosent start.
Recently noticed I have no spark with only 2volts at the coils.
According to the guy I bught the car from it broke the serpentine belt
(replaced) and has ran since. He said he pulled and cleared a P0011 code.
I did an oil change and made sure all fluids where proper level.
Battery has been on battery tender for entire time ive had the car.
Check engine light is on when key is on but off when cranking.
6 Answers
Gtechimports answered 6 years ago
I guess the real question would be is the spark the only thing that is missing? If so those years i think had ignition control unit by the air box which can go out and give problems. If you don't have anything like that i would suspect some kind of electrical wiring fault either bad ground or power supply to ignition coils or engine control unit faulty. Google this part number and see if there is a part like that around air box. 8D0 905 351, Ignition Control Unit Good luck!
My first thoughts were either degraded wiring or possible crank sensor issue but my but I think i will too vote for a bad ICU module as mentioned above. So two votes for now on that :D Good Luck!
Finally pulled a code P0685 PCM Relay Open Already replaced that relay. Found only 1 volt at both fuse 29 and 34
Found this on one of the Audi forums. Would verify with a shop manual or contact one of the Audi experts on here "They were only on AEB engines not . ATW engines". up to 1999.5 You can do a basic ohm test on the crank sensor or test voltage output. The only way specifically to check this would be with a scope. You may have to take this one in for evaluation since it may be one or more issues going on such as crank sensor, ECU, or even a anti-theft lock out issue I know you mentioned the battery is o.k. but the actual cranking amps may not be quite up to par and that would require a hand held tool to do a proper check on that. Would be nuts if it was a simple as a charging issue but I have seen problems similar to this with that outcome. My last bit of advice is unplug the maf sensor and see if that makes any difference. Good Luck!
Fuse 29 has 1 volt......
My guess would be the crank shaft position sensor if there is no spark. My understanding is that the cam shaft sensor causes no fuel and the crank shaft position sensor causes no fuel or spark. I just went through it with mine. The fuel system all worked but it just won't flip the fuel pump relay which is why your showing low voltage. Even if you try to force jump it it will not work. It was the last thing I would've guessed honestly but sure enough crank shaft position sensor!
