Every morning my 2005 AUDI A6 3.2 with the engine cold, I start the vehicle and within 2 minutes (1 min. 45 seconds) she throws an ESP Fault with two codes P2296 (Fuel Pressure Regulator Valve;N276 Short to Plus and P1653 (Please check DTC Memory of ABS Controller). I could not find any other ABS codes. If I am accelerating when the Fault occurs I get a shutter, if I coast through it I don't feel much of an effect.

After she reaches full warm up and I turn it off/on she throws no more ESP Fault or codes and runs fine all day. Warm it up halfway and I get the Fault/codes again. If I clear the two codes they will not return the rest of the day otherwise the codes are stored even though she throws no more Faults. Next morning well, I hope you saw the movie, it's Groundhog Day again.

AUDI and I have attacked this going after the P2296 without success. AUDI cleaned throttle valve, replaced HPFP, rewired from connector to HPFP. I replaced fuel filter, replaced High and Low Fuel Pressure Sensors, cleaned carbon Intake Valves, replaced fuel pressure regulator valve, tried another throttle body. Result is no change.

I am becoming convinced the ESP Fault/codes are somehow related possible due to a bad connector. Any ideas?

 

There is a service bulletin for the abs pump/ module... This is a common problem and would turn on your esp/ brake/abs lights, possibly intermittently.. Might be worth checking into. Good luck!!

 

Problem was fixed with help on AUDIZINE.com, still running without a problem at 11/9/19. All steps posted on AUDIZINE.com. Groundhog Day - Short to Plus: P2296 and P1653 Good Luck.