My Audi A6 c6 2.7tdi won't start after siting for 1 day.

[AudiKolegaProblem]

Hello,

I have a problem with my Audi A6 C6, 2.7 TDI. After coming home from work, the next morning the car won't start. The engine cranks, almost as if it’s about to catch, but it doesn’t start.

The error codes that appeared:

• P3135 (012597)
• P2196 (008598)
• P0104 (000260)
• P0102 (000258)
• P0698 (001688)

According to the error descriptions, they relate to:

• Reference voltage sensor C
• 2x Mass air flow sensor
• Lambda sensor (Bank 1 - Sensor 1)
• Intake manifold control (Bank 1)

I have checked everything – replaced the sensors, measured voltages, everything seems fine, but the car still won’t start.

Any suggestions? Thanks in advance!