From Ross-Tech Wiki
17036/P0652/001618 - Sensor Reference Voltage B: Too Low
- Wiring/Connectors from/to Intake Manifold Pressure Sensor (G31) faulty
- Intake Manifold Pressure Sensor (G31) faulty
- Engine Control Module faulty
- Check Wiring/Connectors from/to Intake Manifold Pressure Sensor (G31)
- Check/Replace Intake Manifold Pressure Sensor (G31)
- Replace Engine Control Module
- When found in 1.9l TDI (BEW):
- Check Atmospheric Pressure (MVB 010.2) and Intake Manifold Pressure Sensor (MVB 010.3). Compare both Values with Engine OFF, the Tolerance should be +/- 50 mbar.
- Check Variable Nozzle Turbocharger (VNT). Specifically, check the electronic actuator position sensor G500 , including unplugging it for testing.
- When found in other engines:
- Check the factory repair manual since this fault can point to problems with several different sensors.
- Specifically in the BLB engine, faulty MAF wiring can trigger it.