Powertrain, generic (extended)

P276B Electric/Auxiliary Transmission Fluid Pump B Motor Supply Voltage Circuit Low

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P276B is set when the supply voltage reaching the motor of auxiliary transmission pump B sags below its lower limit. Audi names this code in bulletin 34-17-25 (revision of September 2017) covering 2017 A4/A5/A6 models and the 2018 Q5 fitted with the 0CJ, 0CK or 0CL twin-clutch gearbox. Pump B there is the gear oil pump V553, and P276B00 may appear together with lost communication U28A00, stuck-on P27A600 and performance P27A300. The bulletin attributes a rattle from under the car to a supplier assembly issue and calls for a new pump with new bolts; transmission fluid must not reach the electrical connector during removal. Apart from that case, weak batteries, high-resistance grounds and partial shorts can pull the voltage down.

Likely causes

Defective gear oil pump V553 (Audi 0CJ/0CK/0CL)
High resistance in supply or ground of the pump
Low system voltage from a weak battery

Symptoms

  • Rattle noise from under the vehicle (Audi)
  • Transmission warning lamp
  • Further pump B codes stored

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,200
Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

aux trans pump bsupply circuitbattery

Related codes

P276AP276CP276DP27A3P27A6P0B0A

References: static.nhtsa.gov, law.cornell.edu.