Powertrain, generic · Computer and auxiliary outputs

P06B4 Sensor Power Supply B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Despite the similar name, 'sensor power supply' is not the 5 V sensor reference (P0641 ff). It is documented in GM hybrid drive motor control modules: a 15 V supply that excites the motor position sensor (resolver) and powers the gate drivers of the inverter transistors, kept separate from the 5 V reference and the 12 V supply. In GM's 2008 Two-Mode hybrid, A and B are the two motor control modules. P06B4 means supply B, in the second motor control module, is too low: GM's 2008 Two-Mode hybrid flags below 12.0 V for 365 ms after two trips. Blown fuses, shorts in supplied components or an internal fault are typical. Mitsubishi's 2022 Outlander lists it as a sub-code.

Likely causes

Blown supply fuse
Supplied component or wire shorted to ground
Internal supply circuit faulty
Low 12 V system voltage

Symptoms

  • Check engine or hybrid warning light
  • Electric drive or hybrid mode limited or disabled
  • Further motor position or inverter codes

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–1,500
Time1–4 h

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

Parts involved

sensor power supply circuitdrive motor control moduleresolver

Related codes

P06B3P06B5P0651P0652P0653

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.