What it means
The voltage in sensor power supply A is above the expected range. This may affect components supplied by that circuit; which ones depends on the vehicle.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Sensor power supply A is a shared, module-managed rail for a vehicle-dependent set of sensors. P06B2 sets when its voltage is higher than expected, which can happen if the line contacts a higher-voltage source or the module's supply control is faulty.
Common causes
Most likely first.
- Supply line shorted to higher voltage
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
How to diagnose it
- Scan all modules and save freeze-frame data, noting faults from sensors that may share supply A.
- Check live data for those sensors to see whether several readings became abnormal at the same time.
- Inspect supply A wiring and connectors for chafing against a B+ source, corrosion, loose terminals, or evidence of moisture.
- Use the wiring diagram and manufacturer's procedure to measure supply A and check for a short to a higher-voltage circuit.
- If the harness and connected loads check out, test the module's supply A output against the manufacturer's specification.
Common fixes
- Secure a loose connector or repair poor terminal contact.
- Repair supply A wiring shorted to a higher-voltage source and protect its routing.
- Replace a failed sensor or branch component if testing shows it is driving the shared rail high.
- Repair or replace the module if its supply A output is confirmed to be faulty.
Can I keep driving?
Avoid extended or demanding driving until the cause is known, because excessive supply voltage can disrupt multiple sensors and engine control. Stop if the engine runs erratically, loses power, or warning messages multiply.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.