P06B4

Symptoms

• Check Engine Light Is On
• Group B sensor readings are too low
• Unstable engine operation
• Many associated sensor errors simultaneously
• Possible engine transition to emergency mode

Causes

• Short to ground in the circuit of one of the sensors of group B
• Faulty sensor with internal breakdown to ground
• Damage to group B wiring harness (chaining to body)
• Moisture getting into connectors causing leakage
• High contact resistance in the ECU power connector

How to Fix

1. Read error codes, identify group B sensors according to the diagram
2. Measure the voltage on the Group B power line (expected to be below normal)
3. Disconnect sensors one at a time until normal voltage is restored
4. Check the resistance of the identified sensor between power and ground
5. Replace the faulty sensor or repair the short in the wiring
6. Reset codes and ensure normal voltage level after repair

Related codes

Error P06B4 by Vehicle Brand