What P06B6 means
To detect an open knock sensor circuit, GM's engine modules feed a 20 kHz test signal into the sensor circuit and check whether it returns.
How the engine computer detects it
P06B6 checks the internal test circuit or knock signal processor for sensor 1: it sets when the returned 20 kHz component lies between the open-circuit thresholds, so the module cannot decide 'connected' or 'open'. GM rates it type B (two trips), type A in some 2025 modules; Saab retards ignition timing as a reaction. GM bulletin 22-NA-229 calls for reprogramming only, not part replacement. Ford uses P06B6 for lost communication with its knock chip (more than 200 cylinder events). Knock sensor circuit codes are P0325–P0328.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light
- Retarded ignition, less power and higher consumption
- Often no other symptoms
Common causes
- Engine module software (GM bulletin) Most likely
- Internal knock processor or test circuit faulty Possible
- Knock sensor wiring with high resistance or intermittent contact Possible
- Knock sensor faulty Less likely
How to diagnose P06B6
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: engine control module, knock sensor.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 6
- Computer and output circuits
- B6
- Specific fault
Questions drivers ask
Can I drive with code P06B6?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P06B6?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P06B6 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.