P06B6 code meaning
Internal Control Module Knock/Combustion Vibration Sensor Processor 1 Performance
Powertrain system Generic code P06xx codes Check engine light
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. 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.
P06B6 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P06B6
- Check engine light
- Retarded ignition, less power and higher consumption
- Often no other symptoms
Common causes of P06B6
- Most likelyEngine module software (GM bulletin)
- PossibleInternal knock processor or test circuit faulty
- PossibleKnock sensor wiring with high resistance or intermittent contact
- Less likelyKnock sensor faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine control moduleKnock sensor
What each part of P06B6 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6 | Area: computer (engine control module) and output circuits. |
| B6 | The exact fault in that area. |
What to do next
- Note P06B6 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P06B6
What does P06B6 mean?
P06B6 means "Internal Control Module Knock/Combustion Vibration Sensor Processor 1 Performance". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P06B6?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P06B6 fail an emissions test?
Yes, it can. P06B6 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P06B6 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P06B6 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.