P2B42 code meaning
A Camshaft Position Actuator Position Sensor B Circuit High Bank 1
Powertrain system Generic code P2Bxx codes Check engine light
What P2B42 means
Here sensor B of the bank 1 intake actuator reports a value stuck above its upper limit. Typical reasons are an open sensor ground, a signal line touching 5 V or battery voltage, or a defective sensor. No manufacturer explains P2B42 publicly; the supplier list from NTN-SNR only names it as the inlet-side sensor B with a signal that is too high. GM measures the related sliding-cam circuits of its L3B (P2C08) for contact with supply voltage while the output is switched off, again at 0.5 Ω and 4 of 5 samples, and lights the MIL on the first trip – a comparison, not a statement about this code. On Mercedes CAMTRONIC engines the sensor sits in the actuator, so a failed sensor means replacing the actuator. Low is P2B41.
P2B42 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B42
- Check engine light on
- Intake lift change locked out
- Usually no noticeable change in driving, sometimes reduced power
Common causes of P2B42
- Most likelySensor ground open or connector corroded
- PossibleSignal wire shorted to 5 V or battery voltage
- PossibleSensor (actuator) faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
A camshaft position actuator pos sensor b b1Wiring harnessECM
What each part of P2B42 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 42 | The exact fault in that area. |
What to do next
- Note P2B42 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 P2B42
What does P2B42 mean?
P2B42 means "A Camshaft Position Actuator Position Sensor B Circuit High Bank 1". Here sensor B of the bank 1 intake actuator reports a value stuck above its upper limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B42?
Drive gently and only to a workshop. With P2B42 the car can go into limp mode (reduced power) to protect itself.
Will P2B42 fail an emissions test?
Yes, it can. P2B42 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 P2B42 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2B42 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.