P046B code meaning
Catalyst Temperature Sensor 1/2 Correlation Bank 2
Powertrain system Generic code P04xx codes Check engine light
What P046B means
Some engines measure the catalyst temperature with sensors instead of only modelling it. P046B compares catalyst temperature sensors 1 and 2 of bank 2 (the side without cylinder 1): both are electrically valid, but their readings do not match – for example they differ after a long stop, or the difference does not fit the operating state. No manufacturer document available to us uses this code; FCA's EcoDiesel has only one such sensor per bank, and most makers handle exhaust temperature sensors and their correlation under EGT codes such as P0544 ff or P24C2. The description follows CARB's plausibility requirement for input components.
P046B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P046B
- Check engine light on
- Usually no change in driving
- Diesel: filter regeneration possibly changed
Common causes of P046B
- Most likelyOne of the two sensors drifting (soot on the tip, ageing)
- PossibleSensors fitted or connected the wrong way round
- PossibleContact resistance at one sensor's connector
- Less likelyExhaust leak between the sensors
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Catalyst temperature sensor b2s1Catalyst temperature sensor b2s2Sensor wiringEngine control module
What each part of P046B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 6B | The exact fault in that area. |
What to do next
- Note P046B 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 P046B
What does P046B mean?
P046B means "Catalyst Temperature Sensor 1/2 Correlation Bank 2". Some engines measure the catalyst temperature with sensors instead of only modelling it. It is a generic code, so it means the same on every make.
Is it safe to drive with P046B?
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 P046B fail an emissions test?
Yes, it can. P046B 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 P046B to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P046B 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.