P2046 code meaning
Reductant Temperature Sensor A Circuit Intermittent
Powertrain system Generic code P20xx codes Check engine light
What P2046 means
P2046 records short dropouts or jumps in the signal of reductant temperature sensor A. No manufacturer documents this code publicly. Deutz, the clearest user of the P2042 group, lists only an open line, a ground fault, both shorts and a plausibility error for this sensor, but no intermittent entry. How such a check can work is shown by GM's tank sensor test P205E in the 2025 DEF controller: it fails when the reading moves by more than 4 °C inside a ten-sample window, three times out of nine. CARB requires input circuits to be monitored for faults of this kind (1968.2, paragraph (f)(15.2.1)). In practice the cause is mostly a terminal losing contact under vibration or DEF residue in the connector. Wiggle tests with live data help; the tank sensor has its own code, P205E.
P2046 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2046
- MIL that comes and goes
- Unsteady DEF temperature in live data
Common causes of P2046
- Most likelyTerminal losing contact under vibration
- PossibleCorrosion from DEF residue in the connector
- PossibleHarness rubbing through intermittently on the frame
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant temperature sensorWiring harness
What each part of P2046 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 46 | The exact fault in that area. |
What to do next
- Note P2046 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 P2046
What does P2046 mean?
P2046 means "Reductant Temperature Sensor A Circuit Intermittent". P2046 records short dropouts or jumps in the signal of reductant temperature sensor A. It is a generic code, so it means the same on every make.
Is it safe to drive with P2046?
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 P2046 fail an emissions test?
Yes, it can. P2046 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 P2046 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2046 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.