Error code · Engine

P2046 — Reductant Temperature Sensor Circuit Intermittent

Don’t put off the repair

A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.

Possible causes

What you can do yourself

  1. Inspect the connector and wires: corroded terminals, chafed insulation. Clear the code and see whether it comes back.
  2. The sensor is usually built into the module in the AdBlue tank together with the level sensor and the heater. Check the module connector for corrosion and water.
  3. The control unit uses this sensor to switch on the heating: with this fault the AdBlue may not thaw in winter.
  4. If the fault isn’t fixed, after a while the engine will limit power or speed, and some cars won’t allow a restart. This is protection required by Euro 5 and Euro 6 rules: drive calmly to a service centre without delay.

Stop and don’t drive on if:

  • The Check Engine light is flashing
  • The temperature gauge is in the red or the overheating light is on
  • The red oil pressure light is on
  • Smoke from under the bonnet, a burning or petrol smell
  • Strong jerking, knocking from the engine, or the car barely moves
OOleg’s tip: check the connector

Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.

Unplug and inspect connectors with the ignition off.

The explanation comes from the error code reference in the AvtoElektrik PRO app.

Need a mechanic’s help?

Couldn’t fix it yourself? Oleg, an auto electrician, does computer diagnostics and repairs: he comes out anywhere in Almaty or sees you at his workshop.

Want to figure it out yourself?

Oleg’s course “Car computer diagnostics with a scan tool”: how to hook up a scanner, read codes and live data, and use them to find the cause. The first lessons are free.

Scan tool diagnostics course →

Nearby codes

All codes in P20xx →

Who keeps this reference

The reference is kept by Oleg Dmitriev, an auto electrician from Almaty with 26 years of experience: computer diagnostics of cars and trucks, repair of control units (ECUs). Can’t find the cause? Message him.