P06F3

What it means

P06F3 means the reductant control module (the control unit that manages the SCR or AdBlue dosing system on diesels) has seen a signal from its own internal temperature sensor that is higher than the expected range. Because the sensor is inside the module, the fault points to the module, its power and ground supply or its operating conditions rather than a separate sensor. The exact location and layout of the module vary by model and engine.

Symptoms

• Engine management or emissions warning light on
• AdBlue or exhaust fluid system warning message on the dash
• Reductant dosing reduced or stopped, so NOx emissions may rise
• Possible countdown warning to a restart inhibit or reduced power on some vehicles
• Other reductant or SCR system codes stored alongside it
• Fault may appear only after the vehicle has been hot or working hard

Possible causes

• Internal fault in the reductant control module reading its own temperature incorrectlylikely
• Poor or intermittent power or earth supply to the module, including corroded or loose connectionslikely
• Module genuinely overheating from nearby exhaust heat, damaged heat shielding or high ambient temperaturepossible
• Water ingress or corrosion in the module connector or housingpossible
• Outdated or faulty module software, where the manufacturer has identified this as a cause for the vehiclepossible
• Low or unstable battery or charging system voltage affecting module readingsrare

How to diagnose

1. Read all stored and pending codes and note any other reductant, SCR, NOx sensor or supply voltage faults
2. Review freeze frame data for engine temperature, vehicle speed and battery voltage when the fault set
3. Inspect the module, its mounting and connector for heat damage, water, corrosion, bent or pushed-back pins
4. Check battery condition and charging voltage, as low or erratic voltage can upset module readings
5. Check the module power feeds and earths for voltage drop under load, following the model wiring diagram
6. Check heat shields and the routing of nearby exhaust parts, and see whether the module is exposed to abnormal heat
7. With the vehicle cold, compare the module's reported internal temperature in live data with ambient temperature to see if it is implausibly high
8. Look up manufacturer service information for software updates or known issues on this model and engine

How to fix

• Clean, repair or replace corroded or damaged connectors, terminals and wiring to the module
• Repair power or earth supply faults and correct any battery or charging problems
• Refit or replace missing or damaged heat shielding and correct any heat source affecting the module
• Dry out and seal the connector area, and replace the module if water has entered it
• Update the module software if the manufacturer lists an outdated calibration as a cause for this vehicle
• Replace the reductant control module if it still reports a high temperature after supply and heat issues are ruled out, then code and adapt it as the manufacturer requires

Can I keep driving?

Nearby codes

• P06F2GenericReductant Control Module Internal Temperature Sensor Circuit Low
• P06F4GenericStop-Start Mode Lamp Control Circuit