P06F0: Reductant Control Module Internal Temperature Sensor Circuit

What it means

A general circuit fault on the internal temperature sensor of the reductant control module.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The reductant control module manages parts of the diesel exhaust fluid (DEF, also called AdBlue) aftertreatment system and monitors its internal temperature sensor circuit. P06F0 sets when that circuit has an electrical fault, so the module may be unable to determine its own temperature correctly.

Common causes

Most likely first.

1. Reductant control module internal temperature sensor or circuit fault
2. Module power or ground problem
3. Damaged wiring or connector
4. Control module fault

Symptoms

• Check engine light or NOx warning on
• AdBlue/DEF level or quality warning
• Possible no-start countdown after ignore period
• Failed emissions inspection (NOx)

How to diagnose it

1. Record freeze-frame data and scan the engine and reductant modules for related temperature-sensor, DEF, power, ground, and communication faults.
2. Inspect the reductant control module connector and nearby harness for water, corrosion, damaged insulation, loose pins, or pin push-back.
3. Check module power and ground under the conditions specified by the manufacturer before testing the sensor circuit.
4. Test the internal temperature sensor circuit at the module connector for opens, shorts, or poor connections using the wiring diagram and manufacturer's specification.
5. If the external wiring and module supplies pass, follow the manufacturer's procedure to assess the internal sensor and reductant control module.
6. After repair, clear the faults and check for remaining DEF or NOx warnings and any required system reset.

Common fixes

• Repair damaged or corroded wiring and connector terminals at the reductant control module.
• Restore a faulty module power or ground connection.
• Repair an open or short in the internal temperature sensor circuit if the fault is in the harness.
• Replace the reductant control module if its internal sensor or circuitry is confirmed faulty.
• Complete any required reset or relearn and verify that DEF and NOx warnings clear.

Can I keep driving?

The vehicle may remain driveable at first, but an unresolved reductant-system fault can bring a warning or a no-start countdown, depending on the vehicle. Check the dashboard for countdown messages and arrange repair promptly; do not assume the vehicle will continue starting indefinitely.