P06F2: Reductant Control Module Internal Temperature Sensor Circuit Low

What it means

Same as P06F0 with the signal voltage below the plausible range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

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 uses an internal temperature sensor to monitor its own operating temperature. P06F2 sets when the sensor signal falls below the plausible range, which can result from an internally shorted sensor or a fault in its wiring or connector.

Common causes

Most likely first.

1. Sensor internal short
2. Connector pins corroded - high contact resistance
3. Harness chafing through insulation

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 check live reductant-module temperature data to see whether the reading is implausibly low or changes when the fault returns.
2. Inspect the reductant control module connector for moisture, corrosion, damaged seals, or pins pushed back from their normal position.
3. Trace the sensor circuit harness for chafing or crushed insulation, especially near brackets and connector entry points.
4. With the wiring diagram, check the sensor signal and related circuit wiring for a short or abnormal resistance against the manufacturer's specification.
5. Wiggle the harness while monitoring the live temperature signal, then test the internal sensor and module only after external wiring and connector faults are ruled out.

Common fixes

• Clean and secure corroded or loose connector terminals, and replace damaged seals as needed.
• Repair chafed sensor-circuit wiring and protect it from rubbing again.
• Replace the reductant control module if its internal temperature sensor is confirmed shorted and not separately serviceable.
• Clear the code and confirm the temperature signal remains plausible through a cold start and warm-up.

Can I keep driving?

You can usually drive cautiously if the vehicle runs normally, but heed any AdBlue/DEF warnings because emissions-control faults can trigger a no-start countdown. Arrange diagnosis promptly and avoid ignoring a countdown or emissions warning.