P2062: Reductant/Regeneration Supply Control Circuit/Open

What it means

The control line that energises the DEF supply pump or regeneration heating circuit is open — no continuity through the load or harness.

At a glance

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

How it works

This code covers a control circuit for reductant supply or regeneration, depending on the vehicle’s system design. The module checks whether the commanded circuit has electrical continuity through its load and wiring. P2062 sets when the circuit is open, so the DEF supply pump or regeneration heater may not operate.

Common causes

Most likely first.

1. Open winding
2. Open wire
3. Pin pushed back out of connector body

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. Save freeze-frame data and check for related reductant supply or heating codes to identify which system reported the open circuit.
2. Use the vehicle's wiring diagram to identify the affected load, connector and circuit before testing.
3. Inspect the load connector for a pushed-back pin, corrosion, damage or a disconnected plug.
4. Check the relevant harness for breaks or damage, then test continuity through the circuit and load as specified by the manufacturer.
5. If the wiring is intact, test the supply pump or regeneration heater and its control path using the manufacturer's procedure.

Common fixes

• Reconnect a loose plug or correctly seat a pushed-back terminal.
• Repair an open or damaged wire in the affected circuit.
• Replace a corroded or damaged connector.
• Replace the open pump or heater winding if testing confirms an internal break.

Can I keep driving?

The vehicle may continue to run, but DEF delivery or system regeneration may be impaired and NOx emissions can increase. Arrange a repair soon and watch for an SCR warning or no-start countdown.