P20D7: Exhaust Aftertreatment Fuel Supply Control Circuit/Open

Upstream of the exhaust doser sits a valve that releases fuel to it only when a regeneration is wanted, often called the shutoff or fuel cut valve. This code reports an open in its control circuit. Volvo and Mack store it as P20D713 (failure type 13 = open) and, in troubleshooting guide KC-2157, send the technician to the wiring and connector of the AHI module, where this valve is housed. Hino's J08E trucks use a fuel cut valve of the same kind. With the valve circuit open, no fuel reaches the doser and active regeneration stops. Shorts are P20D9 (low) and P20DA (high); mechanical sticking is P20DB and P20DC.

Symptoms

• Check engine light on
• Active regeneration not possible
• Soot warning, later reduced power

Most likely causes

• Loose or corroded connector at the dosing module
• Broken wire in the dosing module harness
• Open coil in the fuel shutoff valve

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and wiring
2. Check the continuity of the wire between the component and the control module.
3. Use live data to compare the reading with actual conditions
4. Measure power, ground, and signal
5. Replace the sensor if the circuit is good

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P20D7 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 0: Subsystem depends on the code range
• D7: Specific fault in that system

Frequently asked questions

Can I keep driving with code P20D7?

You can normally keep driving. If it affects the fuel level, do not trust the gauge and refuel earlier than usual.

What causes code P20D7?

The most common causes are: loose or corroded connector at the dosing module; broken wire in the dosing module harness; open coil in the fuel shutoff valve.

Related codes

• P20D9Exhaust Aftertreatment Fuel Supply Control Circuit Low
• P20DAExhaust Aftertreatment Fuel Supply Control Circuit High
• P20D8Exhaust Aftertreatment Fuel Supply Control Performance
• P20DBExhaust Aftertreatment Fuel Supply Control Stuck Open
• P20DCExhaust Aftertreatment Fuel Supply Control Stuck Closed
• P0005Fuel Shutoff Valve A Control Circuit/Open

Sources

• static.nhtsa.gov: MC 10209678 0001
• static.nhtsa.gov: MC 10216866 0001
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.