Sticking or worn fuel quantity adjuster solenoid or actuator; Contaminated or degraded diesel fuel causing internal pump wear; Restricted fuel supply, such as a clogged fuel filter or weak lift pump; Air intrusion into the fuel system, often from leaking seals or lines; Faulty wiring or connectors to the quantity adjuster or ECM; Internal wear in the injection pump causing the adjuster to reach its limit; ECM software calibration issue or corrupted adaptation values

DTC codes / Volkswagen codes / P1562

P1562 · VolkswagenQuantity Adjuster Upper Limit Attained

Q: What does code P1562 mean?

Quantity Adjuster Upper Limit Attained. P1562 on Volkswagen diesel engines indicates that the engine control module (ECM) has detected the fuel quantity adjuster reaching its maximum allowed upper limit of travel. The ECM commands the adjuster to increase fuel delivery, but the adjuster's feedback signal shows it has hit the mechanical or electrical stop, meaning the requested fuel quantity cannot be achieved.

P1562 on Volkswagen diesel engines indicates that the engine control module (ECM) has detected the fuel quantity adjuster reaching its maximum allowed upper limit of travel. The ECM commands the adjuster to increase fuel delivery, but the adjuster's feedback signal shows it has hit the mechanical or electrical stop, meaning the requested fuel quantity cannot be achieved.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyProfessional

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode, especially under acceleration or load
Rough idle or stalling when the engine is cold or under load
Hesitation or flat spots during acceleration
Excessive black smoke from the exhaust due to over-fueling attempts
Poor fuel economy or increased fuel consumption

Common causes, most likely first

Sticking or worn fuel quantity adjuster solenoid or actuator
Contaminated or degraded diesel fuel causing internal pump wear
Restricted fuel supply, such as a clogged fuel filter or weak lift pump
Air intrusion into the fuel system, often from leaking seals or lines
Faulty wiring or connectors to the quantity adjuster or ECM
Internal wear in the injection pump causing the adjuster to reach its limit
ECM software calibration issue or corrupted adaptation values

How to diagnose and fix it

Scan all modules for stored codes and freeze-frame data to confirm P1562 and check for related fuel system codes
Inspect the fuel quantity adjuster connector and wiring for corrosion, chafing, or loose pins
Replace the fuel filter and check for fuel supply restrictions or air leaks in the lines
Perform a fuel pressure and delivery test according to Volkswagen service procedures
Check and reset the quantity adjuster adaptation values using a factory-level scan tool
Remove and inspect the quantity adjuster for sticking or wear, replacing if necessary
If the adjuster and fuel supply are good, diagnose the injection pump for internal wear or replace the pump

Before you replace the injection pump

A clogged fuel filter or weak lift pump can cause P1562 without any fault in the quantity adjuster itself, so always verify fuel supply first.
Air bubbles in the fuel system often mimic a failed quantity adjuster because the adjuster hits its upper limit trying to compensate for aerated fuel.
The quantity adjuster adaptation values can drift over time; a simple reset with a factory scan tool may resolve the code without parts replacement.
P1562 is frequently misdiagnosed as a bad injection pump when the real issue is a chafed wire in the harness near the pump.
On some Volkswagen diesel engines, this code sets after a low-fuel run or fuel filter change because the system needs re-priming and adaptation.

Can I keep driving with P1562?

You can drive the vehicle cautiously to a repair shop, but avoid heavy acceleration, towing, or sustained high-speed driving because the engine may enter limp mode or stall unexpectedly. Prolonged driving with this code can damage the injection pump and exhaust system.

Tools that help

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Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.