Scania AMS DTC 8434 Downstream reductant dosing unit injection valve is stuck open

AMS AMS control unit · Scania

Code 8434 (decimal). Some diagnostic tools show it in hexadecimal as 0020F2.

In short

The system can not detect any injector needle motion on the downstream dosing unit.

Applies to: AMS2

What does Scania AMS fault code 8434 mean?

What causes Scania DTC 8434?

How to fix Scania AMS fault code 8434?

Read the full explanation with Premium

Causes, system reaction, symptoms and step-by-step repair instructions for every fault code are available to Premium members.

Full explanations of every code and brand
Causes, symptoms and repair steps
New brands and codes included

Get Premium – 7,50 € / month I already have an account

Yearly plan: pay 10 months, get 12. Cancel at any time.

This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.