Scania EEC DTC 4121 Exhaust gas temperature sensor upstream of the particulate filter

EEC Exhaust Emission Control · Scania

Code 4121 (decimal). Some diagnostic tools show it in hexadecimal as 1019.

In short

The exhaust gas temperature sensor upstream of the particulate filter indicates incorrect values.

Applies to: EEC3

What does Scania EEC fault code 4121 mean?

The exhaust gas temperature sensor upstream of the particulate filter indicates incorrect values.

What causes Scania DTC 4121?

Fault in the exhaust gas temperature sensor upstream of the particulate filter.

How does the system react?

A fault message is sent to the EMS control unit.

How to fix Scania EEC fault code 4121?

  1. The three exhaust gas temperature sensors of the exhaust gas aftertreatment are connected to the same circuit in a common module.
  2. In the event of a fault in one of the exhaust gas temperature sensors, the module for all exhaust gas temperature sensors has to be renewed.
  3. Renew the exhaust gas temperature sensor module upstream of the particulate filter.

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

Code 4121 in other Scania systems

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