Variant 1
Applies to: EMS S7
What does Scania EMS fault code 312 mean?
The lambda sensor diagnostics function produces a deviating value.
What causes Scania DTC 312?
The lambda sensor is shorted to the battery voltage.
How does the system react?
The engine's torque is reduced to protect the engine.
How to fix Scania EMS fault code 312?
- Check lambda sensor T154 as well as the harness-to-harness connectors and electrical cables.
- Renew lambda sensor T154.
- To verify that the fault has been rectified:
- Start the engine and run at a minimum of 1,000 rpm.
- The fault code then becomes inactive.
- Clear the fault code and check that it is not regenerated.
Variant 2
Applies to: EMS S8
Detection
The lambda sensor diagnostics function produces a deviating value.
Possible cause
The lambda sensor is shorted to the battery voltage.
System reaction
The engine's torque is reduced to protect the engine.
How to fix
- Check lambda sensor T154 as well as the harness-to-harness connectors and electrical cables.
- Renew lambda sensor T154.
- To verify that the fault has been rectified:
- Start the engine and run at a minimum of 1,000 rpm.
- The fault code then becomes inactive.
- Clear the fault code and check that it is not regenerated.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.