Scania EMS DTC 12 Control unit

EMS Engine Management System · Scania · 2 variants

Code 12 (decimal). Some diagnostic tools show it in hexadecimal as 000C.

In short

Incorrect or unreliable data.

Variant 1

Applies to: EMS S6 IoM singlespeed (S6IM)EMS S6EMS S6 (EMS S6 EuroIII)

What does Scania EMS fault code 12 mean?

Incorrect or unreliable data.

What causes Scania DTC 12?

Internal fault in the control unit.

How does the system react?

The engine cannot be started or run as long as the fault is active.

How to fix Scania EMS fault code 12?

  1. Clear the fault code memory and turn the power off and on with the starter key.
  2. Then check if the fault code has been generated again.
  3. Renew the control unit if this is the case.

Variant 2: Cam phaser for intake valve, slow forward response

Applies to: EMS10

Detection

The intake valve cam phaser response is slower than expected when changing position forward.

Possible cause

- Fault in the actuator. - Contaminated oil. - Oil pressure or supply to the cam phaser too low. - Debris in the cam phaser or control valve. - The control valve does not work - The torsion spring has come loose from the mounting point. - Fault with the cam phaser.

Symptoms

- The engine performance is affected. - Decompression braking performance may be affected. - May cause engine noise.

How to fix

  1. Check if there are other fault codes relating to the actuator.
  2. Check that the engine has sufficient oil pressure and that the oil is not contaminated.
  3. Visually check that the electric actuator is moving correctly.
  4. Visually check that the cam phaser control valve moves smoothly and does not jam in any position.
  5. See WSM > 01 Engine > 01-01 Cylinder Head > Cylinder Head [DOHC].
  6. Visually check that the torsion spring on the cam phaser is in the correct position.
  7. See WSM > 01 Engine > 01-01 Cylinder Head > Cylinder Head [DOHC].
  8. After repair, verify by running a cam phaser operational test.
  9. Renew the cam phaser and control valve if the fault persists.

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

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