Variant 1
Applies to: EMS S6EMS S6 (EMS S6 EuroIII)
What does Scania EMS fault code 8707 mean?
The voltage from the charge air cooler pressure sensor has been implausible when compared with other pressure sensors, or there has been an implausible pressure change in relation to the current operating conditions.
What causes Scania DTC 8707?
Possible causes: - The intake system is blocked or leaking. - The charge air pressure sensor may be clogged up with oil. - There is a fault in the turbocharger. - Fault in the circuit of the coolant temperature sensor, charge air temperature sensor, fuel supply pressure sensor or fan speed sensor.
How does the system react?
There is a common voltage supply for the coolant temperature sensor, charge air pressure sensor, charge air temperature sensor, fuel supply pressure sensor and fan speed sensor. If a fault occurs in one of the sensors, the other sensor circuits may be affected. If the fault occurs, the control unit uses a pre-programmed value. The engine responds more slowly than normal to throttle actuation. This is because the smoke limiter is not operating correctly. For engines with EGR, the engine runs with EGR but without any feedback from the mass flow sensor. This means that the control unit only makes a rough adjustment of EGR content using predefined values for the position of the EGR damper. Calibration of the mass flow sensor is switched off.
How to fix Scania EMS fault code 8707?
- Check the coolant temperature sensor, charge air pressure sensor, charge air temperature sensor, fuel supply pressure sensor and fan speed sensor, along with the circuits' harness-to-harness connectors and electrical cables.
- Clear the fault code memory and check whether the fault remains.
- If the fault remains, check that the intake system is free from leaks and is not blocked by e.g. ice or debris.
- Also check that the air bellows are free of faults and are not squeezed together.
- Check the turbocharger.
Variant 2: NOx sensor T131, voltage too low
Applies to: EMS10
Detection
The voltage measured in NOx sensor T131 is too low.
Possible cause
Internal fault in NOx sensor T131.
How to fix
- Renew NOx sensor T131.
- Clear the fault code.
Variant 3
Applies to: EMS S6 IoM singlespeed (S6IM)
Detection
The voltage from the sensor has been implausible when compared with other pressure sensors, or there has been an implausible pressure change in relation to the current operating conditions.
Possible cause
The fault may have arisen because the intake system is blocked or leaking. The charge air pressure sensor may be clogged up with oil. The fault may have arisen because the turbocharger is not functioning correctly.
System reaction
If the fault occurs, the control unit uses a pre-programmed value. The engine responds more slowly than normal to throttle actuation. This is because the smoke limiter is not operating correctly. There is a common voltage supply for the coolant temperature sensor, charge air pressure sensor, charge air temperature sensor and the extra analogue input. If a fault occurs in one of the components, this can affect the circuits of the other components.
How to fix
- Check the circuit components, harness-to-harness connectors and electrical cables.
- Clear the fault code memory and check whether the fault remains.
- If the fault remains, check that the intake system is free from leaks and that it is not blocked by ice or debris for example.
- Also check that the air bellows are free of faults and are not squeezed together.
- Check the turbocharger.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.