Scania EMD DTC 5870 Charge air temperature sensor T121

EMD EMD control unit · Scania · 2 variants

Code 5870 (decimal). Some diagnostic tools show it in hexadecimal as 16EE.

In short

Higher temperature than expected from the charge air temperature sensor.

Variant 1

Applies to: EMD0

What does Scania EMD fault code 5870 mean?

Higher temperature than expected from the charge air temperature sensor.

What causes Scania DTC 5870?

- Poor charge air cooler efficiency, which can be caused by packed snow or another object clogging the charge air cooler. - Problem with the cooling fan. - Fault in the charge air temperature sensor. - Fault in the temperature signal from the main mirror and wide-angle mirror heater element on the driver's side H2. Only applies to vehicles equipped with an EGR circuit: - Poor EGR cooler efficiency. - Leaks in the charge air system. - Leaking EGR valve.

How does the system react?

The fault affects the engine's nitrous oxide emissions. Depending on the emission class, this may result in torque reduction, speed limitation and a warning indication.

How to fix Scania EMD fault code 5870?

  1. Check that the charge air cooler is intact and fitted correctly.
  2. Check the cooling fan and its clutch.
  3. Measure the temperature with an external thermometer as close to the main mirror and wide-angle mirror heater element on the driver's side H2 as possible.
  4. Compare with the temperature value from the heater element.
  5. Check the harness-to-component connectors and cable harness of the charge air temperature sensor and the main mirror and wide-angle mirror heater element on the driver's side H2.
  6. Check that the charge air temperature sensor and the main mirror and wide-angle mirror heater element on the driver's side H2 are intact and have been fitted correctly.
  7. Measure the resistance across the charge air temperature sensor.
  8. Verification Drive the vehicle with the exhaust brake deactivated until the engine is at operating temperature.
  9. Drive another 20 minutes with a lot of coasting.
  10. Applies only to vehicles equipped with EGR circuit.
  11. If the fault remains, run Functions > Check > Powertrain > Engine > EGR system > EGR circuit leak testing.
  12. Check that the EGR cooler is intact, clean and fitted correctly.

Variant 2

Applies to: EMD1

Detection

Higher temperature than expected from the charge air temperature sensor.

Possible cause

Possible causes: - Poor charge air cooler efficiency, which can be caused by packed snow or another object clogging the charge air cooler. - Problem with the cooling fan. - Fault in the charge air temperature sensor. - Fault in the temperature signal from the main mirror and wide-angle mirror heater element on the driver's side H2. Only applies to vehicles equipped with an EGR circuit: - Poor EGR cooler efficiency. - Leaks in the charge air system. - Leaking EGR valve.

System reaction

The fault affects the engine's nitrous oxide emissions. Depending on the emission class, this may result in torque reduction, speed limitation and a warning indication.

How to fix

  1. Check that the charge air cooler is intact and fitted correctly.
  2. Check the cooling fan and its clutch.
  3. Measure the temperature with an external thermometer as close to the main mirror and wide-angle mirror heater element on the driver's side H2 as possible.
  4. Compare with the temperature value from the heater element.
  5. Check the harness-to-component connectors and cable harness of the charge air temperature sensor and the main mirror and wide-angle mirror heater element on the driver's side H2.
  6. Check that the charge air temperature sensor and the main mirror and wide-angle mirror heater element on the driver's side H2 are intact and have been fitted correctly.
  7. Measure the resistance across the charge air temperature sensor.
  8. Verification Drive the vehicle with the exhaust brake deactivated until the engine is at operating temperature.
  9. Drive another 20 minutes with a lot of coasting.
  10. Applies only to vehicles equipped with EGR circuit.
  11. If the fault remains, run EGR circuit leak testing.
  12. Check that the EGR cooler is intact, clean and fitted correctly.

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

Code 5870 in other Scania systems

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