Scania EME DTC 5874 T115 NOx sensor downstream of the SCR catalytic converter

EME EME control unit · Scania

Code 5874 (decimal). Some diagnostic tools show it in hexadecimal as 16F2.

In short

NOx sensor T115 downstream of the SCR catalytic converter measures too low a value.

Applies to: EME1

What does Scania EME fault code 5874 mean?

NOx sensor T115 downstream of the SCR catalytic converter measures too low a value.

What causes Scania DTC 5874?

- The NOx sensor is fitted outside the exhaust flow. - Urea deposit in the mixing chamber. - Defective NOx sensor. - Leakage from the V117 reductant doser. - Fault in the measurement of the gas flow. - Incorrect quantity of fuel injected. - Exhaust gas leakage between the reductant doser and silencer. Note: If the NOx sensor is subsequently fitted outside of the exhaust stream the applicable legislation cannot be met.

How does the system react?

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

How to fix Scania EME fault code 5874?

  1. Check that the NOx sensor is fitted correctly.
  2. Check EMS fault codes related to charge air pressure and fuel.
  3. Check the reductant circuit:
  4. Check that the reductant doser is metering the correct volume of reductant, run Exhaust gas aftertreatment, troubleshooting the liquid components of the SCR system > Metering test.
  5. Check that the reductant doser is not leaking reductant into the silencer; run Leak test for reductant doser.
  6. Visually check whether the mixing chamber for the reductant is blocked or damaged by urea deposits.
  7. Run Visual check of urea deposits.
  8. If there is a blockage in the mixing chamber:
  9. Run Internal cleaning of the silencer and follow the instructions for getting rid of urea deposits.
  10. Run Exhaust gas aftertreatment, checking for and getting rid of urea deposits.
  11. This wizard burns off any urea deposits in the mixing chamber.
  12. Check that the engine is getting the correct amount of air:
  13. Check charge air pressure sensor T122.
  14. Using measuring set 99 362, compare to ensure the charge air pressure sensor is measuring correctly.
  15. Check that charge air temperature sensor T121 is indicating a plausible value.
  16. Check that the engine is getting the correct amount of fuel, run Fuel leak test.
  17. Run Exhaust gas aftertreatment, function test SCR.
  18. If the NOx sensor still indicates a fault, change NOx sensor T115 downstream of the SCR catalytic converter.
  19. Verification Verify that the fault has been rectified by running Exhaust gas aftertreatment, function test SCR > select test stage > Check the NOx sensor.
  20. Check that the fault code has been deactivated.
  21. Proceed as follows to extinguish the emissions warning lamp:
  22. Turn the starter key to the locking position.
  23. Wait until the button for the hazard warning signal has been extinguished.
  24. Turn the starter key to drive position.
  25. Check that the fault code has been deactivated.
  26. Turn the starter key between the locking and drive positions 3 times.
  27. Wait until the hazard warning signal button has been extinguished between each turn.
  28. The emissions warning lamp should then be extinguished.
  29. Clear the fault code.
  30. Check the NOx sensors and ensure that the NOx sensors upstream and downstream of the SCR catalytic converter have not been mixed up.
  31. Check EMS fault codes related to charge air pressure and fuel.
  32. Check the reductant circuit:
  33. Check that the reductant doser is metering the correct volume of reductant, run Exhaust gas aftertreatment, troubleshooting the liquid components of the SCR system > Metering test.
  34. Check that the reductant doser is not leaking reductant into the silencer; run Leak test for reductant doser.
  35. Visually check whether the mixing chamber for the reductant is blocked or damaged by urea deposits.
  36. Run Visual check of urea deposits.
  37. If there is a blockage in the mixing chamber:
  38. Run Internal cleaning of the silencer and follow the instructions for getting rid of urea deposits.
  39. Run Exhaust gas aftertreatment, checking for and getting rid of urea deposits.
  40. This wizard burns off any urea deposits in the mixing chamber.
  41. Check that the engine is getting the correct amount of air:
  42. Check charge air pressure sensor T122.
  43. Using measuring set 99 362, compare to ensure the charge air pressure sensor is measuring correctly.
  44. Check that charge air temperature sensor T121 is indicating a plausible value.
  45. Run Functions > Check > Powertrain > Engine > EGR system > Exhaust gas aftertreatment, function test EGR and check the mass flow adaptation in the chart with the 12 bars.
  46. If the values deviate, follow the instructions and run Leak testing the EGR circuit.
  47. Check that the engine is getting the correct amount of fuel, run Fuel leak test.
  48. Run Exhaust gas aftertreatment, function test SCR.
  49. If the NOx sensor still indicates a fault, change NOx sensor T115 downstream of the SCR catalytic converter.
  50. Verification Verify that the fault has been rectified by running Exhaust gas aftertreatment, function test SCR > Select test stage > Check the NOx sensor.
  51. Check that the fault code has been deactivated and clear the fault code.
  52. Check the NOx sensors and ensure that they have not been mixed up.
  53. Check for other fault codes related to the engine or exhaust gas aftertreatment management system, and if so start with them.
  54. Check that the reductant doser is metering the correct amount of reductant.
  55. Run Exhaust gas aftertreatment, troubleshooting the liquid components of the SCR system > Metering test.
  56. Check that the reductant doser is not leaking reductant into the silencer.
  57. Run Leak test for reductant doser.
  58. Visually check whether the mixing chamber for the reductant is blocked or damaged by urea deposits.
  59. Run Visual check of urea deposits.
  60. If there is a blockage in the mixing chamber:
  61. Run Internal cleaning of the silencer and follow the instructions for getting rid of urea deposits.
  62. Run Exhaust gas aftertreatment, checking for and getting rid of urea deposits.
  63. This wizard burns off any urea deposits in the mixing chamber.
  64. Check that the engine is getting the correct amount of air:
  65. Check air pressure sensor T122/T47.
  66. Using measuring set 99 362, compare to ensure the charge air pressure sensor is measuring correctly.
  67. Check that charge air temperature sensor T121 is indicating a plausible value.
  68. Verification Verify that the fault has been rectified by running Exhaust gas aftertreatment, SCR function test.
  69. Select test stage Check the NOx sensor.
  70. Check that the fault code has been deactivated and clear the fault code. |
  71. Check that the NOx sensor is correctly fitted.
  72. Check EMS fault codes related to charge air pressure and fuel.
  73. Check the reductant circuit:
  74. Check that the reductant doser is metering the correct volume of reductant; run Exhaust gas aftertreatment, troubleshooting the liquid components of the SCR system > Metering test.
  75. Check that the reductant doser is not leaking reductant into the silencer; run Leak test for reductant doser.
  76. Visually check whether the mixing chamber for the reductant is blocked or damaged by urea deposits.
  77. Run Visual check of urea deposits.
  78. If there is a blockage in the mixing chamber:
  79. Run Internal cleaning of the silencer and follow the instructions for rectifying urea deposits.
  80. Run Exhaust gas aftertreatment, checking and rectification of urea deposit.
  81. This wizard burns off any urea deposits in the mixing chamber.
  82. Check that the engine is getting the correct amount of air:
  83. Check air pressure sensor T122.
  84. Using measuring set 99 362, compare to ensure the charge air pressure sensor is measuring correctly.
  85. Check that the charge air temperature sensor T121 is indicating a plausible value.
  86. Check that the engine is getting the correct amount of fuel; run Fuel leak test.
  87. Run Exhaust gas aftertreatment, SCR function test.
  88. If the NOx sensor still indicates a fault, renew NOx sensor T115 downstream of the SCR catalytic converter.
  89. Verification Verify that the fault is rectified by running Exhaust gas aftertreatment, function test SCR > select test stage > Checking the NOx sensor.
  90. Check that the fault code has been deactivated.
  91. Proceed as follows to extinguish the emissions warning lamp.
  92. Turn the starter key to the locking position.
  93. Wait until the button for the hazard warning signal has been extinguished.
  94. Turn the starter key to the drive position.
  95. Check that the fault code has been deactivated.
  96. Turn the starter key to the drive position and then back to the locking position 3 times.
  97. Wait until the button for the hazard warning signal has extinguished between each turn.
  98. The emissions warning lamp should then be extinguished.
  99. Clear the fault code. |
  100. Check the NOx sensors and ensure that the NOx sensors upstream and downstream of the SCR catalytic converter have not been mixed up.
  101. Check EMS fault codes related to charge air pressure and fuel.
  102. Check the reductant circuit:
  103. Check that the reductant doser is metering the correct volume of reductant, run Exhaust gas aftertreatment, troubleshooting the liquid components of the SCR system > Metering test.
  104. Check that the reductant doser is not leaking reductant into the silencer; run Leak test for reductant doser.
  105. Visually check whether the mixing chamber for the reductant is blocked or damaged by urea deposits.
  106. Run Visual check of urea deposits.
  107. If there is a blockage in the mixing chamber:
  108. Run Internal cleaning of the silencer and follow the instructions for getting rid of urea deposits.
  109. Run Exhaust gas aftertreatment, checking for and getting rid of urea deposits.
  110. This wizard burns off any urea deposits in the mixing chamber.
  111. Check that the engine is getting the correct amount of air:
  112. Check charge air pressure sensor T122.
  113. Using measuring set 99 362, compare to ensure the charge air pressure sensor is measuring correctly.
  114. Check that charge air temperature sensor T121 is indicating a plausible value.
  115. Run Functions > Check > Powertrain > Engine > EGR system > Exhaust gas aftertreatment, function test EGR and check the mass flow adaptation in the chart with the 12 bars.
  116. If the values deviate, follow the instructions and run Leak testing the EGR circuit.
  117. Check that the engine is getting the correct amount of fuel, run Fuel leak test.
  118. Run Exhaust gas aftertreatment, function test SCR.
  119. If the NOx sensor still indicates a fault, change NOx sensor T115 downstream of the SCR catalytic converter.
  120. Verification Verify that the fault has been rectified by running Exhaust gas aftertreatment, function test SCR > Select test stage > Check the NOx sensor.
  121. Check that the fault code has been deactivated and clear the fault code. |
  122. Check the NOx sensors and ensure that they have not been confused.
  123. Check for other fault codes related to the engine or exhaust gas aftertreatment system and in that case start with them.
  124. Check that the reductant doser is metering the correct amount of reductant.
  125. Run Exhaust gas aftertreatment, troubleshooting the liquid components of the SCR system > Metering test.
  126. Check that the reductant doser is not leaking reductant into the silencer.
  127. Run Leak test for reductant doser.
  128. Visually check whether the mixing chamber for the reductant is blocked or damaged by urea deposits.
  129. Run Visual check of urea deposits.
  130. If there is a blockage in the mixing chamber:
  131. Run Internal cleaning of the silencer and follow the instructions for rectifying urea deposits.
  132. Run Exhaust gas aftertreatment, checking and rectification of urea deposit.
  133. This wizard burns off any urea deposits in the mixing chamber.
  134. Check that the engine is getting the correct amount of air:
  135. Check air pressure sensor T122/T47.
  136. Using measuring set 99 362, compare to ensure the charge air pressure sensor is measuring correctly.
  137. Check that the charge air temperature sensor T121 is indicating a plausible value.
  138. Verification Verify that the fault is rectified by running Exhaust gas aftertreatment, function test SCR.
  139. Select test stage Checking the NOx sensor.
  140. Check that the fault code has been deactivated and clear the fault code.

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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