Scania BMU DTC 626 Discharging the propulsion battery E83

BMU Battery Management Unit · Scania · 2 variants

Code 626 (decimal). Some diagnostic tools show it in hexadecimal as 0272.

In short

The current state of charge of the propulsion battery is below the permitted level. The limit value is 8% for the PGRT series and 5% for the PGRS series.

Variant 1

Applies to: BMU6 (RES)BMU6 (RESXA)BMU6 (RESXB)BMU6 (RESXC)BMU6 (RESXD)BMU6 (RESXE)BMU6 (RESXF)BMU6 (RESXG)BMU6 (RESXH)BMU6 (RESXI)BMU6 (RESXJ)BMU6 (RESXK)

What does Scania BMU fault code 626 mean?

The current state of charge of the propulsion battery is below the permitted level. The limit value is 8% for the PGRT series and 5% for the PGRS series.

What causes Scania DTC 626?

The vehicle has been parked for a longer period of time and the propulsion battery is discharged. The battery has not had time to carry out cell balancing. Stand-by current on the cable harness for voltage class B discharges the propulsion battery. A component with voltage class B is active and using energy.

How does the system react?

Yellow warning indication of an electric drive system fault is displayed.

What are the symptoms?

If the vehicle has multiple propulsion batteries: - The contactors cannot be closed on the relevant propulsion battery. - The vehicle's total battery capacity and range are reduced. If the vehicle has only one propulsion battery: - VOR. - Electric drive of the vehicle is not possible. - The vehicle's 24 V voltage is turned off. - No charge is possible.

How to fix Scania BMU fault code 626?

  1. Start the vehicle if it has been parked for a longer period and the state of charge is between 10 and 15%.
  2. The propulsion battery is then charged automatically to the normal state of charge.
  3. Charge the propulsion battery manually if the state of charge is below 10%.
  4. Start the vehicle and then start the battery charging wizard.
  5. Park the vehicle with the 15 voltage switched off for 12 hours if the vehicle has been driven hard during the last week.
  6. The propulsion battery can then carry out cell balancing.
  7. Cell balancing is carried out automatically by the propulsion battery.
  8. Test drive the vehicle.
  9. Accelerate hard to > 60 km/h and then brake slowly until the vehicle is stationary.
  10. Repeat this several times during the test drive.
  11. Make sure that the propulsion battery is fully charged several times during the test drive.
  12. Park the vehicle for at least 30 mins and read the state of charge.
  13. The value should be above 25%.
  14. Check whether the fault code has been generated again.
  15. Carry out cell balancing once more if the fault code has been generated again.
  16. Check whether GMS has generated any fault codes concerning plausibility checks.
  17. Make sure there is no fault code concerning insulation.
  18. Check that the propulsion battery temperature is above 10°C so that a heating request is not active.
  19. Read the signal for current in the propulsion battery.
  20. The value should be close to 0 when only 15 voltage is switched on.
  21. Start the engine.
  22. Read the current level in the propulsion battery and direct current converter E84 (DCC) and the torque for inverter E82 (MGU).
  23. The value for the propulsion battery and the direct current converter should be as close to each other as possible, and the inverter torque should be close to 0.
  24. Switch off the system and disconnect the heater fuse.
  25. Carry out the following steps if the value for the propulsion battery and the direct current converter differ too much:
  26. Switch on the system again and check whether the value for the propulsion battery and the direct current converter are the same.
  27. Renew the heater if the values are the same.
  28. Renew propulsion battery.
  29. When renewing the propulsion battery, carry out a Synchronisation of propulsion battery information.

Variant 2

Applies to: BMU5

Detection

The current state of charge of the propulsion battery is below the permitted level. The limit value is 8% for the PGRT series and 5% for the PGRS series.

Possible cause

The vehicle has been parked for a longer period of time and the propulsion battery is discharged. The battery has not had time to carry out cell balancing. Stand-by current on the cable harness for voltage class B discharges the propulsion battery. A component with voltage class B is active and using energy.

System reaction

Yellow warning indication of an electric drive system fault is displayed.

Symptoms

If the vehicle has multiple propulsion batteries: - The contactors cannot be closed on the relevant propulsion battery. - The vehicle's total battery capacity and range are reduced. If the vehicle has only one propulsion battery: - VOR. - Electric drive of the vehicle is not possible. - The vehicle's 24 V voltage is turned off. - No charge is possible.

How to fix

  1. Start the vehicle if it has been parked for a longer period and the state of charge is between 10 and 15%.
  2. The propulsion battery is then charged automatically to the normal state of charge.
  3. Charge the propulsion battery manually if the state of charge is below 10%.
  4. Start the vehicle and then start the battery charging wizard.
  5. Park the vehicle with the 15 voltage switched off for 12 hours if the vehicle has been driven hard during the last week.
  6. The propulsion battery can then carry out cell balancing.
  7. Cell balancing is carried out automatically by the propulsion battery.
  8. Test drive the vehicle.
  9. Accelerate hard to > 60 km/h and then brake slowly until the vehicle is stationary.
  10. Repeat this several times during the test drive.
  11. Make sure that the propulsion battery is fully charged several times during the test drive.
  12. Park the vehicle for at least 30 mins and read the state of charge.
  13. The value should be above 25%.
  14. Check whether the fault code has been generated again.
  15. Carry out cell balancing once more if the fault code has been generated again.
  16. Check whether GMS has generated any fault codes concerning plausibility checks.
  17. Make sure there is no fault code concerning insulation.
  18. Check that the propulsion battery temperature is above 10°C so that a heating request is not active.
  19. Read the signal for current in the propulsion battery.
  20. The value should be close to 0 when only 15 voltage is switched on.
  21. Start the engine.
  22. Read the current level in the propulsion battery and direct current converter E84 (DCC) and the torque for inverter E82 (MGU).
  23. The value for the propulsion battery and the direct current converter should be as close to each other as possible, and the inverter torque should be close to 0.
  24. Switch off the system and disconnect the heater fuse.
  25. Carry out the following steps if the value for the propulsion battery and the direct current converter differ too much:
  26. Switch on the system again and check whether the value for the propulsion battery and the direct current converter are the same.
  27. Renew the heater if the values are the same.
  28. Renew propulsion battery.
  29. When renewing the propulsion battery, carry out a Calibration of propulsion battery information.

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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