Part 3
2 Monitoring Functions Contd...2.10 DC link over voltage hardware monitor (P0C79)
2.10.1 Monitoring strategy
In addition to the DC link voltage sensor a hardware module is used to protect the system against DC link over voltage. If an over voltage is detected the system will be restricted and a fault code is stored
2.10.2 Enable condition
No enable conditions necessary.
2.10.3 Chart(s) and flow chart(s)
2.11 DC link current sensor monitor
2.11.1 DC link current sensor short cuts (P0A53/P0A54)
2.11.1.1 Monitoring strategy
The DC link current sensor is checked by the output value. If the measured current value exceeds an upper or lower current threshold, a short cut to battery or short cut to ground is detected.
2.11.1.2 Enable condition
No enable condition necessary.
2.11.1.3 Chart(s) and flow chart(s)
2.11.2 DC link current sensor out of range (P0A52)
2.11.2.1 Monitoring strategy
If the system state is set to drive, this monitoring strategy will check the current value to exceed an upper current threshold.
2.11.2.2 Enable condition
System state: drive
2.11.2.3 Chart(s) and flow chart(s)
2.11.3 DC link current sensor offset monitor (P0A52)
2.11.3.1 Monitoring strategy
While system state is set to initialization, the DC current value is should be around zero. If the deviation of the current value exceeds its limit, a fault is detected.
2.11.3.2 Enable condition
System state: init
2.11.3.3 Chart(s) and flow chart(s)
2.12 DC link short cut monitor (P0A1B)
2.12.1 Monitoring strategy
This functionality calculates the internal resistance of the DC link part inside the drive motor controller. The resistance is calculated from DC link voltage and DC link current. If the resistance is too low, it will be detected as a short cut.
2.12.2 Enable condition
The DC link current has to be higher than a minimal threshold.
2.12.3 Chart(s) and flow chart(s)
2.13 DMCM performance monitor (P0A90)
2.13.1 DMCM efficiency check
2.13.1.1 Monitoring strategy
To evaluate the drive motor efficiency, this monitoring function compares the electrical with the mechanical power. The difference between both is calculated as factor of efficiency. If the calculated efficiency is too low, a malfunction is detected.
The electrical power will be calculated with DC link current and voltage, the mechanical power with rotor speed and the phase currents.
Depending on charging or discharging, the direction of efficiency calculation changes.
2.13.1.2 Enable condition
The electrical power has to exceed a minimum positive or negative threshold.
The drive motor speed has to be in a range.
2.13.1.3 Chart(s) and flow chart(s)
2.13.2 Excitation flux monitor
2.13.2.1 Monitoring strategy
This function is enabled while offset angle calibration. Within the freewheeling phase, after the flux calibration this monitor evaluates the excitation flux of the drive motor. If this flux exceeds an upper or low limit a malfunction is detected. These limits are depending on the drive motor temperature. If under any temperature condition a malfunction is detected, the fault code will be stored.
2.13.2.2 Enable condition
System state: offset angle calibration
2.13.2.3 Chart(s) and flow chart(s)
2.13.3 Current controller plausibility
2.13.3.1 Monitoring strategy
The internal current controller is needed to adjust the drive motor current to given set points. This control loop uses a field orientated coordinate reference system to define phase position and amplitude with two internal calculated voltage components. In addition a drive motor model also calculates these voltages. The monitor evaluates the deviation between controller output and model output. If the deviation is to high, the current controller out does not fit to the calculated drive motor voltage and a malfunction is detected.
2.13.3.2 Enable condition
No enable condition necessary
2.13.3.3 Chart(s) and flow chart(s)
2.14 Internal ECU malfunctions
2.14.1 Multiple power supply - 5 VDC, DC link current sensor - (P06B0/ P06B1/ P06B2, P0A1B)
2.14.1.1 Monitoring strategy
An internal hardware check is integrated within the sensor power supply device drives. If an internal malfunction is detected, a fault code will be stored.
2.14.1.2 Enable condition
No enable condition necessary.
2.14.2 IGBT module hardware monitor (P0A1B)
2.14.2.1 Monitoring strategy
An internal hardware check is integrated within the IGBT module.
If an internal malfunction is detected, a fault code will be stored.
2.14.2.2 Enable condition
No enable condition necessary.
2.14.3 AD converter (P060B)
2.14.3.1 Monitoring strategy
Within in the DMCM wake-up, an AD converter calibration is performed.
If the calibration can not be finished in a fixed time or if the needed time to convert a value is too long, a malfunction is detected and a fault code is stored.
2.14.3.2 Enable condition
System state: initialization
2.14.4 Internal processor check - Flip-flop (P0606)
2.14.4.1 Monitoring strategy
Continuous internal hardware check.
2.14.4.2 Enable condition
No enable condition necessary.
2.14.5 Coding monitor (P151A)
2.14.5.1 Monitoring strategy
It will be checked that the DMCM coding correspond to coding information via CAN.
2.14.5.2 Enable condition
CAN communication established
2.14.6 EEPROM checksum monitor (P062F)
2.14.6.1 Monitoring strategy
Continuous memory cell check.
2.14.6.2 Enable conditions
No enable condition necessary.
2.14.7 Internal failure detection (P0A1B)
2.14.7.1 Monitoring strategy
If an internal hardware malfunction is detected, a fault code will be stored.
2.14.7.2 Enable condition
No enable condition necessary.
2.15 CAN monitoring
2.15.1 CAN device driver, CAN-RAM (P0604)
2.15.1.1 Monitoring strategy
Check for internal CAN controller malfunctions while initialization.
2.15.1.2 Enable conditions
System state: initialization
2.15.2 Hybrid CAN controller
2.15.2.1 Monitoring strategy
Internal device check for:
- bus off (U0028)
- global timeout (U0029)
2.15.2.2 Enable conditions
No enable condition necessary.
2.15.3 Power train CAN controller
2.15.3.1 Monitoring strategy
Internal device check for:
- bus off (U0001)
- global timeout (U0002)
2.15.3.2 Enable conditions
No enable condition necessary.
2.15.4 Message monitoring
2.15.4.1 Battery energy control module, BECM (U0111/ U0412)
2.15.4.1.1 Monitoring strategy
All BECM messages will be monitored for:
- time out
- checksum
- signal length
- information content
2.15.4.1.2 Enable conditions
No enable condition necessary.
2.15.4.2 Engine control module, ECM (U0100/ U0401)
2.15.4.2.1 Monitoring strategy
All ECM messages will be monitored for:
- time out
- checksum
- signal length
- information content
2.15.4.2.2 Enable conditions
No enable condition necessary.
2.15.4.3 Traction control module, ESP (U0122/ U0416)
2.15.4.3.1 Monitoring strategy
All ESP messages will be monitored for:
- time out
- checksum
- signal length
- information content
2.15.4.3.2 Enable conditions
No enable condition necessary.
2.15.4.4 Gateway timeout (U0146)
2.15.4.4.1 Monitoring strategy
All ESP messages will be monitored for:
- time out
2.15.4.4.2 Enable conditions
No enable condition necessary.