Component Location
General Description
VSM(Vehicle Stability Management) system is a safty system to reduce damage by using ESP, PSB(Pre-safe Seat Belt), SCC, Cluster under condition of a collision predicted. VSM control mecanism is as follows.
1. Preceding vehicle approaching : Cluster turns on yellow warning lamp.
2. Preceding vehicle approaching too close : ESP prepares breaking and PSB vibrates belt, Cluster turns on red warning lamp to inform danger to driver.
3. Under condition of a collision predicted : PSB retracts seat belt fully, ESP slows down the car and assist driver to make a proper break force according to situation.
DTC Description
SCC sets this code when the messages(TCU2) from TCM was not received within the last 500msec or improper message, checksum detected. System recovers to normal state if the message is received again.
DTC Detecting Condition
Item | Detecting Condition | Possible cause |
DTC Strategy | CAN message monitoring
| Open or poor connection in between TCM and SCC
Faulty TCM
|
Enable Conditions | Engine Run (engine rpm higher than 400 at least for 2s)
|
Threshold value | The messages(TCU2) from ECM was not received within the last 500msec
Improper messages(TCU2) detected
Improper checksum detected
|
Diagnosis Time | 500ms
|
Recover Condition | As soon as the message is received again
|
Fail Safe | VSM2 Red warning lamp turns on, VSM2 function permanently not available
|
Diagnostic Circuit Diagram
Signal Waveform & Data
Monitoring CAN HIGH and LOW simultaneously is important in monitoring CAN communication waveform. When CAN HIGH signal rise to 3.5V and LOW signal drops to 1.5V - voltage difference between HIGH and LOW signal is 2V - at BUS IDLE state(DIGITAL "1") whose reference voltage is 2.5V, "0" is recognized. Besides, comparing HIGH and LOW signal if opposite waveform is detected with the reference voltage of 2.5V, Check if current cam signal transfers correctly. Continuous "0"signal above 6BIT means the occurence of error in CAN communication. 1BIT is easily distinguished as calculating the time when "SOF"(START OF FRAME) which notifies the start of frame occurs. Check if "0"signal above 6BIT is detected continuously when monitoring CAN communication waveform.