On-board diagnostics 2 or OBD2
In my previous post i have explained what is ODB? OBD is nothing but it helps the owner and technician to find out the what is problem in vehicle.OBD2 is the advance version of OBD1, OBD-II is the protocol used by all cars built after 1996
In OBD2 lot of improvement is done compared to OBD1 ,improvement is like standardization,signaling,diagnostics protocols ect.
OBD 2 connector are standardized:
In OBD 1 Each manufacturer used their own diagnostic link connector (DLC), DLC location, DTC definitions, and procedure to read the DTCs from the vehicle. DTCs from OBD-I cars are often read through the blinking patterns of the 'Check Engine Light' (CEL) or 'Service Engine Soon' (SES) light. By connecting certain pins of the diagnostic connector, the 'Check Engine' light will blink out a two-digit number that corresponds to a specific error condition.
 |
| OBD1 |
but OBD2 connector is stanardized all the manufacturer using the same connector .We an use any ODB2 scaning tool to scan the CAR.
 |
| OBD2 |
OBD 2 Signal standardization:
SAE J1850
ISO 14230 KWP2000
 |
ISO 14230 KWP2000 |
ISO 15765 CAN
 |
ISO 15765 CAN |
Standardization on OBD2 protocol:
UDS unified diagnostic service(CAN-BUS)
- ISO 15765-4 CAN (11 bit ID,500 Kbaud)
- ISO 15765-4 CAN (29 bit ID,500 Kbaud)
- ISO 15765-4 CAN (11 bit ID,250 Kbaud)
- ISO 15765-4 CAN (29 bit ID,250 Kbaud)
