CAN Bus Termination Resistance Test

CAN BUS TERMINATION RESISTANCE TEST






RECORD BUS TERMINATION RESISTANCE
The following calculations show approximate values for bus termination. These calculations only apply to a CAN-C or CAN-Interior Bus. The lowest value is for a bus with the most non-dominant modules. The values shown represent dominant nodes at 61.9 Ohms (1% tolerance value) which more closely represents actual conditions.
















1. By measuring the resistance of a data bus (with the battery disconnected) a determination can be made as to the number of modules connected to that bus.
- With the battery disconnected obtain a measurement of the vehicles data bus termination resistance from any accessible harness connection point where bus circuits are present. Measure from bus (+) to bus (-).
- Compare this value to the table above.
- Identify the closest match.
- The column will indicate the number of non-dominant modules on the portion of bus measured.
- The row will indicate the number of dominant modules connected to the portion of bus measured.

2. The value given for "One-Dominant" would be representative of a portion of a bus split in the middle or one having an open somewhere between dominant modules. When a data bus is inoperative due to an open circuit somewhere in the data bus, a measurement of resistance and the above table could help identify the location of the problem.