Can Bus Instrument Cluster To Data Bus OBD Interface, Checking: Function
The Engine Control Module - J623 - communicates with other CAN-Bus capable control modules.
The control modules are connected by two data bus wires which are twisted together (CAN_High and CAN_Low), and exchange information (messages). Missing information on the CAN-bus is recognized as a malfunction by the Engine Control Module - J623 - and the other control modules connected to the CAN-bus.
Trouble-free operation of the CAN-Bus requires that it have a terminal resistance. This central terminal resistance is located in the Engine Control Module - J623 -.
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK
Start diagnosis
-- Disconnect the Instrument Cluster Control Module -J285- electrical harness connector.
The Engine Control Module - J623 - must remain connected for the following step.
-- Using a multimeter, Check the Instrument Cluster Control Module -J285- electrical harness connector terminals T32/29 to T32/30 for resistance.
Specified value: 60 to 72 Ω (at approx. 20° C)
If the specified value was not obtained:
-- Check the wiring for a short circuit to Battery (+), or an open circuit.
-- Check the wiring connection for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
If no malfunction is found in the wiring:
-- Replace the Engine Control Module - J623 -. Refer to the appropriate service information.
If the specified value was obtained: