Testing With The MOPAR® Diagnostic Splice Block Kit

The splice block connector numbers, locations, CAN Bus circuits, and CAN Bus network flow (To BUS and From BUS) MUST be determined before proceeding with diagnosing the CAN Bus network. To help determine the flow of the CAN Bus network, use the Wiring Diagrams, Component Views, Connector End Views and corresponding test cables with wiring application charts in the Mopar® (special tool #2028700081, Kit, Diagnostic Splice Block).

Courtesy of CHRYSLER GROUP, LLC

NOTE: Individually opening and closing the From BUS, To BUS, and Node switches, while also monitoring the scan tool topology screen and noting which communication DTCs set, can help determine the direction of the fault on the CAN Bus. For best results, allow the network and scan tool to update before opening or closing additional switches.

NOTE: The Test High and Low ports on the Breakout Box, Splice Block 24-Way 2028701081 are equivalent to the CAN Bus (+) and (-) circuits of the network that it is connected to and can be used to take CAN Bus measurements.

NOTE:

Resistance of a CAN Bus network must be measured with the 12-volt Main Battery, and Auxiliary Battery (if equipped), disconnected.

Determine the To BUS and From BUS flow of the CAN Bus network:

Due to various vehicle options, the VIN MUST be entered in the Wiring Diagrams to display the most accurate splice block connector and CAN Bus circuit information.
With the ignition ON, view the scan tool topology screen and note any ECUs in Red.
Using the Wiring Diagrams, locate the splice block connector closest to the ECU(s) in Red and where the tool will be connected.
Using the Connector End Views in Wiring Diagrams, match the CAN Bus connector terminals with the above SPLICE BLOCK WIRING CHART to determine the To BUS and From BUS flow of the CAN Bus network.

NOTE: Opening and Closing the Node 1-6 switches while measuring the CAN Bus voltages and resistances, along with using the Wiring Diagrams and the above SPLICE BLOCK BREAKOUT BOX WIRING CHART, can help determine if a module or CAN Bus circuit, within the testing location splice block connector, is the cause of the CAN Bus fault.

Measure and record the voltage and resistance values of CAN Bus circuits:

Determine the To BUS and From BUS flow of the CAN Bus network before proceeding. Perform the above steps, if needed.
Make sure all of the switches on the (special tool #2028701081, Breakout Box, Splice Block 24-Way) are in the closed position before proceeding.
With the ignition OFF, connect the (special tool #2028701081, Breakout Box, Splice Block 24-Way) to the splice block connector that was determined where the testing will occur.
With the ignition ON, and using a DVOM, measure and record the
voltage

on the

To BUS

CAN Bus (+) and (-) circuits.
- Connect the (-) lead to a known good chassis ground and the (+) lead to the Test High port.
- Connect the (-) lead to a known good chassis ground and the (+) lead to the Test Low port.
With the ignition ON, and using a DVOM, measure and record the
voltage

on the

From BUS

CAN Bus (+) and (-) circuits.
- Connect the (-) lead to a known good chassis ground and the (+) lead to the Test High port.
- Connect the (-) lead to a known good chassis ground and the (+) lead to the Test Low port.
With the Main Battery and Auxiliary Battery (if equipped) disconnected, measure and record the
resistance

on the

To BUS

CAN Bus (+) and (-) circuits.
- Connect the (-) lead to the Test Low port and the (+) lead to the Test High port.
With the Main Battery and Auxiliary Battery (if equipped) disconnected, measure and record the
resistance

on the

From BUS

CAN Bus (+) and (-) circuits.
- Connect the (-) lead to the Test Low port and the (+) lead to the Test High port.
Compare the recorded CAN Bus voltage and resistance measurements with the above CAN BUS VOLTAGES table and the CAN BUS TERMINATION RESISTOR RESISTANCES table. Perform the appropriate repair.