Diagnostic Test
WARNING: This page is about a different car, the 2022 Chrysler Voyager and 2022 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.
TESTING LIN BUS USING THE MOPAR SCOPE
NOTE:
Some vehicles can have multiple LIN connections within a connector, make sure that you are testing the correct LIN circuit.
For a complete LIN BUS SYSTEM wiring diagram, refer to the appropriate system wiring diagram .
- Connect the black pin for each test lead to Chassis ground. Connect the blue lead to the LIN circuit to be tested.
- Start the Mopar Scope.
- Turn the ignition on.
- Operate the systems connected to the LIN bus being tested to observe signal changes. Move connectors and wiring to look for any signal drop-out.
- When connected to the vehicle harness correctly, the LED on the breakout box will light up to indicate that there is activity on the bus.
- A waveform should appear.
The image below is of a normal LIN bus waveform using the Mopar Scope.
DESCRIPTION MEASUREMENT CHANNEL A 20 volts TIME BASE 1 ms/div [milliseconds / division control] ZOOM / VIEW X1 - HORIZONTAL & VERTICAL NOTE:The Mopar Scope has preset Guided Tests for Communications testing of the LIN bus.
- The waveform should reveal that data is being exchanged continuously along the LIN bus and the peak voltages are correct.
- Determine the type of LIN waveform fault (short, open, etc.) the vehicle presently has.
Did the Mopar Scope show the LIN bus waveform fault?
- Use the appropriate SYSTEM WIRING DIAGRAMS as a guide to follow the path of the circuit(s) to isolate the fault further and then repair / replace as needed.
- The condition that originally caused the concern may not be present at this time.
- Continue to use the Mopar Scope and wiring diagrams as a guide to trace the circuits and look for any in-line connectors where the fault could occur intermittently by wiggling the wire harness and connectors.
- Look for any chafed, pierced, pinched, or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related wire harness connectors.
- Perform any Technical Service Bulletins (TSBs) that may apply.