Message Systems

U0022 CAN B BUS (+) CIRCUIT LOW





For a complete wiring diagram consult Diagrams/Electrical.


- When Monitored:
With the ignition switch on.

- Set Condition:
The Multi-Purpose Module (Police And Taxi Interface Module-PTIM) has detected the (W527) VSIM CAN B Bus (+) circuit is below a calibrated value.








Diagnostic Test


1. CHECK FOR ACTIVE DTC
With the scan tool, read the active DTCs.
Erase the DTCs.
Turn the ignition off, wait 10 seconds, then turn the ignition on.
With the scan tool, read the active DTC's.
Does the scan tool display this DTC as active?

Yes


- Go To 2


No


- If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals, and repair any obvious problems.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.




2. CHECK (W527) VSIM CAN B BUS (+) CIRCUIT FOR A SHORT TO GROUND




Turn the ignition off.
Disconnect the Multi-Purpose Module (Police And Taxi Interface Module-PTIM) C2 harness connector.
Disconnect the Multi-Purpose Module (Police And Taxi Interface Module-PTIM) 24 way harness connector (aftermarket light/siren controller side).
Disconnect the scan tool from the DLC.
Measure the resistance between ground and the (W527) VSIM CAN B Bus (+) circuit.
Is the resistance below 5.0 ohms?

Yes


- Repair the (W527) VSIM CAN B Bus (+) circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.


No


- Inspect the wiring and connectors for damage or shorted circuits. If ok, replace the Multi-Purpose Module (Police And Taxi Interface Module-PTIM).
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.