Monitor DTC Status
- Connect scan tool to Data Link Connector (DLC).
- Ignition "ON" & engine "OFF".
- Select "Diagnostic Trouble Codes (DTC s)" mode and monitor "DTC Status" parameter.
- Is the DTC B1646 present?
DTC B1646 doesn't show up by itself. It means that there's any fault in
- Multifunction switch signal (light, wiper)
- CAN Communication line
- FAM, RAM
so, B1646 show up with DTC B1603, B1611, B1612, B1950 and if these problems are solved, it disappear automatically.
YES
Go to COMPONENT INSPECTION procedure.
NO
Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.