Front Area Module

B1646

Component Location:

General Description
When signal error occurs in BCM module, Rescue mode is activated for the safety or driver. System operating state is divided into Normal mode, Safe mode and Rescue mode. Normal mode indicates every modules are in good condition, Safe mode is the transitional mode between Normal and Rescue mode which prevents system jamming arised by intermittent abnormal signal. If error signal is inputted to BCM continuously in Safe mode, Rescue mode - the next mode - is activated. Rescue mode is classified into software Rescue mode which is applied when important CAN signal or hardware input is unavailable and hardware Rescue mode which is applied when hardware Watchdog toggle does not turn on. When system comes to be in normal operating condition, Rescue mode is deactivated then it returns to Normal mode.

DTC Description
The ECM sets DTC B1646 if Rescue mode is activated at FAM.

DTC Detecting Condition:

Monitor Scantool Data
1. Connect scantool to Data Link Connector (DLC).
2. Ignition "ON" & engine "OFF"
3. Select "Diagnostic Trouble Codes (DTCs)" mode and monitor "DTC Status" parameter
4. 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
a. Go to "Inspection & Repair" procedure

NO
a. 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.

Component Inspection

1. Connect scantool to Data Link Connector (DLC).
2. Ignition "ON" & engine "OFF"
3. Erase the DTC.
4. Is the DTC erased?

YES
a. Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace if necessary and then go to "Verification of Vehicle Repair" procedure.

NO
a. Refer to troubleshooting procedure of the DTC code which is set with this code.

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode and then clear DTC
2. Operate the vehicle and monitor the DTC on the scantool
3. Are any DTCs present?

YES
a. Go to the applicable troubleshooting procedure

NO
a. System is performing to specification at this time.