Normal Operation
The Smart Junction Box (SJB) controls the output of several vehicle systems by means of solid state drivers. When an overload occurs on any of these drivers, a DTC is set. The module tracks the number of repetitive faults on each of these circuits and compares this number of overloads to 3 progressive thresholds established for each circuit. If the 3 thresholds have not been exceeded, then the DTC for the affected circuit can be cleared by eliminating the fault, then clearing the DTCs and running a self-test.
At the point that each of the first 2 thresholds are exceeded, DTC B106E is set along with the DTC relating to the affected circuit. Once the final (third) threshold is exceeded, the affected output is permanently disabled, and DTC B106F is set along with DTC B1342, at which time the SJB must be replaced.
- DTC B106E (Solid State Driver Disabled Due to Short Circuit) - sets when the SJB has disabled a circuit due to a repetitive fault causing a circuit overload. A corresponding DTC for the circuit in question is also set.
- DTC B106F (Module Disabled Due to External Fault) - sets when one or more output functions are permanently disabled due to a repetitive circuit overload fault. DTC B106F is set with DTC B106E. When DTC B106F is present, a new SJB must be installed after the fault condition has been corrected.
This pinpoint test is intended to diagnose the following:
- Output circuit short to ground or voltage
- SJB