DTC A095: Stoplamp Switch Circuit Open

STOPLAMP SWITCH CIRCUIT OPEN





Diagnosis
This test checks for an open in the stoplamp circuit that prevents the stoplamp input to the electronic brake control module (EBCM) from changing states when the bake is applied. A fault exists if the voltage reading for the stoplamp switch is between 5.23 volts and 3.35 volts for 1 second.

Cause(s)
- There is an open in the stoplamp switch circuit.
- All the stoplamps are open.
- The ground path for all the stoplamps is open.
- There is a poor contact in the EBCM connector J1.
- The EBCM is faulty.

Fail Action
This DTC is used in conjunction with DTCs A091, and A092 to determine the cause of an open stoplamp switch fault. A "not open" circuit condition with no brake input may indicate a stoplamp contact, a fuse, or a mounting/ adjustment problem and is associated with DTC A091 and A092 failures. This fault identifies the cause as the monitor line, the lights (all bulbs open), the controller connection, or the controller interface circuit. The ABS is disabled and the ABS warning lamp is turned ON. A rehome is commanded to ensure that all motors are in the home position.

Test Description
The number(s) below refer to step(s) on the diagnostic table.
1. This step is used to confirm the existence of an open in the stoplamp switch circuitry.
2. This step indicates if the EBCM has received the stoplamp switch signal.
3. This step indicates the existence of an open circuit in the stoplamp switch or the stoplamp circuitry.
4. This step isolates the open circuit to either the stoplamp switch input circuitry or the EBCM.

Diagnostic Aids
An intermittent malfunction may be caused by a poor connection, wire insulation that has been rubbed through, or a wire that is broken inside the insulation.
Check the frequency of the malfunction by using the enhanced diagnostic feature of the scan tool as described in "Scan Tool Diagnostics." Scan Tool Diagnostics
Any circuitry that is suspected of causing the intermittent complaint should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wiring connections or physical damage to the wiring harness.





DTC A095 - Stoplamp Switch Circuit Open