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DTC 93

Fig. 57 Code 93, Brake Switch Circuit Open On Initialization:




Circuit Diagram:






BRAKE SWITCH CIRCUIT OPEN DURING INITIALIZATION
When the wheel speed sensors indicate to the ABS control module that the vehicle is under braking, the ABS control module should receive voltage from the brake switch. If no voltage is received, ABS is disabled and the antilock telltale will be turned On. Check for ABS code 95. If present, proceed to the code 95 diagnostic description.

CODE PARAMETERS
Code 93 sets if:
^ Brake switch circuit is open during initialization.
^ This code can only set if codes 91 or 92 failed on previous seven ignition cycles and no brake transition has been seen since.

DIAGNOSTIC AIDS
When attempting to diagnose an intermittent problem, use the Scan tool (select Malfunction History from Scan tool ABS menu) to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

Intermittents or opens suspected to be at the connectors can be detected by using a diagnostic service probe. Voltage can be read on wires without disconnecting any connectors.

Check the tightness of the female terminal grip with a spare male terminal.

The ABS system will initialize (run motors down then up) when the vehicle is driven at least 5 km/h (3 mph) after start-up.

NOTE: Initialization alternates between left front/rear and right front/rear each ignition cycle.

Brake switch is normally open. Depressing brake pedal completes (closes switch) the circuit.

Check brake switch adjustment.