Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code A042: Low Brake Pressure Circuit Open
When low pressure switch in the accumulator is closed, pressure is more than 1800 psi (127 kg/cm2 ), the anti-lock brake controller senses ground at the low brake pressure input. If low pressure switch is open, pressure less than 1800 psi (127 kg/cm2 ), the lamp driver module loses ground at terminal "C". The lamp drive module activates BRAKE warning indicator light and directs voltage to the low brake pressure input. If anti-lock brake controller does not sense ground or voltage at low brake pressure input, Code A042 will set.
- If BRAKE warning indicator light is on, an open exists in circuit No. 154 between lamp driver module and splice S245.
- Verifies open condition exists.
- Isolate open in circuit No. 154 between splice S245 and anti-lock brake controller.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.