The Obdii Code C0267 indicates an open circuit in the pump motor of the Anti-lock Braking System (ABS). This article explains the code’s meaning, causes, symptoms, and diagnostic steps.
The Electronic Brake Control Module (EBCM) controls the ABS pump motor by grounding the circuit. The EBCM monitors a feedback voltage signal from the pump motor. When off, the voltage is high. When winding down after operation, the voltage is low. This feedback loop allows the EBCM to determine proper motor function. A C0267 code signifies a break in this circuit.
Causes of C0267
Several factors can contribute to a C0267 code:
- Open or Shorted Pump Motor: Damage to the pump motor itself can disrupt the circuit, leading to an open circuit fault.
- Open or Shorted Pump Motor Driver Circuit: Wiring issues between the EBCM and the pump motor, such as breaks or shorts, can trigger the code.
- Seized Pump Motor: A seized motor prevents proper operation and can cause the open circuit fault.
- Damaged EBCM: In rare cases, a faulty EBCM can be the root cause.
Symptoms of C0267
Common symptoms associated with a C0267 code include:
- Illuminated ABS Warning Light: The ABS warning light on the dashboard will typically illuminate.
- Disabled ABS: The ABS system may be disabled, preventing it from functioning during hard braking.
- Diagnostic Trouble Codes (DTCs): A scan tool will reveal the C0267 code, along with potentially other related codes such as C0268 (Pump Motor Circuit Shorted).
Diagnosing C0267
Diagnosing a C0267 requires a systematic approach:
- Verify the Code: Use an OBDII scanner to confirm the presence of the C0267 code.
- Visual Inspection: Inspect all wiring and connectors associated with the ABS pump motor for damage, corrosion, or loose connections.
- Circuit Testing: Perform continuity and resistance tests on the pump motor circuit to identify any opens or shorts.
- Pump Motor Test: Use a scan tool to command the pump motor ON and OFF. Observe for proper operation and monitor feedback voltage.
- EBCM Test: If all other components check out, the EBCM itself may need testing.
Clearing the Code
After repairs are completed, clear the C0267 code using a scan tool. Driving the vehicle above 6 km/h (4 mph) may also help clear the code if the issue is resolved. Note that a shorted pump motor may damage the EBCM. Follow diagnostic procedures carefully to avoid further damage. Driving the vehicle is crucial for accurate diagnosis, as simulated tests with a scan tool might not replicate real-world conditions. Always consult a qualified mechanic if you are unsure about any diagnostic or repair procedures.
