Possible Causes:
* Faulty Wheel Speed Sensor (WSS): This is the most common cause. The WSS measures the speed of each wheel, and if one is faulty, the ABS and traction control systems can't function properly. A bad sensor sends incorrect or no data to the ABS module. Dirt, corrosion, or physical damage to the sensor or its wiring are common culprits.
* ABS Module Failure: The ABS module is the "brain" of the system. If it's malfunctioning, it can cause both lights to illuminate. This is a more expensive repair, often requiring replacement.
* Low Brake Fluid: While less likely to cause both lights, extremely low brake fluid can trigger warnings. Check your brake fluid level in the reservoir.
* Faulty ABS Control Unit: Similar to the module, a fault here can disable both systems.
* Wiring Issues: Damaged, corroded, or loose wiring in the ABS system can interrupt signals and cause the lights to stay on. This often involves the wiring harness to the wheel speed sensors.
* Brake Pressure Sensor: A faulty brake pressure sensor can send inaccurate readings to the ABS system, resulting in the warning lights.
Troubleshooting Steps:
1. Check Brake Fluid Level: Start with the simplest check. Low brake fluid indicates a leak somewhere in the braking system, which needs immediate attention.
2. Visual Inspection: Look for any obvious damage to wiring near the wheels or under the vehicle. Pay close attention to the wiring harness running to each wheel speed sensor.
3. Have the Codes Read: The most important step is to have the diagnostic trouble codes (DTCs) read from the vehicle's computer. An auto parts store often offers this service for free. The codes will pinpoint the specific problem. This is crucial because guessing can lead to unnecessary parts replacements.
4. Wheel Speed Sensor Check (if DTC points to one): Once you have the codes, if they point to a specific wheel speed sensor, you can (with some mechanical aptitude) test the sensor's output with a multimeter to see if it's providing a proper signal. Replacement is relatively inexpensive.
Important Considerations:
* Safety: While the car is drivable, the ABS and traction control are disabled. This reduces your braking performance and control, especially in slippery conditions. Drive cautiously and get the problem repaired as soon as possible.
* Professional Diagnosis: If you're not comfortable with automotive diagnostics, take your Aztek to a qualified mechanic for diagnosis and repair. Improper repair could lead to more serious problems.
Don't delay addressing this issue. Driving with these lights on means compromised safety. Getting the diagnostic codes read is the most effective first step.
