Q: Service suspension system is on

If the suspension warning light is illuminated that means that trouble codes have been stored. Those codes should be downloaded by a mechanic and evaluated to determine the cause of the fault. Once the fault is pinpointed, necessary repairs are made and that could involve anything from fixing a loose wire to replacing a bad sensor. In all events, the issue is definitely resolvable if you request a suspension warning light diagnostic.

With regard to the vibration on braking, such vibration is typically due to excessive thickness variation in the brake rotor, brake pad defects, or excessive rotor runout as installed on the wheel hub. Suspension faults are possible, too. If the brake rotors that were installed on your car are new and are OEM (dealer supplied), thickness variation in the rotor is not generally an issue but you still could have vibration due to excessive run-out as the rotor sits on the wheel hub. As installed on the wheel hub, rotor run-out should be measured by the mechanic using a specialized dial indicator and verified to be LESS than .002 inches. If installed rotor run-out exceeds .002 inches, the run-out MUST be corrected by shimming or re-indexing the rotor to the hub. To have the root cause of the brake vibration identified, please request a brake and suspension system diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.