Chart E3, Valve Chatter During Stops
WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 1990 Pontiac Bonneville, 1990 Oldsmobile Ninety-Eight, 1990 Oldsmobile Eighty-Eight, 1990 Cadillac Fleetwood, and 1990 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
- This chart is used to isolate the cause of valve cycling or chattering during normal stops. Symptoms include underhood chattering noise and/or pulsing at brake pedal. Common cause is erroneous wheel speed sensor signals.
- A weak wheel sensor signal can be interpreted by the EBCM as a locked wheel. At low speeds the signal becomes weak and the sensor indication causes the EBCM to engage the anti-lock mode. This could occur without setting codes.