Incorrect Reading On Deceleration

If there is no voltage, check EGR control switch. With speed sensor jumped and engine at idle, remove vacuum hose at EGR control switch and check for vacuum at control switch.
If vacuum is available, reconnect hose and check for voltage at EGR control solenoid valve A. If there is no voltage, replace EGR control switch and retest.

Fig 1: Accord Exhaust Gas Recirculation System
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Civic Exhaust Gas Recirculation System
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Prelude Exhaust Gas Recirculation System
Courtesy of AMERICAN HONDA MOTOR CO., INC.