P1633 FORD, LINCOLN, MERCURY: KEEP ALIVE POWER VOLTAGE TOO LOW
POST UPDATED IN June, 2023
P1633 FORD, LINCOLN, MERCURY: KEEP ALIVE POWER VOLTAGE TOO LOW
The Keep-Alive Memory (KAM) is used for storing the various drive cycle data. It changes depending on the sensor inputs and driving inputs. When the car’s battery is unplugged, the memory is erased and the PCM (Powertrain Control Module) goes into standby mode. This controller uses the learned data for the right operation of the engine.
The OBDII fault code P1633 on Ford, Mercury, and Lincoln vehicles indicates that the PCM has found a voltage below 10.5V in the Keep-Alive Memory control circuit. This circuit delivers a constant voltage from the battery to keep the memory alive so that the PCM maintains the recording data.
Storage of the P1633 OBD2 diagnostic code P1633 occurs due to one of the following reasons:
The steps to troubleshoot DTC P1633 OBDII, try this: