P1633 FORD, LINCOLN, MERCURY: KEEP ALIVE POWER VOLTAGE TOO LOW
Description of DTC code P1633
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:
Battery cables or connectors may be faulty.
The Keep-Alive memory power supply circuit may have some damage to its electrical components.
The Powertrain Control Module may be in bad condition.
Possible solutions of the DTC code P1633
The steps to troubleshoot DTC P1633 OBDII, try this:
Consult the Technical Service Bulletins.
Check the battery terminals and cables for corrosion or poor connections. Make any necessary corrections.
Measure the voltage between the Keep Alive Memory circuit and the PCM. To do this, unplug the PCM. If the value obtained is less than 10.5 volts, you should check for damage to the wires that would cause an open circuit. Repair as required.
If there are no electrical inconsistencies, it engages the PCM and starts the engine until it reaches operating temperature. Then, run a self-test and retrieve the continuous memory fault codes. If P1633 is still present, there are probably problems with the PCM. Otherwise, run the diagnostics to other set codes.