Code p1633 2005 Ford Explorer XLT

2005 Ford Explorer

Engine will just die

This vehicle runs well and has plenty of power, but occasionally the engine will just die. It can happen at 10 mph or 60 mph. It will crank back up and run. Appears to be an intermittent problem. Pulled two codes from the computer:
P1633 KAM (Keep Alive Memory) Voltage Too Low
P0462 Fuel Level Sensor Low Input

I don’t know that these codes have anything to do with the problem we’re having with the vehicle. I’ve checked some of the simple stuff like making sure there is plenty of fuel in the tank, and I checked the battery voltage (a good 12.6 volts).

What do you think?


I wouldn’t think that these codes have anything to do with the engine intermittently dying on you. Unfortunately this is one of the most difficult problems to diagnose. If the engine wouldn’t restart it would be as simple as just figuring out if it isn’t getting fuel or spark. But since it starts right back up it make it that much more difficult. I would guess a loose connection or a failing sensor. As for which one, difficult to tell. Unfortunately in this case it would be more cost effective to let the problem get worse in order to know exactly what to repair/replace. No need to through parts at it if you don’t have to.

What does code P1633 mean?

P1633 means that the powertrain control module (PCM) has detected low voltage on the keep alive memory circuit. This is the circuit that supplies constant battery voltage to the keep alive memory portion of the PCM so it can retain information regarding fuel control, idle control and transmission control adaptive strategies to name a few. If the battery is disconnected or voltage drops below 10.5 volts this code will be set. If the battery has not been disconnected then the circuit will need to be checked for opens or high resistance in the wire, shorts, blown fuse, high voltage r/f interference from ignition or charging system components, or the PCM being being faulty itself.

Ford Code P1633

KAM Volt Low

Code P1633 Probable Causes

  1. Sensor or solenoid faulty
  2. Connector terminal contact is damaged or corroded
  3. Wire harness – Check harness for correct voltage, open, short to ground or short to voltage
  4. Update control unit software – Check for the latest control unit update
  5. Powertrain or Engine Control Module faulty
  6. Battery voltage low

Ford Code P0462

Fuel level sensor A circuit low input

Code P0462 Probable Causes

  1. Sensor or solenoid faulty
  2. Connector terminal contact is damaged or corroded
  3. Wire harness – Check harness for correct voltage, open, short to ground or short to voltage
  4. Update control unit software – Check for the latest control unit update
  5. Powertrain or Engine Control Module faulty
  6. Battery voltage low

Sources: Justanswer, Chilton