Circuit Function
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
The powertrain control module (PCM) stores the vehicle operating conditions in random access memory (RAM) and utilizes this information to compensate for component variability. The keep-alive power (KAPWR) circuit supplies battery voltage (B+) to the PCM to maintain the memory contents when the ignition switch is off.
CAUTION:
The PCM harness connectors must be properly seated and the connector latch properly attached to eliminate possible driveability concerns or a no-start condition. Installing PCM connectors on an angle may cause an improper connection, misdiagnosis, and damaged components. Install the connector until the lever pivots and seats itself. Apply light pressure to get the connector into position on the PCM and then fully seat the connector.
NOTE:
Visually inspect the harness connectors for corrosion, damage, proper mating and correct pin tension.
NOTE:
When the PCM is disconnected additional DTCs will be set. Clear all DTCs after restoring the vehicle.