PCM What Info Do They Monitor

[TERRY4]

Just would like to know what info do pcm's read or store.Reed another forum where a person added the scangauge2 to his OBD2 port to watch trans temps.There is also aeroforce tech.called inteceptor.seems to be a good idea. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

[SmokeyWren]

For a '99-'03 7.3L:

Diesel PCM Inputs

Air Conditioning Pressure Switch

Brake Lamp Switch

Camshaft Position Sensor

Clutch Pedal Position Switch

Intake Air Temperature Sensor

Transmission Control Switch

Vehicle Speed Sensor

4x4 Low Switch

Electronic Throttle Control (ETC) — All, Except E-Series

Idle Validation Switch

Exhaust Back-Pressure Sensor

Injection Control Pressure Sensor

Engine Oil Temperature Sensor

Analog Manifold Absolute Pressure Sensor

Barometric Pressure Sensor

Parking Brake Signal Switch

Brake Pressure Applied Switch

Speed Control Command Switches

Injector Driver Module Feedback

Manifold Air Temperature (MAT) Sensor

Diesel PCM Outputs

Injector Driver Module

Exhaust Back Pressure Regulator

Injection Pressure Regulator

Tachometer

Water in Fuel Indicator

Electronic Air Filter Minder

Glow Plug Relay Control — Federal

Glow Plug Indicator

Manifold Intake Air Heater (MIAH)

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That's per the list in "the book". But we know the PCM (with supporting computers such as the ABS module) controls other things not listed. For example, speedometer and tripmeter and odometer based on VSS input. And when you touch the brakes (brake pressure applied switch) the PCM kills the cruise control. And if an auxiliary idle controller (AIC) is activated, when you touch the brakes the PCM returns elevated idle to normal idle. And in the wintertime, if the cold ambient program (CAP) routine in the PCM has elevated the engine idle RPM, touching the brakes will kill the elevated idle. And one output not listed is the PCM decides when to lock and unlock the torque converter, based on tranny temp, speed, torque produced by the engine, brakes applied, etc.

Oh, and if your cruise control doesn't work, check to be sure the E-brake is not mashed in a tiny bit (parking brake signal switch), because that will kill the cruise control. Don't ask how I know. [img]/ubbthreads/images/graemlins/blush.gif[/img]