Actron 9640A manual Open Loop OL, Purge Solenoid, Relay, Reluctance Sensor

Glossary

ODM:

Output Device Monitor.

Open Loop (OL):

A control system mode that does not monitor the output to verify if the desired results were achieved. A fuel delivery system will usually operate in open loop mode during cold engine warm-up because the oxygen sensors are not yet ready to send a signal. Without the oxygen sensor signal, the computer cannot check the actual results of combustion.

PCM:

Powertrain Control Module. The “brains” of the engine control system housed in a metal box with a number of sensors and actuators connected via a wiring harness. Its job is to control fuel delivery, idle speed, spark advance timing, and emission systems. The PCM receives information from sensors, then energizes various actuators to control the engine. The PCM is also known as the ECM (Engine Control Module).

Pending Codes:

Also referred to as Continuous Memory codes and Maturing Diagnostic Trouble codes. These codes are set when intermittent faults occur while driving. If the fault does not occur after a certain number of drive cycles, the code is erased from memory.

PID:

Parameter Identification. Identifies an address in memory which contains vehicle oper- ating information.

PNP:

Park/Neutral Position. This is a switch that tells the PCM when the gear shift lever is in the Park or Neutral position. When in Park or Neutral, the PCM will operate the engine in an “idle” mode.

PROM:

Programmable Read-Only Memory. The PROM contains programming information the PCM needs to operate a specific vehicle model/engine combination.

PSPS:

Power Steering Pressure Switch

Purge Solenoid:

Controls the flow of fuel vapors from the carbon canister to the intake manifold. The canister collects vapors evaporating from the fuel tank, preventing them from escaping to the atmosphere and causing pollution. During warm engine cruise conditions, the PCM energizes the Purge Solenoid so the trapped vapors are drawn into the engine and burned.

PWM:

Pulse Width Modulated

PZM:

Platform Zone Module

QDM:

Quad Driver Module

B RAM:Random Access Memory

Relay:

An electromechanical device in which connections in one circuit are switched

Reluctance Sensor:

A type of sensor typically used to measure crankshaft or camshaft Speed and/or position, driveshaft speed, and wheel speed

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