Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSPLYMOUTH1994ACCLAIM V6-181 3.0L SOHCREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSENGINE CONTROL MODULEDESCRIPTION AND OPERATIONMODES OF OPERATIONOPEN LOOPENGINE START-UP (CRANKING)
1994 Plymouth Acclaim V6-181 3.0L SOHC
Engine Start-Up (Cranking)
1994 Plymouth Acclaim V6-181 3.0L SOHCSECTION Engine Start-Up (Cranking)
THE PCM LOOKS FOR AN IGNITION REFENCE SIGNAL:
If a signal is received within 0.5 seconds, the PCM energizes (grounds), the ASD and fuel pump relays. Supplying battery voltage to the fuel pump, fuel injector, ignition coil and oxygen sensor heating element. After the PCM energizes the ASD and fuel pump relays, the PCM fires the fuel injector 4 times per revolution, (instead of the normal 2 pulses per revolution).
If NO signal received within 0.5 seconds, the PCM does not energize the ASD and fuel pump relays.
PCM MONITORS:
- Engine Temperature (ECT Sensor)
- Manifold Vacuum (MAP Sensor)
- Throttle Position (TPS)
- Engine speed (distributor pick-up)
PCM CONTROLS:
- Injector pulse width, (switching the ground on and off twice per engine revolution).
- Idle speed, through the IAC motor.
- Ignition timing.
PCM TESTS MAP SENSOR OPERATION:
When engine idle comes within ±64 rpm of target idle speed, the PCM, compares the current MAP sensor reading to the atmospheric pressure measurement, taken during Ignition ON (Zero RPM) mode, and if a minimum difference is not detected, a MAP sensor Diagnostic Trouble Code (DTC) is set in memory
If a signal is received within 0.5 seconds, the PCM energizes (grounds), the ASD and fuel pump relays. Supplying battery voltage to the fuel pump, fuel injector, ignition coil and oxygen sensor heating element. After the PCM energizes the ASD and fuel pump relays, the PCM fires the fuel injector 4 times per revolution, (instead of the normal 2 pulses per revolution).
If NO signal received within 0.5 seconds, the PCM does not energize the ASD and fuel pump relays.
PCM MONITORS:
- Engine Temperature (ECT Sensor)
- Manifold Vacuum (MAP Sensor)
- Throttle Position (TPS)
- Engine speed (distributor pick-up)
PCM CONTROLS:
- Injector pulse width, (switching the ground on and off twice per engine revolution).
- Idle speed, through the IAC motor.
- Ignition timing.
PCM TESTS MAP SENSOR OPERATION:
When engine idle comes within ±64 rpm of target idle speed, the PCM, compares the current MAP sensor reading to the atmospheric pressure measurement, taken during Ignition ON (Zero RPM) mode, and if a minimum difference is not detected, a MAP sensor Diagnostic Trouble Code (DTC) is set in memory
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.