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.
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HOMESERVICE MANUALSCHEVROLET1990LUMINA APV V6-191 3.1LREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTDIAGRAMSELECTRICAL DIAGRAMSELECTRONIC/POWERTRAIN CONTROL MODULE (ECM/PCM)
1990 Chevrolet Lumina APV V6-191 3.1L
Electronic/Powertrain Control Module (ECM/PCM)
1990 Chevrolet Lumina APV V6-191 3.1LSECTION Electronic/Powertrain Control Module (ECM/PCM)
ECM Wiring Diagram (Part 1 of 3):
C16 = BATTERY +.
B1 = BATTERY +.
A1 = FUEL PUMP RELAY DRIVE.
A12 = SYSTEM GROUND.
B2 = FUEL PUMP SIGNAL (PPSW).
B8 = A/C REQUEST.
A2 = A/C CONTROL.
C2 = COOLING FAN CONTROL.
B9 = FAN REQUEST (A/C PRESSURE SWITCH SIGNAL).
ECM Wiring Diagram (Part 2 of 3):
A8 = SERIAL DATA.
A9 = DIAGNOSTIC TEST.
A12 = SYSTEM GROUND.
D1 = SYSTEM GROUND.
D6 = OXYGEN (O2) SENSOR GROUND.
D7 = OXYGEN (O2) SENSOR SIGNAL.
B10 = PARK NEUTRAL SWITCH (A/T).
A10 = VEHICLE SPEED SIGNAL 2000 RPM.
C10 = COOLANT TEMPERATURE SIGNAL.
D2 = SENSOR GROUND.
C13 = TPS SIGNAL.
C14 = + 5V REFERENCE.
C11 = MAP SIGNAL.
A11 = SENSOR GROUND.
A4 = EVRV SOLENOID.
C9 = CRANK SIGNAL.
C5 = IAC COIL "A" HI.
C6 = IAC COIL "A" LO.
C4 = IAC COIL "B" HI.
C3 = IAC COIL "B" LO.
ECM Wiring Diagram (Part 3 of 3):
A6 = IGNITION FEED.
B7 = SPARK RETARD (ESC).
D16 = INJECTOR 1 DRIVE.
D14 = INJECTOR 2 DRIVE.
A5 = SERVICE ENGINE SOON LIGHT CONTROL.
A7 = TCC.
D4 = EST.
B5 = REFERENCE.
D5 = BYPASS.
B3 = REFERENCE GROUND.
RENDER: 1.0x
NO RELATED
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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.