P1532 — IMCC Circuit Malfunction Bank B

Causes

• Open or shorted wiring in the IMCC control or feedback circuit (Bank B)
• Corroded, loose or damaged connector at the IMCC actuator or PCM
• Failed IMCC actuator/solenoid/motor on Bank B (stuck, shorted, open coil)
• Blown fuse, faulty relay or poor power/ground supply to the actuator circuit
• Intermittent harness damage (pinched, chafed) or water intrusion
• PCM internal fault or poor PCM connector contact (less common)

Symptoms

• Malfunction Indicator Lamp (MIL) illuminated
• Rough idle, unstable idle or surging
• Reduced engine performance or hesitation
• Possible stalling at idle or when decelerating
• Intake runner/idle control may not respond to commanded tests

What to check

• Retrieve freeze frame and live data with a scan tool; confirm P1532 is current
• Perform an active test/command of the IMCC (Bank B) with a capable scan tool and watch response
• Visually inspect connectors and wiring for Bank B IMCC actuator (corrosion, bent pins, water)
• Check relevant fuses and relays and battery voltage at key points
• Backprobe the actuator connector while commanding the device to observe control signal and ground
• Measure coil/actuator resistance and compare to specification (service manual)

Signal parameters

• Command type: typically PCM uses a switched power or PWM control signal to the IMCC (duty 0–100%)
• Expected control signal frequency: commonly tens to a few hundred Hz (refer to factory manual)
• When commanded ON: voltage at actuator control pin may swing between ground and reference (or show PWM duty); when OFF: near 0 V or battery voltage depending on circuit design
• Actuator coil/solenoid resistance: typically low ohms (single- to low-double-digit ohms); check factory spec for exact value
• Reference voltage to sensors/feedback (if present): often 5 V or switched battery voltage — verify with service data

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