P1520

Code

Other P — Powertrain

Intake Manifold Runner Control Circuit Malfunction

Brand: Other

Type: P — Powertrain

Views: UK: 32 EN: 53 RU: 36

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Scan for P1520 and any related codes; record freeze-frame data
Visual inspection of IMRC actuator, linkage and intake for carbon build-up or damage
Inspect connector pins for corrosion, bent pins, or water intrusion
Check fuse(s) and relay(s) supplying IMRC circuit
Backprobe connector, verify power and ground with key on
Use a scan tool to command IMRC and observe movement and PID data

Control type varies by application: low-side (ground) switch, high-side (12 V) switch, or PWM control from ECM
Expected control voltage: typically 0 V (off) and ~12 V (on) on supply line; control line may be 0–12 V or PWM
PWM frequency (when used) typically tens to a few hundred Hz; duty cycle varies with commanded position
Position sensor (if fitted) usually a variable voltage 0.5–4.5 V signal proportional to runner position
Actuator resistance: typical DC motor will measure low ohms to tens of ohms; solenoids tens to a few hundred ohms (refer to vehicle service data)

Retrieve freeze-frame and live data with a scan tool; note IMRC PID, commanded vs actual position.
Perform a visual inspection of the intake runners, actuator, linkage and wiring for damage or carbon deposits.
With key on (engine off), backprobe the actuator connector: verify battery power on the supply terminal, a good ground, and any control signal from the ECM.
Command the IMRC on/off or vary position using the scan tool while observing movement and voltage changes at the connector.
If no actuator movement but correct control signal present, disconnect actuator and apply fused 12 V (or ground, as appropriate) briefly to verify mechanical operation. Do not apply voltage if specification prohibits it.
Measure actuator (motor/solenoid) resistance and compare to spec. Check continuity from actuator terminals to the ECM pins; repair any opens or shorts.
Inspect and test any IMRC position sensor output voltage while moving the mechanism; replace sensor if signal is out of range or erratic.
If actuator is mechanically stuck, remove and inspect for carbon blocking or broken parts; clean or replace parts as required.
Repair wiring/connectors as needed, clear codes, and road-test to confirm proper operation. If ECM output is absent and wiring is good, consider ECM diagnosis/replacement per manufacturer procedures.
Review manufacturer service bulletins and wiring diagrams for model-specific tests and specifications.