P1520 on BMW
Intake Manifold Runner Control Circuit Fault
P1520 on BMW vehicles indicates intake manifold runner control circuit fault. Au7o has documented this code across 1 BMW model — most commonly on M5. This manufacturer-specific code (common on Ford) indicates a circuit fault in the Intake Manifold Runner Control (IMRC) system, which uses motorized or vacuum-actuated flaps in the intake to vary airflow length for better low- and high-RPM performance. The computer detected that the IMRC actuator circuit is open, shorted, or not responding as commanded. You may notice reduced power, hesitation, or poor throttle response, though some drivers feel nothing. It is generally an electrical or actuator/linkage issue rather than internal engine damage. Typical repair costs on BMW range from $900 to $3,000, depending on the specific model and root cause.
Common Causes of P1520
- •Faulty IMRC actuator or motor
- •Open or shorted IMRC wiring harness
- •Poor or corroded electrical connection at the actuator
- •Stuck, broken, or seized runner flaps/linkage
- •Carbon buildup binding the runner plates
- •Faulty ECM/PCM driver (less common)
P1520 on BMW by Model
BMW M5(1 issue)
- E39 M5 VANOS Solenoid/Seal Failure Causing Rattle, Power Loss, and Check Engine Lights2000-2003
The E39 M5's S62 V8 commonly develops VANOS-related problems as mileage and age increase, especially from worn piston seals, leaking solenoid pack seals, and failing solenoids. Owners report cold-start rattle, reduced low-end torque, intermittent limp behavior, and check engine lights tied to cam timing deviations. This is a well-known E39 M5 issue discussed extensively in owner communities and supported by BMW service information covering VANOS fault diagnosis.
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View P1520 across all makes →Frequently Asked Questions
What does P1520 mean on BMW?▼
P1520 stands for "Intake Manifold Runner Control Circuit Fault." This manufacturer-specific code (common on Ford) indicates a circuit fault in the Intake Manifold Runner Control (IMRC) system, which uses motorized or vacuum-actuated flaps in the intake to vary airflow length for better low- and high-RPM performance. The computer detected that the IMRC actuator circuit is open, shorted, or not responding as commanded. You may notice reduced power, hesitation, or poor throttle response, though some drivers feel nothing. It is generally an electrical or actuator/linkage issue rather than internal engine damage. On BMW specifically, this code is documented across 1 model.
What causes P1520 on BMW vehicles?▼
Common causes on BMW: Faulty IMRC actuator or motor, Open or shorted IMRC wiring harness, Poor or corroded electrical connection at the actuator, Stuck, broken, or seized runner flaps/linkage, Carbon buildup binding the runner plates. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1520 on a BMW?▼
Repair costs on BMW range from $900 to $3,000, depending on the specific model and root cause.
Which BMW models have P1520 documented?▼
Au7o has documented P1520 on 1 BMW model: M5.