IMRC Input Error (Bank 2)
The engine control unit detected a problem with the intake manifold runner control (IMRC) system on the right side of the engine, similar to a valve that isn't opening or closing properly when it should. This prevents the engine from optimizing air intake at different speeds.
The ECU monitors the IMRC valve position sensor feedback on Bank 2 to verify the intake manifold runners are switching between short and long runner modes at appropriate RPM thresholds. The sensor should show smooth transitions; if the signal is stuck, erratic, or absent, a fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| IMRC Valve Position Signal | 0.5–4.5V with smooth transitions | Signal out of range, stuck, or no response to command |
| Command-to-Feedback Response Time | < 500ms transition | > 500ms or no response |
Code P1522 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1522 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.