P1513

What Does Code P1513 Mean?

DTC P1513 indicates that the Engine Control Module (ECM), also known as the Powertrain Control Module (PCM), has detected an anomaly within the Intake Manifold Runner Control (IMRC) system for Bank 2, specifically indicating that the intake manifold runner flaps are stuck in the closed position. The IMRC system is designed to optimize engine performance by varying the effective length of the intake manifold runners. At lower engine speeds, longer runners promote better low-end torque by increasing air velocity and promoting charge inertia. At higher engine speeds, shorter runners are utilized to minimize airflow restriction and maximize horsepower. The ECM commands the IMRC actuator to open or close these flaps based on engine RPM, load, and throttle position. When the ECM commands the Bank 2 IMRC flaps to open, and the feedback mechanism (e.g., an integrated position sensor or actuator current monitoring) indicates they remain closed, or if the actuator fails to achieve the commanded open position within a calibrated timeframe, P1513 is set. Bank 2 refers to the cylinder bank that does not contain cylinder #1, typically the passenger side on a transverse engine or the right side on a longitudinal engine (though this can vary by manufacturer).

Common Symptoms

• Check Engine Light (CEL) illumination: The primary indicator that a fault has been detected.
• Reduced engine power and acceleration: Especially noticeable at higher engine RPMs, where the engine struggles to draw sufficient air due to restricted intake runners.
• Poor high-RPM performance: The engine may feel “choked” or “flat” above a certain RPM threshold.
• Decreased fuel economy: The engine may compensate for restricted airflow, leading to less efficient combustion.
• Rough idle or stumbling: Less common, but possible if the flaps are not completely closed or if the system attempts to operate sporadically.

What Causes the Code P1513?

• Carbon buildup on IMRC flaps or pivots: Excessive carbon deposits are a very common cause, physically seizing the flaps in the closed position.
• Faulty IMRC actuator motor or solenoid (Bank 2): Electrical or mechanical failure within the actuator preventing it from moving the flaps.
• Damaged or broken IMRC linkage (Bank 2): Physical damage to the connecting rod or gears between the actuator and the runner flaps.
• Faulty IMRC position sensor (Bank 2): If equipped, a sensor that incorrectly reports the flaps as closed, even if they are actually open.
• Wiring harness issues: Open circuit, short to ground, short to voltage, or high resistance in the wiring between the ECM/PCM and the Bank 2 IMRC actuator/sensor.
• Vacuum leak or faulty vacuum switching valve (VSV) (for vacuum-operated systems): If the IMRC is vacuum-actuated, a loss of vacuum or a non-functional VSV for Bank 2 will prevent the flaps from opening.
• Failed ECM/PCM: Rare, but a faulty ECM/PCM could incorrectly command or interpret the IMRC system for Bank 2.

How to Diagnose and Troubleshoot

Diagnosis of P1513 requires a methodical approach, often involving a diagnostic scan tool and a digital multimeter (DMM).

1. Visual Inspection: Begin by thoroughly inspecting the Bank 2 IMRC assembly. Look for any visible damage to the actuator, linkage, or wiring. Check for excessive carbon buildup around the flap pivots in the intake manifold. Ensure all electrical connectors are securely seated and free from corrosion or bent pins. For vacuum-operated systems, inspect all vacuum lines for cracks, disconnections, or signs of dry rot.
2. OBD-II Scan Tool Live Data Analysis:
   • Connect a diagnostic scanner and check for other related Diagnostic Trouble Codes (DTCs).
   • Access live data parameters related to the IMRC system, such as “Intake Manifold Runner Position Sensor Bank 2” or “IMRC Actuator Duty Cycle Bank 2.”
   • With the engine running and warm, increase RPM to the threshold where the IMRC flaps are commanded open (consult service information for specific RPM). Observe if the IMRC position sensor reading changes from “closed” to “open” or if the duty cycle/voltage changes as expected.
   • If your scanner supports bi-directional control, command the Bank 2 IMRC actuator to cycle open and closed. Visually observe the actuator and linkage for movement, and monitor the position sensor feedback on the scan tool. If there’s no movement or the feedback doesn’t change, proceed to electrical testing.
3. Electrical Circuit Testing (using DMM):
   • Power Supply: Disconnect the Bank 2 IMRC actuator connector. With the ignition ON, use a DMM to check for 12V power at the appropriate pin (consult the wiring diagram).
   • Ground Circuit: Verify a good ground connection at the actuator connector by checking for continuity to chassis ground or measuring voltage (should be less than 0.1V when connected to battery negative).
   • Control Signal: If the actuator is commanded by a varying voltage or Pulse Width Modulation (PWM) signal, back-probe the control wire while commanding the actuator (via scan tool) or during appropriate engine conditions. Look for a changing voltage or PWM signal from the ECM.
   • Position Sensor Test (if separate): If there’s a dedicated IMRC position sensor, test its power, ground, and signal output. Refer to the vehicle’s service manual for specific voltage ranges at different flap positions.
   • Harness Continuity/Resistance: Disconnect the battery and both ends of the harness (ECM and IMRC actuator/sensor). Check for continuity between each pin from the ECM to the IMRC connector. Also, check for shorts to ground and shorts to power in each wire. Look for any excessive resistance that could impede proper current flow.
4. Vacuum System Testing (for vacuum-operated IMRC systems):
   • Locate the vacuum actuator for Bank 2. Use a handheld vacuum pump to directly apply vacuum to the actuator. Observe if the linkage moves smoothly through its full range. If it does not, the vacuum actuator is faulty.
   • Test the vacuum switching valve (VSV) for Bank 2. Apply 12V and ground to the VSV’s terminals and listen for an audible click. Verify with a vacuum gauge that it switches vacuum flow on and off. Check the VSV’s resistance with a DMM against specifications.
   • Inspect all vacuum lines from the vacuum source, through the VSV, to the actuator for any leaks.

Recommended Repairs and Solutions

• Clean or Replace IMRC Flaps/Assembly: If carbon buildup is confirmed as the cause, carefully remove the intake manifold and thoroughly clean the IMRC flaps, pivots, and intake runners for Bank 2. Use appropriate carbon removal solvents and brushes. If the flaps or linkages are physically broken or seized beyond cleaning, the entire IMRC assembly or even the complete intake manifold (if the IMRC is integrated) will require replacement.
• Replace Faulty IMRC Actuator Motor/Solenoid: If electrical tests confirm that the actuator is receiving the correct commands and power but fails to operate the flaps, replace the IMRC actuator for Bank 2.
• Repair or Replace Wiring Harness: Repair any detected open circuits, shorts, or excessive resistance in the wiring between the ECM/PCM and the Bank 2 IMRC component. Use professional wiring repair techniques, including solder, heat shrink, and appropriate connectors.
• Replace IMRC Position Sensor: If the sensor is found to be providing incorrect feedback, replace it. In many cases, the sensor is integral to the IMRC actuator, necessitating replacement of the entire actuator assembly.
• Repair Vacuum System Components: For vacuum-actuated systems, replace any cracked vacuum lines or a faulty vacuum switching valve (VSV) for Bank 2.
• ECM/PCM Replacement: This should be considered only as a last resort after all other components and wiring have been thoroughly tested and verified to be in good working order. A new ECM/PCM will require programming and calibration to the vehicle.

Mechanics’ Tips: Always consult the vehicle’s specific service manual for precise diagnostic procedures, wiring diagrams, torque specifications, and component locations. When replacing an intake manifold or IMRC assembly, ensure all new gaskets are used to prevent vacuum leaks, which could lead to additional issues. Some vehicles may require an IMRC system relearn or adaptation procedure using a professional scan tool after repairs.