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1998 Mustang Cobra P1516 Fault: Intake Manifold Runner Control Input Error - How to Fix

Model: 98 cobra Fault Code: P1516 Posted: 2006-04-01 13:06

I own a 1998 Mustang Cobra with a 4.6L 32V engine and approximately 100,000 miles on the odometer. My OBD-II scanner is showing fault code P1516, which indicates an 'Intake Manifold Runner Control Input Error'. I'm looking for clear, accurate information about what this error means and how to diagnose and fix it. The issue seems related to the intake manifold runner control system, which adjusts airflow based on engine load. Can anyone provide step-by-step guidance or common troubleshooting procedures? Any real-world solutions or known fixes would be greatly appreciated. Thank you in advance for your help.

Related fault codes
P1516
Comments (2)
Anonymous 2006-04-01 14:40

The P1516 code typically points to a problem with the intake manifold runner control circuit in tuned intakes, where there is a movable door inside the runners controlled by PCM commands. The error suggests that the circuit isn't functioning as expected. Without access to the wiring diagram or specific sensor connections, it's difficult to pinpoint the exact cause. This issue may stem from faulty sensors, wiring issues, or mechanical failure in the runner control mechanism.

Anonymous 2006-04-12 15:55

A friend of mine experienced the same P1516 code and discovered that one of the sensor wires inside the intake manifold had been chewed by a rodent. After splicing the damaged wire, the issue was resolved. There's also a well-known post on SVTPerformance.com (search for 'loadchris') detailing a large rat nest found beneath the intake manifold—this is unfortunately common in older vehicles with exposed wiring. Additionally, carbon buildup in the intake runners can cause them to stick open or closed, leading to performance issues and error codes. Cleaning the runners may help prevent recurrence. Check page 28 of the forum for the thread titled 'CONT. Rats under my intake...' for visual evidence.