Questions and Answers

Ford Taurus DTC 1518 Q. Hi Vincent, The Service Engine Soon (SES) Indicator went on & now it is Off; I went to the mechanic who read the following code: Diagnostic Trouble Code (DTC) P1518 DTC Definition: Intake Manifold Runner Stuck Open (Bank 1)

Mechanic thinks it is related to Cruise Control. But I have not used it for a while now. I still have Extended Parts Warranty from Ford until 60,000 miles.

Question 1: What is this problem related to?

Question 2: Now that the SES Indicator is off , Is the problem gone?

• 1998 Ford Taurus
• 3.0 liter 4V engine
• Automatic transmission
• 58,500 Miles
• Fuel Injection
• ABS brakes
• P/S - A/C - Cruise control
• Rack and pinion steering

Thanks,
Sanjeev

A. The intake manifold has what is called Intake Manifold Runner Control (IMRC).

The air induction system improves engine performance by using the intake manifold runner control (IMRC) assemblies as follows:

• The intake manifold has two runners per cylinder, feeding each of the intake parts in the cylinder heads.
• The IMRC assemblies are located between the intake manifold and cylinder heads, providing two air passages for each cylinder.
• One air passage is always open and the other passage switches from closed to open by means of a valve plate.
• Below 3000 rpm , this valve plate is closed to improve low-speed and cold engine performance.
• Above 3000 rpm , this valve plate opens to improve high-speed engine performance.
• The valve plates are opened and closed by the IMRC deactivation motor, which is controlled by the powertrain control module (PCM)

There is a TSB addressing this DTC and it may or may not be due to a PCM programming error. You should take it to a Ford dealer and let them inspect the system and reprogram the PCM. The TSB is number 02-15-3 dated 08/05/02.

Article No.: 02-15-3
Date: 08/05/02
DRIVEABILITY:
Malfunction indicator lamp (mil) illuminated with diagnostic trouble code (DTC) p1518 intake manifold runner control (IMRC) - vehicles equipped with 3.0 liter 4v engine only.

FORD:
1996 - 1999 Taurus

MERCURY: 1996 - 1999 Sable

ISSUE:
Some vehicles equipped with the 3.0LE 4V Duratec engine may exhibit a Malfunction Indicator Lamp (MIL) illuminated with a Diagnostic Trouble Code (DTC) P1518, Intake Manifold Runner Control (IMRC) stuck open, with no driveability concerns present. This may be caused by the calibration of the Powertrain Control Module (PCM).

If the SES light is out, it means that the condition that turned it on no longer exists but the code will still be stored in the PCM's memory.