ISSUE:

Some 2008-2010 Crown Victoria, Grand Marquis, Town Car, Taurus and MKZ, 2008-2009 Sable and 2009-2010 MKS vehicles equipped with the rear window on-glass AM/FM antenna may exhibit significant FM static and potentially static on AM stations when the back glass defrost grid is turned on.

ACTION:

Follow the Service Procedure outlined below to resolve the customer concern.

SERVICE PROCEDURE

Before performing this repair procedure, review the Warranty Policy Manual for Warrantable / Non Warrantable defroster grid line repairs.

The grid line material is not embedded into the glass but is baked to the glass surface and consequently can be scraped off. Inoperative line may appear to the eye to be undamaged due to residue remaining on the glass and will require diagnosis with a voltmeter or a 12v test as explained in this article.

An undamaged grid line will have small ridges that project above the surface of the glass and can easily be felt when running a fingernail across them. Grid lines that have been razor bladed will feel smooth when a fingernail is dragged across the affected area. There may be some residue left on the glass that appears to be grid material but a check with a voltmeter or test lamp, as explained in this article will confirm an open circuit.

Some reception concerns can be caused by aftermarket tinting of the back glass. Many aftermarket tinting products are a metallic composite material causing the antenna to short out to the defroster grid. To service this tint must be removed with great care taken not to damage the defroster grid lines.

Some vehicles have been found to have glass defrost patterns with gaps in the rear defrost grid. Electrical current still flows through these gaps to allow the defrost function to work on each wire, but very small sparks jump the gap and cause electromagnetic noise. This noise sounds like static which couples to the on-glass AM/FM antenna. Heavy moisture or metallic composite material tint on the glass may make the static more severe, but only when the defrost grid is turned on. Generally, the antenna module, coax, radio or climate control head replacement is not an effective repair for these symptoms.

1. Turn the radio on and tune to a clear FM station using the Seek function.
2. Activate the defrost function and verify that there is a degradation of radio reception quality (static) with the back glass defrost grid On.
3. Deactivate the defrost function and verify that the radio reception quality is improved (less or no static) with the back glass defrost grid Off.
   1. If the radio reception is not affected by the status of the defrost continue following normal diagnostic in the Workshop Manual (WSM), Section 415-00.
   2. If the radio reception is clearly affected by the status of the defrost function, go to Step 4.
4. Inspect the defroster grid tabs and connector for a secure connection.
   1. If the grid tabs are not secure, follow WSM, Section 501-11 to repair the concern.
   2. If the grid tabs are secure, go to Step 5.
5. Use WSM, Section 501-11 to inspect and test the grid lines.
   1. If damage is found to the grid lines, follow WSM, Section 501-11 to repair.
   2. If no damage is found to the grid lines, replace the back glass as per the WSM, Section 501-11. In some case microscopic gaps in the rear defrost grid can cause electromagnetic noise. The grid line test will not detect this concern and the rear glass will have to be replaced.

WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

DEALER CODING

NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and equipment to do the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information that could assist in proper vehicle service. The procedures should not be performed by "do-it-yourselfers". Do not assume that a condition described affects your car or truck. Contact a Ford, Lincoln, or Mercury dealership to determine whether the Bulletin applies to your vehicle. Warranty Policy and Extended Service Plan documentation determine Warranty and/or Extended Service Plan coverage unless stated otherwise in the TSB article. The information in this Technical Service Bulletin (TSB) was current at the time of printing. Ford Motor Company reserves the right to supercede this information with updates. The most recent information is available through Ford Motor Company's on-line technical resources.

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