Tech Tip: 2005-06 Ford Escape/Mercury Mariner ECM Problem – UnderhoodService

Tech Tip: 2005-06 Ford Escape/Mercury Mariner ECM Problem

Vehicle owners may experience misfire and poor engine performance. Fault codes may be set for coil-on-plug (COP) or Powertrain Control Module (PCM). No change in performance after replacing components or repeated failure of replacement components.

Application:
78-1044F for 2005-2006 Ford Escape and Mercury Mariner 2WD 3.0L

Problem:
Misfire, poor engine performance. Setting fault codes for coil-on-plug (COP) or Powertrain Control Module (PCM). No change in performance after replacing components or repeated failure of replacement components.

Cause:
Incorrect spark plugs may cause damage to the COP(s) and PCM.

Solution:
Ford TSB 09-2-6 refers to COP and PCM damage due to the installation of incorrect spark plugs. The wrong plugs generate excessive RF interference, resulting in damage to the PCM and COP(s). Unless these spark plugs are upgraded, the failure of perfectly good replacement components will continue. The TSB involves checking for the presence of a date code (example shown in Figure 1). If no date code of any kind is present, the plugs must be replaced. Also, depending on how many COP codes are set, it may be necessary to replace one or more COP(s) and the ECM. Please refer to the TSB and the vehicle service manual for complete detailed instructions.

Note:
This ProTech bulletin is supplied as technical information only and is not an authorization for repair.

Tech Tip courtesy of CARDONE Industries, Inc.

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