Hybrid System - Start/Stall/DTC P0A7D/P1A0C Misdiagnosis
TSB 11-11-811/10/11
HYBRID - POSSIBLE MISDIAGNOSIS OF
START/STALL WITH OR WITHOUT DTCS P0A7D,
P1A0C
FORD:
2010-2012 Fusion
2005-2007 Escape Hybrid
2008 Escape
2009-2012 Escape
LINCOLN:
2011-2012 MKZ
MERCURY:
2010-2011 Milan
2006-2007 Mariner Hybrid
2008 Mariner
2009-2011 Mariner
ISSUE
Some 2005-2012 Escape, Mariner Hybrid, 2010-2012 Fusion, Milan and MKZ Hybrid vehicles may exhibit a concern where the engine stalls soon after starting. This may actually be a crank/no-start condition being misdiagnosed due to the unique design characteristics of the Hybrid powertrain system. DTC P0A7D (battery pack state of charge low) and/or P1A0C (engine disabled) may be present.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
^ Conventional gasoline engines use an externally mounted starter motor which can easily be heard when starting the engine.
^ The Hybrid powertrain has no external starter motor, and instead utilizes the motor/generator contained within the eCVT transaxle for this function. The motor/generator is almost silent in operation.
^ This higher rotational speed along with the lack of audible starter motor noise may be mistaken for the engine actually having been successfully started then stalling. A conventional externally mounted starter motor rotates the engine at 200-250 RPM when starting the engine. The Hybrid eCVT motor/generator rotates the engine at 900-1,200 RPM for up to 30 seconds when starting.
^ If the perceived stall occurs with a cold engine within 30 seconds or less after starting is initiated, the engine is most likely in a crank/no start mode and is not a start/stall.
^ Inadvertently following the Powertrain Control/Emissions Diagnostic (PC/ED) Manual, Section 3 symptom chart for a stall/quit at idle instead of no start/normal crank may eventually discharge the high voltage traction battery, resulting in DTC POA7D and/or P1AOC. This may lead to the possible replacement of the high voltage traction battery.
WARRANTY STATUS: Information Only
Disclaimer