Battery Problems of Mercury Mariner Hybrid

On I-66w vehicle lost engine power at highway speed. Displayed stop safely now and master vehicle electrical hazard warning lamp. The incident was extremely harrowing for the driver as the power cutoff was unexpected and immediate. Coasted to shoulder. A restart, per the owner manual, was attempted but did not work. Transported on flatbed to Ford dealership. Dealership stated hybrid battery harness, hybrid cooling fans, and throttle body needed to be replaced and pcm reprogrammed for $1900 to €œfix issue. Owner requested a new 12v front battery and warning ceased. Owner decided to do some research and test drive short distances. On 5/24 the engine cut off in an office parking lot. Vehicle was able to be restarted and go 4 miles back to residence after the carpet covering the hybrid battery was pulled up and the cabin a/c turned to high in an effort to cool the battery area (it did not feel hot but the owner believed if a temp reading was the cause a few degrees cooler might help). A wealth of info was found indicating this was a known problem and had multiple Ford technical service bulletins issued (09-18-6 Sep 09 hybrid systems - red triangle on/dtc p0a27 set€�). The owner compiled a list of 88 complaint numbers on the NHTSA site that indicate substantially similar experiences from 2005-2008 Ford escape hybrid / Mercury Mariner Hybrid owners. Believe root cause is a design flaw in the pcm s/w that removes engine power when a minor deviation from the nominal battery temp range is sensed. Likely contributing issue is a poorly designed hybrid battery cooling system (battery harness, battery cooling fans, mec pump, blend door, relays). The NHTSA is urged to open an investigation into the stop safely now/master vehicle electrical hazard engine shutdowns. Vehicle is not repaired and can be made available for inspection.

See all problems of the 2006 Mercury Mariner Hybrid 🔎.

Second unwarned total shut-down of all power on roadway - this one just 17 days after repairs and reprogramming by Ford dealership following first instance, which cut gas engine and electric motor power while traveling on los angeles freeway. This power shut-down occurred while trying to pull from parallel park spot onto busy blvd - lost all power 2 feet into traffic, able to roll back into curb before traffic reached me around semi-blind curve. After the first in-use failure on 5-17-10, I simultaneously reported the malfunction to Ford customer relations (case# 1432331380), and presented the vehicle for repair to cerritos [the following quotes from text of service record]; tech performed `eec test, revealing fault-codes: b1239, p1a0c and p0562. The tech also "found TSB (tech service bulletin) 07-25-12 with concern resolution" & he "contact[ed] Ford technical service hotline with concern. " the tech "replaced the auxiliary airflow mode door actuator and reprogrammed the traction battery control module to latest calibration 8m64-10b687-ag. Final eec test passed. " I was also informed that the part number for the replacement `airflow mode door actuator' differed from original, so the component has apparently been re-designed - but neither my wife nor I have received warnings from Ford that updates/repairs were recommended on either of our 2008 Mariner Hybrids. This originally smelled like a `silent recall' to me. . . But this doesn't even rate as a `recall', because the work performed did not prevent the second occurrence of the equivalent malfunction just 17 days later. This is a totally unacceptable failure mode for any consumer transportation vehicle, because it occurs without warning, and leaves the driver completely defenseless, and with severely-reduced response options.

See all problems of the 2008 Mercury Mariner Hybrid 🔎.