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2003 Mercury Mountaineer PCM Failure: P0351-P0358 and P0511, P0128 - All 8 Coil Packs Failed? Diagnosing Spark and Engine Start Issues

Model: 2003 Mercury Mountaineer Fault Code: P0128 Posted: 2013-04-23 13:47

I'm experiencing multiple diagnostic trouble codes on my 2003 Mercury Mountaineer: P0351-P0358, P0511, and P0129. The presence of all eight coil pack fault codes (P0351–P0358) simultaneously is highly unusual and raises concerns about potential PCM (Powertrain Control Module) failure or a system-wide electrical issue. The vehicle will not start under normal conditions and reportedly cut off while driving, requiring towing to the shop. I have no prior service history for this vehicle. Previously, I replaced the crankshaft position sensor, but there is still no spark at the plugs, indicating a deeper issue with ignition or power delivery.

Related fault codes
P0128P0351P0352P0353P0354P0355P0356P0357P0358P0511
Comments (4)
Anonymous 2013-04-23 14:22

Multiple codes appearing suddenly — like when the vehicle was going to church and the check engine light came on unexpectedly with nine codes. Vehicle still starts and runs? Any history of recent repairs or component changes? Note: I missed P0128 initially — that makes it 10 codes in total.

Anonymous 2013-04-24 08:36

No, the vehicle will not start. The customer reports it simply stalled while driving downhill and had to be towed to the shop. No prior service records are available. I replaced the crankshaft position sensor, but there is still no spark at the plugs — indicating a potential issue with ignition system or power supply.

Anonymous 2013-04-24 09:53

This is a 4.6L engine equipped with a Coil-on-Plug (COP) system. How are you verifying spark? Basic checks to perform: > Is there 12V at the coil packs? Check the white/lt blue wire. > Is there 12V at the injectors? Check the violet/white wire.

Anonymous 2013-04-25 09:02

Have you checked for blown fuses, particularly in the ignition or powertrain circuits? A blown fuse could explain multiple fault codes and loss of spark.