AC ripple peak to peak check

02 Aston DB7 (ford eecv). Car is getting a P0350 (undetermined coil circuit code), this shouldn’t happen under normal circumstances. it seems to only happen when the CKP/CMP signals are being messed with.

Both similar circumstances I can find on the internet were supposedly resolved with a new alternator.

Car is also setting random network codes in ABS/PATS and speed sensor codes when driving but can sit there KOEO forever. Decided to check AC ripple at alt B+ straight to B-.

Is this peak to peak enough to interfere with VRS sensors?

Just eyeballing your captures, it looks like there's 300-400mV AC ripple. That's definitely on the upper end of the allowable range.

There are a couple different things that can cause high ripple. A failing alternator is one. A weak battery and/or excessive electrical load is another. The battery and/or loads can increase ripple by forcing the alternator to turn up the field strength in an attempt to achieve the regulator voltage. More output - more ripple. How old is the battery? Were there a lot of electrical loads turned on when you took your measurement?

How quickly does your P0350 or speed sensor/network codes reset if you clear them? If it's pretty quickly, then you could simply try unplugging the alternator and seeing if the problem goes away. You could even go for a short trip around the block if the battery is in good condition.

during that whole 1 hour diag it disappeared with the regulator plugged in and unplugged. took it out of park drove it back on the rack it came right back…. I also have a waveform of the CMP it looked just fine.

Later on when I was reading ABS data with my scan tool it decided to quit communicating as soon as I revved to 2k in D rear wheels hanging off the rack…

hopped on identifix and iatn as a 2000 crown vic (same abs module). several instances of u1009 + 1027 codes, random stall which are this car’s symptoms. all seem to be related to spiking coils killing the SCP network.

one tech was suffering this same issue and it decided to cough up that same unusual p0350 code that they were able to track it down to #6..

i’m think i’m going to have to current ramp these coils with a trigger at a driver. at least it has a power feed for each set of 6 so that makes my life easier.