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Has anyone else noticed a direct correlation between the 12v battery voltage and BECM glitching?
I have been using my Dave Jones "121GW" bluetooth multimeter to graph voltages while driving.
Pretty much every glitch has been when the +12v rail drops below 12.6v, which seems to happen occasionally during daylight, when the 12v charger presumably lets the 12v battery "float".
I have found that running with the headlights on causes the 12v charger to not let the battery float and thus prevents glitching.
So my current "workaround regime", while I wait for the part is:
I know I'm risking being stranded, but so far this works, at least this gives me the chance to keep the car exercised rather than rotting while waiting for the BECM replacement.
Hmm. I should probably start a new "BECM glitch mitigation" thread about this...
I have been using my Dave Jones "121GW" bluetooth multimeter to graph voltages while driving.
Pretty much every glitch has been when the +12v rail drops below 12.6v, which seems to happen occasionally during daylight, when the 12v charger presumably lets the 12v battery "float".
I have found that running with the headlights on causes the 12v charger to not let the battery float and thus prevents glitching.
So my current "workaround regime", while I wait for the part is:
- Trickle charge the 12v battery with -12 lead disconnected when not driving (leaving about 60% SOC on traction battery). (leaving it connected while on the battery maintainer seems to work, but why not give the BECM a rest?)
- To drive, disconnect trickle charger, reconnect -12v lead.
- Right after starting the car, I turn on headlights to keep 12 rail at about 13.7v.
- During the drive, if it's long enough, I run in HOLD mode to keep the engine freshly lubed in case of RPMode.
- I can only spend a short time at the destination before the -12v rail gets down in the range of glitching the BECM while it's parked.
- I keep a GOOLOO boost-pack that does 15v with me if I need to bring the 12v rail back up above 12.6v to "bootstrap" the BECM.
I know I'm risking being stranded, but so far this works, at least this gives me the chance to keep the car exercised rather than rotting while waiting for the BECM replacement.
Hmm. I should probably start a new "BECM glitch mitigation" thread about this...