Baffled - glowplug warning and dark current maybe
Posted: Sun Aug 20, 2023 6:28 pm
Started getting the dreaded glowplug warning and limp mode, so just doing the usual before diving-in, eg collecting diagnostic codes (the normal suspects 1114, 0400 & 1228).
I have a battery isolator, the type that unscrews at the terminal, so been collecting codes, clearing faults by isolating the battery etc.... bear with me....
When shorting the scavenger fan sensor, the glowplug light flashes, but does not trigger the fault....hmmm. if I wait long enough at idle, the warning flashes-up and the turbo actuator immediately springs fully into the turbo. When no fault and at idle the actuator appears held fully retracted by vacuum. The actuator / vanes movement feels lovely and free.
In-between this fun, have noticed that the beast still lives with the battery completely isolated, ie the dash lights up, the glowplug relay clicks and what I think is the fuel pump (or maybe ECU relay or something towards back of engine) clicks-on and hums / very feint high pitched buzzing. Turn the key several times, and all appears normal - won't start of course as battery is disconnected - what the hell? Is there a capacitor of some sort someplace?
With the battery disconnected, the only way to stop this feint buzzing and clear the dash completely is to press the brake pedal. When the fault is cleared, and battery fully connected, the feint buzzing is there during normal ignition ON, but stops a few moments after ignition OFF and removing the key.
I think the fuel pump priming or ECU relay being live with ignition OFF (ie the buzz) for a few moments is normal, but continuing with the battery completely isolated for 10mins or so is completely foxing me!!!
What else are Sundays for
... I can chase around the glowplug warnings...... but the 'dark current' is close to breaking me.... any ideas?
I have a battery isolator, the type that unscrews at the terminal, so been collecting codes, clearing faults by isolating the battery etc.... bear with me....
When shorting the scavenger fan sensor, the glowplug light flashes, but does not trigger the fault....hmmm. if I wait long enough at idle, the warning flashes-up and the turbo actuator immediately springs fully into the turbo. When no fault and at idle the actuator appears held fully retracted by vacuum. The actuator / vanes movement feels lovely and free.
In-between this fun, have noticed that the beast still lives with the battery completely isolated, ie the dash lights up, the glowplug relay clicks and what I think is the fuel pump (or maybe ECU relay or something towards back of engine) clicks-on and hums / very feint high pitched buzzing. Turn the key several times, and all appears normal - won't start of course as battery is disconnected - what the hell? Is there a capacitor of some sort someplace?
With the battery disconnected, the only way to stop this feint buzzing and clear the dash completely is to press the brake pedal. When the fault is cleared, and battery fully connected, the feint buzzing is there during normal ignition ON, but stops a few moments after ignition OFF and removing the key.
I think the fuel pump priming or ECU relay being live with ignition OFF (ie the buzz) for a few moments is normal, but continuing with the battery completely isolated for 10mins or so is completely foxing me!!!
What else are Sundays for
... I can chase around the glowplug warnings...... but the 'dark current' is close to breaking me.... any ideas?