1.9 AHU, possible needle lift sensor issue!
Posted: 31 Aug 2026, 15:08
Hi all! Long time no posts, I’m a tdi owner nowadays.
I’m trying to troubleshoot an issue.
Does anyone know, for 100% certainty if I have the ignition on and engine off, what voltage should I read when placing a multimeter across the unplugged connector for the needle lift sensor, on the loom side? I am seeing 11.3 volts, from research I should be seeing 3.2 to 5 volts.
Sensor resistance itself reads good.
I am trying to troubleshoot code 00550 start of injection, control difference which I believe is pegging the injection pump to full advance.
I do not suspect the timing has slipped as the issue was intermittent at first. In any case my next point of call would be to check static timing but before I start doing that this voltage at the needle lift sensor is bugging me.
Any ideas?
Ed.
I’m trying to troubleshoot an issue.
Does anyone know, for 100% certainty if I have the ignition on and engine off, what voltage should I read when placing a multimeter across the unplugged connector for the needle lift sensor, on the loom side? I am seeing 11.3 volts, from research I should be seeing 3.2 to 5 volts.
Sensor resistance itself reads good.
I am trying to troubleshoot code 00550 start of injection, control difference which I believe is pegging the injection pump to full advance.
I do not suspect the timing has slipped as the issue was intermittent at first. In any case my next point of call would be to check static timing but before I start doing that this voltage at the needle lift sensor is bugging me.
Any ideas?
Ed.