bhef
Well-known member
So my 2000 Jetta TDI refuses to start besides the 2 times out of probably 40 tries.
Symptoms:
1)No MIL Light
2)No Glow Plug Light
3)No power to relay 109 fuses
4)No Start (Will crank just fine)
5)Programmer cannot communicate with ECU
6)Fuse 29 only weakly illuminates test probe light
7)Windows fail to roll up or down (worked at first when having no start problem)
8)Relay 109 will not engage with key turned to ON
NOTE: Called dealer who saw this car before I bought it and said "loose wires under dash. Just wiggle them around"
-Tried this so many times and only once did it briefly cause the glow plug light and MIL light to illuminate with key turned to on (still no start)
What I've done:
Confirmed power to relay 109 (12.4V)
Confirmed relay 109 works by swapping with one from working vehicle (1st try the car started and only once since then)
Confirmed fuses are good
Checked for power at corresponding fuses powered through relay 109 (only power present when manually engaging relay I took the cover off of)
Confirmed good ground at relay 109 socket (VERY little resistance, audible continuity setting beeps)
Checked for evidence of mice chewing wires in engine bay (none found)
Checked grounds under battery (great condition)
Checked fuseable link fuses on top of battery (all good no resistance across)
What I have left to try:
Confirm continuity to ECU from relay 109 on the small blue wire (rig dummy wire up between those components to confirm the wire is bad if dummy wire fixes problem)
Confirm Socket pins are not loose so that relay actually makes full contact on every blade
ANY help and direction would be so appreciated and if anyone can tell me how much power is sent to relay 109 from ECU or if the relay actually sends power to the ECU that would be helpful. Basically, if someone could explain how the ECU (and what requirements are needed for) ties into activating relay 109 that would be great
I JUST got this car and it's amazing when it worked before this problem last night causing me to need a tow home. Roughly 190hp manual conversion NO corner cut in restore/tune/mod/conversion/perf upgrades. Only 40k miles on everything except frame, body and window glass. PLEASE help me get this back on the road.
Symptoms:
1)No MIL Light
2)No Glow Plug Light
3)No power to relay 109 fuses
4)No Start (Will crank just fine)
5)Programmer cannot communicate with ECU
6)Fuse 29 only weakly illuminates test probe light
7)Windows fail to roll up or down (worked at first when having no start problem)
8)Relay 109 will not engage with key turned to ON
NOTE: Called dealer who saw this car before I bought it and said "loose wires under dash. Just wiggle them around"
-Tried this so many times and only once did it briefly cause the glow plug light and MIL light to illuminate with key turned to on (still no start)
What I've done:
Confirmed power to relay 109 (12.4V)
Confirmed relay 109 works by swapping with one from working vehicle (1st try the car started and only once since then)
Confirmed fuses are good
Checked for power at corresponding fuses powered through relay 109 (only power present when manually engaging relay I took the cover off of)
Confirmed good ground at relay 109 socket (VERY little resistance, audible continuity setting beeps)
Checked for evidence of mice chewing wires in engine bay (none found)
Checked grounds under battery (great condition)
Checked fuseable link fuses on top of battery (all good no resistance across)
What I have left to try:
Confirm continuity to ECU from relay 109 on the small blue wire (rig dummy wire up between those components to confirm the wire is bad if dummy wire fixes problem)
Confirm Socket pins are not loose so that relay actually makes full contact on every blade
ANY help and direction would be so appreciated and if anyone can tell me how much power is sent to relay 109 from ECU or if the relay actually sends power to the ECU that would be helpful. Basically, if someone could explain how the ECU (and what requirements are needed for) ties into activating relay 109 that would be great
I JUST got this car and it's amazing when it worked before this problem last night causing me to need a tow home. Roughly 190hp manual conversion NO corner cut in restore/tune/mod/conversion/perf upgrades. Only 40k miles on everything except frame, body and window glass. PLEASE help me get this back on the road.
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