1z Tdi temperature sensor
Posted: 27 Nov 2009, 16:05
Hello,
firstly, I've had a good look to see if this question is answered and I couldn't find it on the forum so I thought I'd try posting. I've recently bought a van which had a reconditioned 1z (or possibly ahu) engine in it, but it had been botched somewhat, so I took it to Syncronutz who sorted it all out and not it drives brilliantly and I couldn't recommend them highly enough. I have one slight issue left over which is annoying me and I'd like to solve to do with the glow plug relay. I'm about to go on a long run and I wondered if I could get some reassurance or advice from more knowledgeable folk.
The glow plugs shouldn't come on when the temperature is over 5 degrees C, but currently they always come on for the maximum time. This isn't the biggest problem since once you turn the engine over they stop getting power, but it seems that the relay isn't getting the right temperature reading. What worries me is that the ECU is also not getting the right reading, although clearly the gauge on the dashboard is reading - just fractionally over middle.
I found these wiring diagrams on the web:
http://www.haywood-sullivan.com/vanagon ... _LONG4.pdf" onclick="window.open(this.href);return false;
http://volkswagen.msk.ru/electro/g3/g3_wd99_1z.pdf" onclick="window.open(this.href);return false;
which look pretty similar, but I'm a bit confused by these. I can't see how either the Engine sensor (G2) or Engine coolant Temperature (G27) control the glow plug relay or the ECU. My guess is that the coolant temperature goes to the ECU, and the Engine Temperature Sensor goes to the glow plug relay - in which case I'm not so bothered - I just don't want the ECU to think it's cool when it's not.
I'd be really grateful if anyone could either tell me not to worry about it, or tell me how to fix it. I don't have VAG-com so I can't run diagnosis on the switch itself, but might it be worth replacing it? Does the ECU drive the temperature gauge and maybe the 4-pin temperature sensor needs replacing? Would that maybe make sense?
Many many thanks in advance
Ewen
firstly, I've had a good look to see if this question is answered and I couldn't find it on the forum so I thought I'd try posting. I've recently bought a van which had a reconditioned 1z (or possibly ahu) engine in it, but it had been botched somewhat, so I took it to Syncronutz who sorted it all out and not it drives brilliantly and I couldn't recommend them highly enough. I have one slight issue left over which is annoying me and I'd like to solve to do with the glow plug relay. I'm about to go on a long run and I wondered if I could get some reassurance or advice from more knowledgeable folk.
The glow plugs shouldn't come on when the temperature is over 5 degrees C, but currently they always come on for the maximum time. This isn't the biggest problem since once you turn the engine over they stop getting power, but it seems that the relay isn't getting the right temperature reading. What worries me is that the ECU is also not getting the right reading, although clearly the gauge on the dashboard is reading - just fractionally over middle.
I found these wiring diagrams on the web:
http://www.haywood-sullivan.com/vanagon ... _LONG4.pdf" onclick="window.open(this.href);return false;
http://volkswagen.msk.ru/electro/g3/g3_wd99_1z.pdf" onclick="window.open(this.href);return false;
which look pretty similar, but I'm a bit confused by these. I can't see how either the Engine sensor (G2) or Engine coolant Temperature (G27) control the glow plug relay or the ECU. My guess is that the coolant temperature goes to the ECU, and the Engine Temperature Sensor goes to the glow plug relay - in which case I'm not so bothered - I just don't want the ECU to think it's cool when it's not.
I'd be really grateful if anyone could either tell me not to worry about it, or tell me how to fix it. I don't have VAG-com so I can't run diagnosis on the switch itself, but might it be worth replacing it? Does the ECU drive the temperature gauge and maybe the 4-pin temperature sensor needs replacing? Would that maybe make sense?
Many many thanks in advance
Ewen
