Can I reset the check engine light myself?

OBD Code P0673refers to
The Engine Control Module (ECM) has detected a fault in the cylinder #3 glow plug circuit SymptomsPossible sumptoms of OBD code P0673
- Engine Light ON (or Service Engine Soon Warning Light) - Lack/Loss of Power - The engine may be harder to start - Engine hesitation CausesPossible causes of OBD code P0673
- Cylinder #3 glow plug circuit is open or shorted - Faulty cylinder #3 glow plug - Faulty glow plug module

The code P0674 tells you that something in the glow plug circuit is faulty causing the glow plug on cylinder #4 to fail to heat up. The entire circuit must be checked to locate the fault.

Symptoms With just one glow plug failure other than the check engine light coming on, the symptoms will be minimal since the engine will normally start with one bad plug, under freezing conditions you would be more likely to experience hard starting.

Potential Causes The causes for this DTC may include: Faulty cylinder #4 glow plug Open or shorted glow plug circuit Damaged wiring connector Faulty glow plug control module Diagnostic Steps & Possible Solutions You will need a digital volt ohm meter (DVOM) for the complete test.
Continue through the tests until the problem is confirmed. You will also need a basic OBD code scanner to reset the computer and erase the code. Check the cylinder #4 glow plug by disconnecting the wire connector on the plug. Place the DVOM on ohms and place the red lead on the glow plug terminal and the black lead on a good ground. The range is .5 to 2.0 ohms, if it is out of range replace the glow plug.

have you had the glow plugs checked or replaced? the engine light'wait to start is not a joke. it means the engine glow plugs need time to heat the cylinders to max. heat to fire the engine to start. if you use either or strting fluid to start the engine in cold weather,be careful,the motor will get addicted to the starting fluid. sounds like you've not waited on the wait to start light goes off before cranking the engine.replace the glow plugs 1st and then wait before the wait to start light goes off! it's a common mistake.however the cost of glow plug replacement will be a constant reminder to wait to start. glow plugs cost about $100.00 plus labor.been there myself!! you can start engine easily in a/m with either or regular starting fluid, but please take this to heart,it's easier to replace glow plugs,than engine you can use starting fluid by spraying into the air intake of motor once,twice, but from there on,you're on your own! thank you for choosing fixya.com

glow plug light comming on when driving . starting ok. check your brake lights are working.

you are right the glow plug system should be on not after the engine starts, i suspect the timer is bad or has been bypassed,

Replace the glow plug as they get older they carode and will short under different condtions and may be shoing low voltage, and when it sets a code for the check enginge light three times the light comes on Just replace it, if it goes out it could damage your engine, this is one of those times testing does no good you have to remove it to look at it, I am a diesel truck mechanic and run into this all the time Please rate my answer for my tiem. Thanks avid101

very common for the harness that plugs onto the glow plugs to have too much resistance it will still work but will set codes

Remarkably, this problem is often associated with a faulty brake light switch down at the pedal!
It happens on my '97 Sharan from time to time and a tap on the brake pedal with my left foot stopped the glow plug light flashing.

You may need to replace the switch; but I would suggest checking the connecting wires down there first - and get someone to tell you if your brake lights come on when you press the pedal.

Hope this helps you a bit. If it does, a "Fixya" rating would be much appreciated. If it doesn't
help you, I'd be grateful if you didn't bother with a rating at present - they can't be increased later if I do manage to solve your problem! Just come back and tell me what you found. Cheers, D

how many glow plugs are there and where are their locations

You probably need to replace the glow plug harness. The contacts in the boots that connect to the glow plugs get corroded and throw off the resistance of the circuit. The controller in the VW measures whether your glow plugs are good or not by testing the resistance in the circuit. Test all the glow plugs like DickyIV1 stated and if they are all good try cleaning out the crud on the contacts in the glow plug harness. You will then either need to clear the error code or wait several trips for it to clear itself. If it never clears itself or if it comes back on after you clear it then the glow plug harness is too much of a mess. This is really common on the TDIs (mine needs to be changed but i have been putting it off and ignoring the mil light). When I first tried cleaning the harness on my car it didn't give me a problem for another year and a half. But I knew I'd eventually be changing it.
The other thing to keep in mind is that you should change out glow plugs as a set. It causes less problems in the long run since if one failed you will probably find other will soon fail and it keeps all the resistance close to the same value.