Have an engine code p0012,what could it be.on a 2001 v w beetle 1.8 have already changed the timing belt,damper,tentioner,water pump,and check engine light keeps coming on.

Check the belt alignment and also check for other worn bearings. Crankshaft damper may be coming apart.

For The 3.0 Motor. (3.3 Way down the line.)

Drain cooling system.
Remove timing belt. Refer to Engine for procedure.
Remove water pump mounting bolts.
Separate pump from water inlet pipe and remove water pump.

Timing Belt Removal
Raise vehicle and remove accessory drive belt splash shield (Fig. 66).
Remove accessory drive belts.
Remove crankshaft pulley and damper (Fig. 68).
Support engine and remove right side engine mount.
Remove engine support bracket (Fig. 67).
Remove timing belt covers (Fig. 67).
Mark belt running direction for installation (Fig. 69).
Loosen timing belt tensioner bolt (Fig. 71) and remove timing belt.
Remove crankshaft sprocket flange shield (Fig. 68). CAMSHAFT SPROCKETS To remove camshaft sprockets
Hold camshaft sprocket with Spanner Tool MB-990775. Loosen and remove bolt and washer (Fig. 70).
Remove camshaft sprocket from camshaft. To install camshaft sprockets:
Place camshaft sprocket on camshaft.
Install bolt and washer to camshaft. Using Spanner Tool MB-990775, hold camshaft sprocket and torque bolt to 95 Nm (70 ft. lbs.) (Fig. 70). TIMING BELT TENSIONER
Install timing belt tensioner and tensioner spring.
Hook spring upper end to water pump pin and lower end to tensioner bracket with hook out (Fig. 71).
Turn timing belt tensioner counterclockwise full travel in adjustment slot and tighten bolt to temporarily hold this position (Fig. 72).

INSTALLATION


Install timing belt on crankshaft sprocket and keep belt tight on tension side (Fig. 69). Install belt on the front (radiator side) camshaft sprocket. Install belt on the water pump pulley, rear camshaft sprocket and finally on the timing belt tensioner.
Rotate the front camshaft sprocket in opposite direction to take up belt slack. Check that all timing marks are aligned (Fig. 69).
Install crankshaft sprocket flange (Fig. 68).
Loosen tensioner bolt and allow spring to tension timing belt.
Turn crankshaft two full turns in clockwise direction. Turn smoothly and in clockwise direction ONLY.
Align the timing marks on the sprockets and tighten the timing belt tensioner locking bolt to 28 Nm (250 in. lbs.) torque.
Install timing belt covers.
Install engine support bracket.
Install right side engine mount.
Install crankshaft damper and pulleys (Fig. 68). Tighten damper center bolt to 135 Nm (100 ft. lbs.) .
Install accessory drive belts.
Install accessory drive belt splash shield (Fig. 66).

Be sure to also replace all the cam and crank seals why you are there. Might as well put a belt on too.

FOR THE 3.3 OR 3.8 MOTORS.

Drain Cooling System.
Remove accessory drive belt.
Remove right front lower fender shield.
Remove water pump pulley bolts and remove pulley.
Remove water pump mounting screws. Remove water pump.
Remove and discard O-ring seal.
Clean O-ring groove and O-ring surfaces on pump and chain case cover. Take care not to scratch or gouge sealing surface

Installation

Install new O-ring into groove.
Install water pump to chain case cover. Tighten screws to 12 Nm (105 inch lbs.) .
Rotate pump by hand to check for freedom of movement.
Position pulley on pump. Install screws and tighten to 30 Nm (250 inch lbs.) .
Install accessory drive belt.
Install right front lower fender shield.
Refill Cooling System.

FOR THE 2.4 MOTOR

Disconnect negative cable from battery.
Raise vehicle on a hoist. Remove right inner splash shield.
Remove accessory drive belts.
Drain cooling system.
Support engine from the bottom and remove right engine mount.
Remove right engine mount bracket.
Remove timing belt. Refer to Engine for procedure.
Remove timing belt idler pulley.
Hold camshaft sprocket with Special tool C-4687 and adaptor C-4687-1 while removing bolt. Remove both cam sprockets.
Remove rear timing belt cover.

Install new O-ring gasket in water pump body O-ring groove. CAUTION: Make sure O-ring is properly seated in water pump groove before tightening screws. An improperly located O-ring may cause damage to the O-ring and cause a coolant leak.
Assemble pump body to block and tighten screws to 12 Nm (105 inch lbs.) . Pressurize cooling system to 15 psi with pressure tester and check water pump shaft seal and O-ring for leaks.
Rotate pump by hand to check for freedom of movement.
Install rear timing belt cover.
Install camshaft sprockets and torque bolts to 101 Nm (75 ft. lbs.) .
Install timing belt idler pulley and torque mounting bolt to 61 Nm (45 ft. lbs.) .
Install timing belt. Refer to Engine for procedure.
Install right engine mount bracket and engine mount. Refer to Engine for procedure.
Fill cooling system.
Install accessory drive belts.
Lower vehicle and connect battery cable.

you should did your home work before removed old water pump most vw engines water pump is part of the timing belt assembly so when time to replace around 80k miles you should order complete timing belt kit which includes water pump with it.
so after you finish up if you didnt try to hard to run engine you may or may not damage any piece from your valve train!!even with all proper parts you have on your hand you still need high cost speciality tools to complete timing belt replacement on that engine recommendetion is tow your vehicle to mechanic shop and let them do it for you it will save you time and money!
good luck!

This is found on the autozone.com website.

2.5L Engine
See Figures 3 through 7

1. Disconnect the negative battery cable.
2. Place a large drain pan under the radiator drain plug. Drain and properly contain the engine coolant.

This procedure requires removing the engine timing belt and the auto tensioner. To help assure proper alignment at assembly, it may be helpful to set the engine at TDC on No. 1 compression stroke. This should align all timing marks on the crankshaft sprocket and both camshaft sprockets.

1. Remove the accessory drive belts and crankshaft damper.
2. Remove the right engine mount. This requires safely supporting the engine with a floor jack and wood block so the mount can be removed.
3. Remove the timing belt covers.
4. Remove the timing belt and tensioner.

Fig. Fig. 3: Remove the water pump mounting bolts

Fig. Fig. 4: Pull the water pump assembly off of the engine and inlet pipe

Fig. Fig. 5: Open the water pump housing and examine for cracks or damage

Fig. Fig. 6: Replace the water pump housing gasket using a scraper tool

Fig. Fig. 7: Always keep the water pump's mounting bolts lined up with their correct mounting holes

1. Remove the water pump mounting bolts.
2. Separate the water pump from the water inlet pipe and remove the pump.

To install:

1. Thoroughly clean all sealing surfaces. Inspect the pump for damage or cracks, signs of coolant leakage at the vent, and excessive looseness or rough turning bearings. Any problems require a new pump.
2. Install a new O-ring on the water inlet pipe. Wet the O-ring with water to make installation easier. DO NOT use oil or grease on the O-ring.
3. Install a new gasket on the water pump and fit the pump inlet opening over the water pipe. Press the assembly together to force the pipe into the water pump.
4. Install the water pump-to-engine bolts and tighten to 20 ft. lbs. (27 Nm).
5. Install the timing belt and timing belt tensioner. Set the timing belt tension.
6. Install the timing belt covers. Install the right engine mount. Remove the floor jack and engine block from underneath the engine.
7. Install the crankshaft damper.
8. Install the accessory drive belts and set to the proper tension.
9. Connect the negative battery cable.
10. Fill and bleed the engine cooling system.
11. Start the engine and verify proper operation, with no leaks

Try Chilton's or All Data for instructions. This is a 4.5 -5 hour ordeal for a professional and a 2 day mess for an amateur. Plus you must remove the timing belt on the 2.4L 4 Cylinder to get to the pump. Mess up here and you can damage your engine. WATER PUMP is sign with the ITEM 5 in the next diagram...

1. Disconnect the negative battery cable.

This procedure requires removing the engine timing belt and the auto tensioner. The factory specifies that the timing marks should always be aligned before removing the timing belt. Set the engine at TDC on No. 1 compression stroke. This should align all timing marks on the crankshaft sprocket and both camshaft sprockets.

1. Raise and safely support the vehicle to a level that allows access from above and below.
2. Remove the right inner splash shield.
3. Remove the accessory drive belts.
4. Place a drain pan under the radiator drain plug. Drain and properly contain the cooling system.
5. Support the engine using a floor jack and block of wood, then remove the right motor mount.
6. Remove the timing belt, tensioner and camshaft sprockets.

WARNING With the timing belt removed, DO NOT rotate the camshaft or crankshaft, or damage to the engine could occur.

1. Remove the rear timing belt cover to access the water pump.
2. Remove the water pump attaching bolts.
3. Remove the water pump.

Fig. 1: Water pump location on the cylinder block-4-cylinder engines





Fig. 2: Water pump assembly-4-cylinder engines


To install:

1. Thoroughly clean all sealing surfaces. Replace the water pump if there are any cracks, signs of coolant leakage from the shaft seal, loose or rough turning bearings, a damaged impeller or sprocket, or a loose or damaged sprocket flange.
2. Install a new rubber O-ring into the water pump.

Make sure the O-ring is properly seated in the water pump groove before tightening the screws. An improperly located O-ring may cause damage to the O-ring and cause a coolant leak.

1. Install the water pump and tighten the bolts to 105 inch lbs. (12 Nm).
2. Using a cooling system pressure tester, pressurize the cooling system to 15 psi and check for leaks. If okay, release the pressure and continue the engine assembly process.
3. Rotate the water pump by hand to check for freedom of movement.
4. Install the rear timing belt cover.
5. Install the camshaft sprocket(s), timing belt and tensioner. DO NOT allow the camshafts to turn while the sprocket bolts are being tightened, in order to maintain timing mark alignment.

WARNING Do not attempt to compress the tensioner plunger with the tensioner assembly installed in the engine. This will cause damage to the tensioner and other related components. The tensioner MUST be compressed in a vise.

1. Install the timing belt covers.
2. Install the right engine mount bracket and engine mount.
3. Remove the floor jack and wood block from underneath the engine.
4. Install the crankshaft damper.
5. Install the right inner splash shield.
6. Lower the vehicle.
7. Install and tension the accessory drive belts.
8. Refill the cooling system using the correct quantity and type of coolant. Bleed the cooling system.
9. Start the engine and check for proper operation.
10. Check and top off the cooling system, if necessary.

2.5L Engine
See Figures 3 through 7

1. Disconnect the negative battery cable.
2. Place a large drain pan under the radiator drain plug. Drain and properly contain the engine coolant.

This procedure requires removing the engine timing belt and the auto tensioner. To help assure proper alignment at assembly, it may be helpful to set the engine at TDC on No. 1 compression stroke. This should align all timing marks on the crankshaft sprocket and both camshaft sprockets.

1. Remove the accessory drive belts and crankshaft damper.
2. Remove the right engine mount. This requires safely supporting the engine with a floor jack and wood block so the mount can be removed.
3. Remove the timing belt covers.
4. Remove the timing belt and tensioner.

Fig. 3: Remove the water pump mounting bolts



Fig. 4: Pull the water pump assembly off of the engine and inlet pipe



Fig. 5: Open the water pump housing and examine for cracks or damage



Fig. 6: Replace the water pump housing gasket using a scraper tool



Fig. 7: Always keep the water pump's mounting bolts lined up with their correct mounting holes

1. Remove the water pump mounting bolts.
2. Separate the water pump from the water inlet pipe and remove the pump.

To install:

1. Thoroughly clean all sealing surfaces. Inspect the pump for damage or cracks, signs of coolant leakage at the vent, and excessive looseness or rough turning bearings. Any problems require a new pump.
2. Install a new O-ring on the water inlet pipe. Wet the O-ring with water to make installation easier. DO NOT use oil or grease on the O-ring.
3. Install a new gasket on the water pump and fit the pump inlet opening over the water pipe. Press the assembly together to force the pipe into the water pump.
4. Install the water pump-to-engine bolts and tighten to 20 ft. lbs. (27 Nm).
5. Install the timing belt and timing belt tensioner. Set the timing belt tension.
6. Install the timing belt covers. Install the right engine mount. Remove the floor jack and engine block from underneath the engine.
7. Install the crankshaft damper.
8. Install the accessory drive belts and set to the proper tension.
9. Connect the negative battery cable.
10. Fill and bleed the engine cooling system.
11. Start the engine and verify proper operation, with no leaks.

Hope this helps (remember to rate this answer).

first thing is the timing belt and water pump and thermostat. This job can be expensive but if not done will be catastrophic if belt breaks the next things will be : accessory belt , fuel filter, cabin filter, tentioners , battery ,cables , axles , sway bar bushings , control arm bushings , air conditioning system

could be related, or could be totally seperate issue, my advice is to go to a dealership and just get them to DIAGNOSE before you go any further ahead, not knowing what state the car was in or why you changed the belt and pump....its hard to say now......diagnose the fault codes and then we will go from there

I had the same problem on my 2000 beetle and I had to change the water pump . Once you change the water pump you have to change the timing belt because the water pump is run by the timing belt .
you could know if it is the water pump by checking the hose that comes from the radiator to the enging to se if there is water running to the engine .

ring your local audi parts dealer with your reg plate

The water pump bolts directly to the engine block, using a gasket for pump-to-block sealing, The water pump is driven by the timing belt and is serviced as a unit.Disconnect battery ground cable.Remove crankshaft drive pulleys and torsional damper,and Right Engine Mount & Bracket.Place a jack under engine to support and slightly raise engine, then remove engine mount bracket.
Remove timing belt cover, then mark belt running direction for reinstallation.
Loosen timing belt tensioner, then remove belt and crankshaft sprocket flange shield.
Drain cooling system.
Remove water pump mounting bolts.
Separate water pump from water inlet pipe, then remove water pump.
Reverse procedure to install, noting the following:
Use a new O-ring on water inlet pipe.
Torque water pump mounting bolts to 27 Nm (20 ft. lbs.).