99 passat with eratic throttle and p1545 code

A/C clutch relay control.P1545.

P1545. can cause low idle or engine reving up and down between idle and 2000RPM. the problem was solved with a new throttle body. you can find reman units at 034efi.com for about $130

Check your vacuum lines for leaks. Symptoms suggest vacuum leak.

P0103 Mass or Volume Air Flow Circuit High Input P1300 Boost Calibration Fault,P1300-P1399 - Ignition System or MisfireCode Description P1416 Port Air Circuit Malfunction/ (AIR) System Bank 2 P1545 Probable Causes:1 - Failed Throttle Actuator
2 - Failed Throttle Valve Control Module Look for broken hoses, vacuum lines, leaking gaskets, anything that could cause air to escape. Check your vacuum lines carefully by using a propane UNLIT propane torch and go around every single vacuum line with the engine running. If the engine rpms increases, you have found the leak, check for any connectors that may have become unplugged or burnt or broken,, It appears that you have a circuit loss,, check the fuses

P1545 code is Throttle Pos. Contr. Malfunction.......Check Trottle valve Control Module...

p1545 is fault code for the throttle valve control system
causes can be that the throttle valve is sticking or tight, faulty/damaged wiring or the throttle control unit

That code is a Throttle Position Malfunction code.

This means one of two things:
1. The throttle body needs replaced
2. After the dead battery, you need to adapt the the throttle body.

The cheap way to do this is to leave the driver's door open, turn the key to the on position, but do not start the car. You will hear the throttle body self-adjust. This may take up to 2 minutes. That should get it close enough. To get it perfect requires a trip to the dealership.

If it does not help, the throttle body might be dead.

p1545 is a throttle control malfuction code

You can try to reset the throttle body by opening the hood and drivers door then turning your key to the accessory position. You will hear the throttle body whir and click. It may take up to two minutes. Afterward, the car will relearn your habit of driving and adjust accordingly.

I researched this & you need to replace the throttle body gasket & get the throttle body re-calibrated. Seems to be dealer only. Also, the t.p.s. (throttle position sensor) could be bad.

Did you try replacing the spark plug wires? They might be old/ frayed/ crimped. Otherwise check your intake valves for correct compression and sealing. A bad seal can cause lack in power at low RPMs.