My story about vacuum, TCS, P1540, P0300 etc.

[ujin_t@hotmail.com]

So, I got my 2000 Milly-S (Millenium) for cheap with two codes: P0306 and P1402 and bad idling.
Missfire in 6th and EGR. Nothing scarring for me, I thought.
I replaced the plugs (there were wrong ones - 1.1mm) with OEM NGKs and a coil #6. Put a new coil to the front.
Checked compression - good 180 psi. very low deviation between cylinders. Checked injectors.
OK, done... and got many new codes. They were changing from time to time, mostly like P0300, P0110, P1420.
I check all vacuum lines, solenoids, replaced most of them. Still got codes and very bad idling.
After reading about 20 threads on this forum, I decide to check all possible causes.
I started from EGR, because I had the code. Tested the sensor, and a membrane (just sucking through the pipe).
Everything works, and after all I got an idea to remove the vacuum from the EGR actuator. Bingo! The idling became stable.
But the problems did not end. When I disconnect the EGR solenoid I receive the P1426 which is ABV, not an EGR.
I scratched my had and went to check all electrical connections. Wow, there are two pairs of the same connectors: for EGR and for ABV.
They were messed up. EGR has green wires, ABV - brown and white.
Voila! Reconnect them right... and got P0300, P1540, P1525. U-f-f-f-f-f-f
Replaced the vac solenoid and 1525 gone. Replaced vent (just in case). It looks strange that the vent (KJ03) is normally open like KL02. Book says it should be NC.
Now the codes are very stable: when engine is cold - there is no codes, when it is hot and during test drive - it gives P0300 and P1540 with a Limp Home mode.
I was trying to check the ABV actuator. When sucking the pipe, it feels open. Yes, there is a vent line.
OK, I removed the ABV actuator, put the sensor to one side and sucking from the other. Ouch, I can't do -9.8 inHg, only 7-8...
Valve is movable by fingers, but not going easier when the low vacuum applied. I put it back. Check the vacuum in the main line, it looks OK: -25-30.
Now I'm trying to hear the engine carefully.
Oops, I hear a whistle near the rear intercooler connection. Vacuum lines are triple of triple times checked, it could be something else.
I feel it somewhere near the rear bypass line connected. I have the old gaskets there but with the red liquid gasket on them. One small gasket is missed and only a red gasket is there. I am not sure it is an air escaping. May be it is an internal noise...
Actually, I little bit tired of these shaman dances around this car and close to give up.

So, I have just a few questions:

- Is the vent solenoid there (KJ03) normally open or normally closed?
- How to check the ABV actuator? Is this a possible cause?
- Where can be the air leak (if it is there)? Bypass line, intake, injectors...
- Why the codes come up only on the hot engine?

[millyowner]

Your vacuum hoses might not have any leaks, but you might have a couple of them misrouted. P0300 and P1540 is a strange combo.

[ujin_t@hotmail.com]

Your vacuum hoses might not have any leaks, but you might have a couple of them misrouted. P0300 and P1540 is a strange combo.[/b]

nope
There are not so many lines in the ABV system. I check them carefully and many times.
People in other threads say that P0300 usually follows P1540 and TCS comes on, this is exactly what I have.

and I hear the whistle, pretty noticeable whistle...

[millyowner]

It's possible to trigger P1534 when there is a failure elsewhere in the system. Even a problem with the MAP sensor or the IAT sensor (compressor) can trigger P1534 when the ABV system is fully operational. You'll need to verify the routing of *every* hose, not just the ones related to the ABV.

[ujin_t@hotmail.com]

It's possible to trigger P1534 when there is a failure elsewhere in the system. Even a problem with the MAP sensor or the IAT sensor (compressor) can trigger P1534 when the ABV system is fully operational. You'll need to verify the routing of *every* hose, not just the ones related to the ABV.[/b]

today I replaced the fuel filter and intake air houses
P0300 seems to be gone
Now there are only P1540 & TCS with "limp home" when engine heat up to work temperature
I checked MAP lines and solenoid, they are OK, will check the sensor itself soon.
Do i understand right that at normal idling it could be 2.5-2.8 V, and if the solenoid is bypassed - 1.2-1.6 V (manual page F2-52)? What the picture with vacuum pump means?

[duffner]

che_rokee - how are you making out with the TCS issue? I'm working on it also... Brad.

[ujin_t@hotmail.com]

che_rokee - how are you making out with the TCS issue? I'm working on it also... Brad.[/b]

here is the end of the story:

I gave up and sold the car, I explained all problems to the next guy and he was lucky!

The problem was with an ABV actuator!
Not the solenoids/lines problem (they were fixed by me) as most people experienced.
He got a new actuator from the junk and the problem gone.

So, the most common problem is not the only problem. Look wider and good luck!