mauimoon

Anyone know specific behavior/spec of different solendoids as tested by a multi-meter. Other threads talk about 35-37 ohms for solenoids in the main solenoid rack but not the turbo related soleoids which mounted elsewhere (the workshop manual says are supposed to be 29-32 ohms). Additionally, are some of these supposed to show up as a closed circuit (multi-meter 'buzz' indicating a short) and others not?

More specifically:
- The multi-meter I am using has a 'buzz' feature to audibly detect a closed circuit (i.e. shorts) which is slaved to the < 200 ohm range setting that I'm using.
- The 8 solenoids in the rack test out at 36.5-37 ohms at room temperature but do not 'buzz' (i.e. open circuit).
- The TCA vacuum solenoid attached to the ACV and the two duty-cycle solenoids for the wastegate and pre-spool actuators attached to the left side of the UIM all test out at 30 ohms or so but also cause the mutli-meter to 'buzz' (i.e. circuit closed).

Is there anything from this that can be interpreted for diagnostic purposes?

Thx,
Jon

Wargasm

The way I test these when they're off the car is to measure the resistance and then to apply 12 V from a battery and see that they click and that the different ports flow air as they are supposed to. I'm not sure what your buzzer thing is telling you.

mauimoon

I'm trying to determine if it's possible to have some type of short in a solendoid that tests out okay on the bench but otherwise might fail in circuit operation.

The TCA vacuum solenoid on the ACV and the TCA pressure solenoid in the rack share the same circuit positive voltage circuit from the ECU. In my testing when the TCA vacuum solenoid is plugged into the wiring harness then the short appears on the plug that plugs into the TCA pressure solenoid which in turn may effect it's operation.

Just trying to rule out the possibilities because I have yet to find a failed component (solenoids or hoses) which can explain my secondary boost problems.


Jon

spooledUP7

Jon,
Take your TCA vacuum solenoid out, and run hot (as hot as you can) water over the main body, then chcck for continuity. Of course do not run water over the terminals. If you still get continuity while the solenoid is hot, and you are able to hear the click when applying 12 volts as Wargasm said, then the solenoid should be good.

mauimoon

Forgot to post the test results. I heated the TCA solenoid to 250F in the oven. Immediate tests while it's was hot showed good continuity but with 55ohms resistance (a little high for the given temp). About 5 minutes after coming out of the oven it was reading as a dead short again. Bottom line, the TCA solenoid is flakey and will be replaced.

rpm_pwr

all the multimeters I've used have a resistance mode AND a continuitiy mode. Continuity is always a LOT less accurate.

-pete

RonKMiller

Great advice, but also freeze individually inside a new zip lock plastic baggie for an hour as well, take them out one at time and test immediately. You don't want any condensation. Either that, or buy new ones.$$$

You want to make sure they are functional over a complete range of temperature, even if you never anticipate either extreme hot or cold in day to day use. BTW, don't use water, do the oven thing but be careful and heat them slowly. Shock heating or cooling can play hell with solenoids, especially as they age.

If they pass the hot and cold tests you can return them to service with a high degree of probability they are ok.

If they are over 100K or approaching I would replace them.

mauimoon

Only 33K miles on them.