PWM controlled solenoids bypass test

Hi everybody,

Just wondering if PWM controlled solenoids can be bypass tested/energised using incandescent test light/jumper wire.
i'm working mostly on very new vehicles including: Jaguars, Land Rovers and Volvos and majority of solenoid fitted in those vehicles have PWM controlled solenoids.
I have recently watched Paul's video called: "CVVT system and oil control valve test 2008 Kia Optima" and in this material Paul was testing CVVT valve while it was fully disconnected from vehicle wiring, so I just asked myself if it would be ok just to provide earth path with jumper wire ( incandescent test light probably carries too small current to energise that CVVT solenoid) as that test would be faster and more convenient.
I have got 2001 Jaguar XK8 4.0 V8 currently in the garage ( I know this one is not a new vehicle at all, but it's got very nasty VVT malfunction) and I have done CVVT solenoid dynamic test same way as Paul did and it worked fine but next time would like to energise it just adding an earth to it but not sure if that's safe for computer driver.
Regards from Ireland.
Mariusz.

Hey sir, welcome to the forum!

PWM solenoids like you mentioned absolutely can be energized manually with a jumper, provided that you're observing the correct polarity. As long as polarity is correct, the PCM driver will never know the difference.

The question isn't if it's safe for the computer, but if it safe for the solenoid. Such solenoids tend to be low resistance, and can draw quite a bit of current when full fielded. Jumping the solenoids can be done, but you run the risk of burning them up if you do so for too long.

How long is too long? Tough to say. :lol: I've run the VVT solenoid on my Scion wide open for about 10 seconds, but I wouldn't do that to a customers car. I'd say if you do test VVT solenoids this way, just take care and not jump them longer than necessary to get the results.

You could limit the current using a high wattage bulb as a ballast --- start with 21 watt if that didn't work a 48 watt headlamp bulb.

Tyler wrote: Hey sir, welcome to the forum!

PWM solenoids like you mentioned absolutely can be energized manually with a jumper, provided that you're observing the correct polarity. As long as polarity is correct, the PCM driver will never know the difference.

The question isn't if it's safe for the computer, but if it safe for the solenoid. Such solenoids tend to be low resistance, and can draw quite a bit of current when full fielded. Jumping the solenoids can be done, but you run the risk of burning them up if you do so for too long.

How long is too long? Tough to say. :lol: I've run the VVT solenoid on my Scion wide open for about 10 seconds, but I wouldn't do that to a customers car. I'd say if you do test VVT solenoids this way, just take care and not jump them longer than necessary to get the results.

Agree Tyler. Only as long as necessary to determine function. 1 to 2 seconds should be enough.