How to test a computer transistor driver (with a scan tool)

How to test a computer transistor driver with a basic test light.
This test is especially valuable when you have a faulty solenoid and cannot rely on voltage readings when the circuit is energized. Also this is the fastest way to verify wiring integrity of the control wire. A manufacturer flowchart will have you disconnect the computer and solenoid, then measure for opens and shorts with an ohmmeter. It's absolutely ridiculous that this is the standard method of testing a circuit!
Suggested test light for this application is an LED type test light.
Before performing this test, you must know what polarity to connect the test light to.
Watch this video to determine circuit design
- How to test a computer controlled solenoid (power/ground side identification)

Tests shown
- how to test a computer driver
- how to test the control wire for opens and shorts
- how to force an output driver to turn on with a scan tool
- how to force an EGR solenoid circuit to turn on

Tools used
- LED test light (preferred for computer driver testing)

Related videos
- How to test a computer controlled solenoid (circuit ID with voltmeter)
- How to test a computer transistor driver (using a scan tool)
- How to test a computer controlled solenoid (power/ground side identification)


Playlist
- (Chapter 3) Transistors, Solenoids, Computer Controlled Output Testing

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[ScannerDanner]

@TRcustomengineering Check out the other video "PCM Driver Testing II (without using a scan tool)" let me know if you have any questions, thanks!

[ScannerDanner]

They are listing this code as an internal PCM problem. The P0601 description says "Control Module Read Only Memory".
The only fix is replacement of the PCM and/or a reprogram. Although the P0602 is the only code in this list that they say is a reprogram problem.

[TRcustomengineering]

So.., Without the by-directional controls how would you do this?
Thanks

[ScannerDanner]

No just the control wire and the driver. The feed to the solenoid would be a different check.

[felplayvina]

Mr Paul after some tests the tps got my attention with to potentiometer one of them the signal got glitches from the pcm the other one the signal read 3.30 V and went I accelerator it drop to 2.40 V mi concern is why the pcm not set a code? it's possible the po601 it affected

[felplayvina]

Hi Paul 04 GMC canyon with po601 the truck start and run okay them stall and set code po601, the Michell 1 it's not helping me really much can you give a hand on this one? I going to check power and ground at the BCM.

[StuHaightVideo]

Thank you for the content you put out.

I have a pwm solenoid (diesel timing advance solenoid) that I want to protect, or say, prevent my rare EDC old diesel computer from frying in the event of a short. This is the only device that would draw high current going through that computer. Would it be beneficial to put a fuse in line between my timing advance solenoid and the EDC on both +/- sides?

Thanks,
Stu with a BMW 524TD with a Bosch VE using electronic timing advance

[ScannerDanner]

That wouldn't be related to the P0601 code. Fix the TPS issue and clear the codes and see what happens.

[seven-fukh]

hey im a new suscriber what do u mean when you said that its section 3 of your book? i wanna buy your book if that its possible

[brasanford]

Can you give me a link to where I can purchase the test light your using?

[louiemunoz]

I thought that applying 12v to the control wire can destroy the computer.🧐