No voltage to variable induction tuning valve

JIMB2020

MEMBER
2006 PONTIAC G6
3.9L
V6
2WD
150,000 MILES

After replacing the IMT Valve, the 2070-2078-0660 codes were not cleared. I retested the wiring : pink-black for ignition voltage (no voltage)
Black-white for ground (there is ground).
I did not proceed to the orange wire (0.5V variable tuning signal to the ECU) nor to the yellow-black wire (5.0V Fan position signal to the ECU) because there was no voltage to the IMT motor at the connector. When I connected the test light between the pink-black and black-white at the connector, it did not illuminate, but when I moved the probe at the pink-black pin to the battery positive terminal it lit up. I gather, the ground is okay at the connector, and there is an open circuit at the ignition voltage pink-black pin or wire. The question is why? The PCM relay and 10A fuse where this ignition voltage is supplied through are fine. What do I do next? Can I supply direct voltage to the pink-black wire from the positive terminal? And how would I know the IMT motor turns or not (sound?). I am not using a bi-directional scanner, so I cannot command the IMT to close.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,700 POSTS

Hi,

I attached a factory copy of the wiring schematic related to the IMT. (pic 1 and 2)

The remaining pictures are of the entire powertrain management system. Take a look at pic 5 below. You indicated there is no power to the pink/blk wire. Check fuse 45 (10amp) in the under hood fuse box. In addition to checking the fuse itself, confirm there is power to it.

Here is a link that may help you:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If there is no power, try jumping the pins for the powertrain relay (#33) in the same box to see if there is power then to the fuse. Also, here is a link that shows how to test a relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If you do get power, either check the relay via the aforementioned link or switch it with a different one having the same part number.

______________________________

If you do find there is power in and out from the fuse, then you need to check the continuity in the pink/black wire. Pull the fuse before testing that wire. Here is a helpful link:

https://www.2carpros.com/articles/how-to-check-wiring

Also, don't run 12v direct. Chances are you will damage things.

If power is to and from the fuse, then you are correct. There has to be an open in that wire. It could be the wire itself or it could be a corroded or damaged connection.

The last pic below simply identifies the fuse and relay I've discussed.

Let me know what you find or if you have other questions.

Take care and God Bless,

Joe

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