SL/R230: No CAN to TCM. Fault Y3/8N4
Thread Starter
Senior Member
Joined: Oct 2021
Posts: 493
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From: Benton, Louisiana, USA
SL 500 2004, Ford F-150-2014
No CAN to TCM. Fault Y3/8N4
SL warriors, I have an intermittent check engine light. While extracting the codes found few things out of wack, but decided to start researching specifically on the Y3/8n4 code, which indicated a possible VGS module failure in the transmission, even though the transmission is shifting OK. After some research found some some good info and decided to look for "low hanging fruits" and one of them is the transmission cable connector possible rust. While under the car, spotted the cable, which goes from the front right side of the tranny and then upwards. Couldn't spot it from the top. For sure some of you have done this exercise and wonder if you guys can share where did you findthe other end of the transmission connector.
f that does not work, will go to CAN C contacts, and if that doesn't work, would have to take the transmission cover to access the VGS. Some experts say the Conductor Plate may be bad...and state that this is the Achiles tendon of the 722.6 tranny.!
Thank you for your support warriors!
f that does not work, will go to CAN C contacts, and if that doesn't work, would have to take the transmission cover to access the VGS. Some experts say the Conductor Plate may be bad...and state that this is the Achiles tendon of the 722.6 tranny.!
Thank you for your support warriors!
Last edited by elMacko; Sep 16, 2024 at 07:11 PM. Reason: Mispelling
Thread Starter
Senior Member
Joined: Oct 2021
Posts: 493
Likes: 101
From: Benton, Louisiana, USA
SL 500 2004, Ford F-150-2014
Mike, I would have to check if my SL-500 assembled in March 2004 has the 722.6 or the 722.9. According to my scanner there is a code Y3/8N4. Checked for the codes on the 722.9 and there is no Y3/8N4....only till Y3/8N3...! Also the Reader FOX 510 describes a VGS ...! So...I am confused now!
The funny thing is the car runs normal and shift OK!
The funny thing is the car runs normal and shift OK!
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Joined: Aug 2020
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From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
Yeah, the base SL500 went to the 722.9 for the 2004 MY in the US. Other countries might vary a bit. Unlike the 722.6, the 722.9 has an internal TCU (VGS). Most common issue on the 722.9 is bad speed sensors on the conductor plate. This is a bigger issue on the 722.9 because the TCU is integral to the conductor plate and also VIN coded. Best avenue is usually to repair instead of replace. 722.6 has an external TCU, is not VIN coded, and the conductor plate is available aftermarket and not expensive. It has the same speed sensor issues, but should just be replaced.
FYI, the conductor plate is above the valve body, so it is a bit of a project to remove and you have to be careful to make sure all check ***** stay where they belong.
Make sure that you have the correct transmission selected when you diagnose. Your scanner should give you a list of options to select from when you enter the TCU.
FYI, the conductor plate is above the valve body, so it is a bit of a project to remove and you have to be careful to make sure all check ***** stay where they belong.
Make sure that you have the correct transmission selected when you diagnose. Your scanner should give you a list of options to select from when you enter the TCU.
Thread Starter
Senior Member
Joined: Oct 2021
Posts: 493
Likes: 101
From: Benton, Louisiana, USA
SL 500 2004, Ford F-150-2014
Thank you for the advice Mike. There is a site in the WEB (circuit board medics) that refurbishes conductor plates that have great videos on how to access it and additional info on transmission codes!
