Smooth_Rider
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Thank you!
Update: 99 Yukon NP8 codes 1-2 shift scan tool?
- Thread starter Smooth_Rider
- Start date
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Smooth_Rider
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Ok so I have an update to anyone who responded to OP or anyone who want to chime in and offer help.
I took y'alls advice to heart, bucked up, got with the times and got my first "real" scan tool, it is (to me) crazy what this thing sees and can manipulate on my old 1999 yuk. The problem was service 4wd light on, 4wd buttons act dead (no lights, no shifting). The scan tool (Launch C Reader Elite GM edition) confirms the 4wd dash switchs ok. I have no communication to coder motor or front diff solenoid and pull the following codes:
P1875 4wd low switch circuit
U1192 loss of passlock/evo class2 comms
U1026 loss of class2 comms with ATC
C0323 tcase lock circuit low
I'm not proporting to know what these codes mean or in relation to each other. The truck did pass all the tests under the Passlock test section which was a little confusing to me given the above description under U1192.
As I think I detailed early in OP I can sometimes hear a relay clicking under dash when I start the truck. This is since the shifting/4wd issue began. After basic research into these codes with my limited knowledge and resources, it seemed that the TCCM kept coming up, and when I realized that its in the location where I was hearing the relays click....today I took the driver seat out and tore the dash half apart to find that f*cking thing, yep, its buried up in there..but sure enough when I put my hand on it and started the engine- I could FEEL click click click.
So...I think the TCCM is fried and not communicating properly- my best guess at this point. Thoughts? I did read that they don't need to be programmed, so theoretically you could buy a used working one from ebay for $40-ish, disconnect the battery, and install it. I also have a AC Delco decoder ring coming tomorrow as it was only $15 and seem to be a common enough failure I might as well have it anyways.
I took y'alls advice to heart, bucked up, got with the times and got my first "real" scan tool, it is (to me) crazy what this thing sees and can manipulate on my old 1999 yuk. The problem was service 4wd light on, 4wd buttons act dead (no lights, no shifting). The scan tool (Launch C Reader Elite GM edition) confirms the 4wd dash switchs ok. I have no communication to coder motor or front diff solenoid and pull the following codes:
P1875 4wd low switch circuit
U1192 loss of passlock/evo class2 comms
U1026 loss of class2 comms with ATC
C0323 tcase lock circuit low
I'm not proporting to know what these codes mean or in relation to each other. The truck did pass all the tests under the Passlock test section which was a little confusing to me given the above description under U1192.
As I think I detailed early in OP I can sometimes hear a relay clicking under dash when I start the truck. This is since the shifting/4wd issue began. After basic research into these codes with my limited knowledge and resources, it seemed that the TCCM kept coming up, and when I realized that its in the location where I was hearing the relays click....today I took the driver seat out and tore the dash half apart to find that f*cking thing, yep, its buried up in there..but sure enough when I put my hand on it and started the engine- I could FEEL click click click.
So...I think the TCCM is fried and not communicating properly- my best guess at this point. Thoughts? I did read that they don't need to be programmed, so theoretically you could buy a used working one from ebay for $40-ish, disconnect the battery, and install it. I also have a AC Delco decoder ring coming tomorrow as it was only $15 and seem to be a common enough failure I might as well have it anyways.
Foot0069
Member
Dang I wish you luck. I've just read both of your posts and surely have nothing to offer. I'm trying to get better at these electron boxes but.... I found out the hard way about the proper scan tools to set the distributor cam retard angle. Do you know if your tool is capable of reading it. And is this the one you bought? I operate on a limited budget, so inexpensive is the way for me on most tools that are little used.
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Smooth_Rider
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- Sep 11, 2023
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Yes, that's not only the tool I bought, but appears to be the exact listing on Azn. It was shipped from china for $145 plus tax. They seem to have constant promotions. I have no idea on cam angle (not where I was looking) but would assume yes based on what this thing can do. I posted a pretty detailed review of this scanner on AMZ under my moniker SmoothRider, just recently that would be worth reading.
