jamesmr89

This is exactly what i'm getting U1962 showed up months ago. I can't clear it with my code reader and the dealer said they didn't see it. Power steering went out a week ago, its been intermittent since, I've got a case with GM and going to dealer on Wednesday. I replaced the ground strap that I could access in the wheel well but still happening. I was able to start the truck and make it home (200 miles), it seemed to work when colder in the mornings, but didn't today.

I just wanted to followup here and see what any of your resolutions were? I'm currently in the same boat, i replaced the ground strap from youtube videos behind the passenger wheel liner, it seems like it works in the mornings but as soon as I stop and restart its no power steering. I've got an appointment in a few days and hoping someone could give me some pointers for them to look for. I'm going to insist they test voltage at the PSCM before authorizing any new parts. But anyone here find anything else to look out for? Thanks in advance.

So I just watched this. I'm at a camp ground and looked at the strap that I can easily see, I unbolted the bottom and re tightened it. Turning off the blower to reduce electrical load and the last two starts power steering has worked. Hopefully this is it. Thanks for the video.

Hey all, long-time lurker, first post. Hoping someone here (especially anyone with direct GM tech contacts) can help me sort out what's going on before I get steamrolled into a parts-cannon repair. I've done a lot of research and I think I've found the actual problem, but I want to make sure I'm not missing anything before I push back on the dealer. Truck: 2022 GMC Sierra 1500 Crew Cab 4WD, 3.0L Duramax LZ0, ~38,000 miles. VIN starts with 3GTUUDET2N. Bought new, lives in the Pacific Northwest (Kenmore/Bothell WA area), so not a heavy salt-belt truck. Symptoms (intermittent, getting worse over time): Intermittent loss of power steering assist while driving — sometimes at low speed, sometimes on the highway. Comes back after a key cycle, more rarely now, seems to be associated with it being cold, but I'm not confident, seems like 1/10 starts i get it to work. Driver-side power folding mirror sometimes fails to extend on unlock Trailer camera intermittently drops out Clock won't sync over the network "Service Power Steering" message appearing intermittently Codes pulled (over multiple scans): U1962 — Manufacturer Defined / Serial Data Authentication Configuration failure — currently set as a PERMANENT code, will not clear (This popped up back before 36k miles, warranty but dealer cdouln't see it when i was in for service.) U0131 — Lost Communication With Power Steering Control Module "A" (confirmed) (This is new, in the last 3 days) P00FF — Body Control Module Requested MIL Illumination (confirmed and pending) U1962 appearing twice in different ECUs After the first dealer ran TSB PIT5832U (Serial Data Authentication Configuration / SDAC relearn), they pulled additional chassis codes: C116A C1146 C1168 The dealer told me these are PSCM-related and recommended replacing the Power Steering Control Module / EPS rack assembly for approximately $2,250. Parts availability was unclear — they couldn't confirm when one would actually be in stock. I pushed back and asked them to complete proper diagnostics first instead of throwing parts at it. Specifically, I asked whether they had: Reprogrammed the PSCM via SPS (not just authentication) Performed PSCM setup procedures (torque sensor learn, software endstop learn, steering angle sensor centering, steering tuning configuration) Inspected ground straps per TSB 23-NA-201 and PIT6088 (I didn't know about this until after Ieft) Verified completion of recalls 22V-903 (BCM/DRL software) — could a prior BCM flash have left SDAC incomplete? Checked N242487960 (BCM software bug preventing U1962 from clearing) I didn't get clear answers on any of those, and I left without authorizing the rack replacement. What I've found on my own: I'm at a campground 4 hours from home with my travel trailer, and the truck currently runs but I'm not comfortable towing home with intermittent power steering loss. So I crawled under and looked at the body-to-chassis ground straps on the passenger side per TSB 23-NA-201. Found exactly what GM has been documenting for years — the original bare braided copper strap with visible corrosion at the eyelet and discoloration along the braid. Photo attached. This appears to match Customer Satisfaction Program N252515590 (launched January 2026), which covers 2019–2024 Sierra 1500 / Silverado 1500 for free body-to-chassis ground strap replacement with the new jacketed design (P/N 85773931), valid through February 29, 2028. Control module voltage tested at 14.3V (engine running) — charging system is healthy, so this isn't a battery/alternator issue. My theory: Every symptom I have is consistent with a corroded body-to-chassis ground causing intermittent module dropout on the CAN bus. The PSCM loses ground reference → drops off the bus → U0131. Authentication fails → U1962 sets as permanent. BCM flags it → P00FF. Other body modules with marginal ground get flaky → mirror issues, trailer camera dropouts, clock sync failures. The chassis codes (C116A/C1146/C1168) appeared only AFTER the SDAC relearn restored partial communication with the PSCM, suggesting they may be residual/cascading rather than indicative of actual hardware failure inside the module. What I'm hoping for: Has anyone had this exact code combination resolved with just the ground strap replacement under N252515590, without needing the EPS rack swap? Anyone know if there's a known issue with U1962 going permanent specifically on the T1XX trucks after a BCM software update from one of the recalls? Has anyone successfully gotten a dealer to do the proper full diagnostic sequence (SDAC + PSCM SPS reprogram + setup procedures + ground inspection) BEFORE jumping to PSCM replacement? Is there anyone at GM tech support or in the GM dealer network who's been particularly helpful with these intermittent power steering / ground strap cases? I've heard Jim has been a great resource on similar issues — would love to connect directly if possible. Any tips on getting goodwill warranty consideration? I'm at 38k miles, just past bumper-to-bumper (3yr/36k), but this is a documented widespread defect with an active CSP. Seems like a strong goodwill case. Parts availability concern: Even if PSCM replacement turns out to be necessary down the road, the dealer couldn't give me an ETA on parts. I've seen forum reports of these EPS racks being on backorder for weeks or months. Has anyone dealt with that recently? I have a stack of documentation: scan tool screenshots showing the codes (including the PERMANENT U1962), the dealer's handwritten note with TSB number and chassis codes, the photo of the corroded ground strap, and my own voltage measurements. Happy to share any of it if it helps diagnose. Any advice appreciated. Trying to make smart decisions before I authorize a $2,250+ repair on a truck that GM has acknowledged has a known free-fix for the most likely root cause. Thanks in advance.