Hopefully, someone can help.

I have a 2010 Nissan Armada 2wd with the code P1574, no other codes.
Cruise "SET" will flash when turned on when the code sets.

The speedometer was 9-10 mph as the screenshot shows. Can anyone provide some insight on where to start with this repair?

P1574 means there's a big difference between the transmission-indicated speed and the ABS-indicated speed. So the problem has to be in your ABS. The tranny is showing about the same speed as the ECM, and that gets to the ECM by way of the cluster. That should vindicate all three of those devices. If your scanner doesn't do ABS, you need to get a scan from one that does.

VStar650CL wrote: ↑

Thu Jul 27, 2023 4:18 pm

P1574 means there's a big difference between the transmission-indicated speed and the ABS-indicated speed. So the problem has to be in your ABS. The tranny is showing about the same speed as the ECM, and that gets to the ECM by way of the cluster. That should vindicate all three of those devices. If your scanner doesn't do ABS, you need to get a scan from one that does.

Thank you. It does do ABS. Does the Vehicle Speed PID come from the ABS Module via the wheel speed sensors?

What PID(S) should I pull up to show this information?

Well, wait a second, most of them throw codes for a 10% difference but some of them throw it for 5%. I just checked the FSM for your Armada and I can't find a spec, but running 9.94/9.32 through the calculator gives 6.7%. The Armada also appears to be set up a$$ backwards from most other Nissan models, the ABS actually provides the speedo signal to the cluster and not the tranny. So I think my first reply was steering you the wrong way, that 9.94 must be from the ABS. The tranny isn't good at detecting a VSS that's missing pulses, only if it's flatlining. Since the tranny is indicating the lower value and there are no wheel sensor codes, I think maybe your VSS is missing a pulse here and there and causing an undercount. The way to check is to watch the numbers while clocking your speed with GPS, normally all Nissans read about 1 mph low. If the ABS speed looks to be about right for that but the tranny speed is consistently lower, then the problem is most likely the OSS sensor in the Valve Body.

What's strange to me is the vehicle drives great, shifts great. I have noticed that when the vehicle stays below 47ish MPH it won't throw this code and the cruise will work just fine. I'm going to post some more screenshots from the scanner recording I did earlier.

Hopefully, you can understand this.

The thing is, the speed readings should be tracking one another pretty closely, and they aren't. Nissan ABS's are very sensitive to reluctor issues, even one missed tooth will generate a wheel sensor code. The tranny isn't. Unless the OSS flatlines, the TCM won't generally notice, and missed teeth will only result in a reduced or fluctuating speed reading. It looks to me like that's what happening. Checking against a GPS should verify it, if the ABS speed tracks with the GPS but the OSS speed is off or unstable, that would be a smoking gun that the OSS is causing the code.

VStar650CL wrote: ↑

Fri Jul 28, 2023 4:01 am

The thing is, the speed readings should be tracking one another pretty closely, and they aren't. Nissan ABS's are very sensitive to reluctor issues, even one missed tooth will generate a wheel sensor code. The tranny isn't. Unless the OSS flatlines, the TCM won't generally notice, and missed teeth will only result in a reduced or fluctuating speed reading. It looks to me like that's what happening. Checking against a GPS should verify it, if the ABS speed tracks with the GPS but the OSS speed is off or unstable, that would be a smoking gun that the OSS is causing the code.

Thanks for the info. I checked ABS wheel speeds with GPS and they were matching speeds.

I went out and recorded more live data. I have plenty of data if needed. It happens right when the speed hits 47.22 mph, according to Freeze Frame Data.

I included a recorded frame when it hit 47.22 mph & the next frame right when I started slowing down.

In the second frame you can pretty clearly see the tranny speed start diverging from the ABS speed after tracking closely in frame one. That looks to me like the VSS in your tranny is malfunctioning at higher road speeds and starts missing teeth on the reluctor wheel, at which time the ECM notices the difference exceeds 5% and throws the code. It's not at all uncommon for Hall sensors to fail that way, they "load up" magnetically and start losing track of the reluctor. I'm pretty sure you need a Valve Body, I don't think the VSS is available as a service part.

I see the TCM has 2 input sensors on top of it and an OSS sensor mounted in the tail housing. I replaced the one in the tail housing, which didn't solve anything.

The documentation for which sensor is being read is very fuzzy, the reading is actually being passed on CAN and the documentation treats the TCM as an assembly. Less than helpful, but the one thing it does say is "replace the Valve Body" if the problem is in the tranny sensor. So I'd assume it's one of the ones on the TCM.

I installed a supposedly "known good" valve body in the vehicle. Code P1574 still comes back but, after driving a bit, code P1721 will show up as well.

P1721 is a flatline code for the same sensor. It means it isn't simply missing teeth now, it's also quitting completely for some period. That smells like wiring, and the only part of the wiring you would have touched is the stuff inside the pan. So I think you must have a problem with a cracked wire or a bad pin-fit someplace on the TCM subharness.

VStar650CL wrote: ↑

Tue Aug 08, 2023 5:50 pm

P1721 is a flatline code for the same sensor. It means it isn't simply missing teeth now, it's also quitting completely for some period. That smells like wiring, and the only part of the wiring you would have touched is the stuff inside the pan. So I think you must have a problem with a cracked wire or a bad pin-fit someplace on the TCM subharness.

Yes, the only harness I touched was inside the trans. I didn't bother with unplugging the outside trans harness.

VStar650CL wrote: ↑

Tue Aug 08, 2023 5:50 pm

P1721 is a flatline code for the same sensor. It means it isn't simply missing teeth now, it's also quitting completely for some period. That smells like wiring, and the only part of the wiring you would have touched is the stuff inside the pan. So I think you must have a problem with a cracked wire or a bad pin-fit someplace on the TCM subharness.

Why would this VHCL Speed SE show 18.63 mph in park at idle?

Something in there has to making intermittent or resistive contact, engine vibration will cause a reading if either the power or data wires to the sensor are going open. The My first guess would be a bad pin fit.

What do you think about this speed sensor data?

It's all over the lot, but that's probably a CAN artifact. The ABS throws codes if it misses even one tooth, or if there's the slightest wheel speed mismatch with the yaw and steering angle. If you think I'm kidding, try reversing sides on your rear wheel sensors for s#!ts and giggles. One of our techs did that once by accident when replacing a rear subframe, and the ABS lamp would light up the instant you went above 10 mph and turned the wheel about 2 degrees. The tiny speed differential between the two wheels wired opposite instantly triggered it. Since you have no ABS codes, the only way that can be the problem is if your ABS has completely lost its mind. I kind of doubt that. In your earlier FF plots it was clearly the tranny speed that plummeted when the DTC occurred, not the ABS.

VStar650CL wrote: ↑

Sun Aug 13, 2023 8:56 pm

It's all over the lot, but that's probably a CAN artifact. The ABS throws codes if it misses even one tooth, or if there's the slightest wheel speed mismatch with the yaw and steering angle. If you think I'm kidding, try reversing sides on your rear wheel sensors for s#!ts and giggles. One of our techs did that once by accident when replacing a rear subframe, and the ABS lamp would light up the instant you went above 10 mph and turned the wheel about 2 degrees. The tiny speed differential between the two wheels wired opposite instantly triggered it. Since you have no ABS codes, the only way that can be the problem is if your ABS has completely lost its mind. I kind of doubt that. In your earlier FF plots, it was clearly the tranny speed that plummeted when the DTC occurred, not the ABS.

I probably should have used my wired Autel instead of my Bluetooth one for live data. What do you think the percentage is that the ECM is bad?

The ECM is just getting a CAN message about the speed, the tranny, ABS, and cluster are the actual participants. The ECM is an observer, the odds of it being the issue are pretty much zero.

Here is live data from the ECM inputs. I wish it would name the PIDS so you would know what was the culprit part.

You can see when the code sets, Freeze Frame shows 47.22mph.

Your first FF's showed MTR and A/T, and I'd have to assume A/T is Automatic Transmission. Since that was the speed which was misbehaving on the graphs, I'd also have to assume the VSS in the tranny is the one acting up. The question is why, and with a new VB, the only things left are internal wiring or connectors, or mechanical wear in the output shaft. So unless your scanner is lying about the data sources, that's pretty clear cut and more data isn't going to help. On the other hand, if your scanner is confused about who it's talking to, then you won't be getting to the bottom of it without a better scanner.

VStar650CL wrote: ↑

Thu Aug 17, 2023 5:45 pm

Your first FF's showed MTR and A/T, and I'd have to assume A/T is Automatic Transmission. Since that was the speed which was misbehaving on the graphs, I'd also have to assume the VSS in the tranny is the one acting up. The question is why, and with a new VB, the only things left are internal wiring or connectors, or mechanical wear in the output shaft. So unless your scanner is lying about the data sources, that's pretty clear cut and more data isn't going to help. On the other hand, if your scanner is confused about who it's talking to, then you won't be getting to the bottom of it without a better scanner.

Both my Autel & Launch scanners read the PIDs with the same name.

Maybe I need to get Consult and see what it shows.

The most common cause of this code is a faulty brake pedal switch. Inspect the brake pedal switch for any visible damage or signs of wear. Make sure it's properly adjusted and functioning as it should. You may need to replace it if it's defective. Examine the wiring and connectors associated with the brake pedal switch and the cruise control system. Look for damaged wires, loose connections, or corrosion. Repair or replace any damaged components as necessary. After inspecting and potentially repairing any issues, you should clear the error code from the ECM's memory. You can do this with an OBD-II scanner or by disconnecting the vehicle's battery for a few minutes.

akkoeis wrote: ↑

Sat Oct 28, 2023 7:51 am

The most common cause of this code is a faulty brake pedal switch. Inspect the brake pedal switch for any visible damage or signs of wear. Make sure it's properly adjusted and functioning as it should. You may need to replace it if it's defective. Examine the wiring and connectors associated with the brake pedal switch and the cruise control system. Look for damaged wires, loose connections, or corrosion. Repair or replace any damaged components as necessary. After inspecting and potentially repairing any issues, you should clear the error code from the ECM's memory. You can do this with an OBD-II scanner or by disconnecting the vehicle's battery for a few minutes.

Identifix has zero instances of P1574 being caused by a brake switch, and I've never heard of it either. It is common for gen1 Titan/Armadas and gen2 Armadas to throw C1142 from a bad brake switch, essentially blaming the wrong component (pressure sensor) for the problem. Aside from that, I have no idea what you could be talking about.

You also mentioned a specific situation where the C1142 code might be erroneously thrown due to a bad brake switch. What about online gamb|ing? I've found some information about https://casinosanalyzer.com/online-casi ... k-transfer fast bank transfer casinos recently and I think I should check it out. I can't say I'm an avid casino player, but sometimes I enjoy it a lot. It's possible that in some vehicles or specific circumstances, a brake switch issue could lead to unexpected diagnostic trouble codes or issues, which is why a thorough diagnosis, often with the help of a professional mechanic or technician, is crucial to pinpoint the exact problem.

akkoeis wrote: ↑

Sun Oct 29, 2023 10:25 am

You also mentioned a specific situation where the C1142 code might be erroneously thrown due to a bad brake switch. It's possible that in some vehicles or specific circumstances, a brake switch issue could lead to unexpected diagnostic trouble codes or issues, which is why a thorough diagnosis, often with the help of a professional mechanic or technician, is crucial to pinpoint the exact problem.

I am a professional technician, a Nissan/ASE master tech in fact. P1574 has nothing to do with the brakes, it's a speed signal. Identifix has over 250,000 professional subscribers and none of them have ever heard of P1574 being caused by an Armada/QX56 brake switch either. No offense, but please don't spout when you don't know what you're talking about.

I never did figure out the problem. I didn't want to put any more money into it so, I wholesaled it to another dealer.