paradiddle

I have no speedo, ATC lamp flashes, ABS lamp is on. I pull code and get a U1001. I have read that this is a short or a ground problem from ECU. I checked ECU ground inside car and did a reconnect harness. Under the hood I have looked for any obvious wire issues from firewall out. checked battery and connections and re did ground connector next to battery to fuse box.

DennisMik

iTrader: (2)

Here is what I found when searching for the U1001 code:

The U1000 and U1001 mean that there is no communication between the engine control unit and another control units that are part of the CAN system (Controller Area Network) or that at some point there was no communication. Before do any repairs with the U1000 and U1001 codes, the factory recommend repairing any other problems in the car.

Were there any other code besides this one?

knight_yyz

iTrader: (40)

If there is no communication he won't be able to grab any codes.

Also check the grounds under the engine cover. There is a small cluster there on the passenger side

paradiddle

My Innova code reader shows multiple codes - up to 7 with the U1001. My cursor down button doesn't seem to be working anymore so all I see is the first code and I can erase. the u1001 comes right back. After a cold start everything is fine. After 10-15 mins I get ABS and TCS off lamps and speed drops off. I do not get chk engine even though I show codes. The AT flashes with key on after 10 mins. but not while running.

I have checked the battery and connections. I redid the ground cluster next to battery near fuse box on drivers side. I reconnected the ECU cable and re clamped one of the mounting screws for the ECU.

I will look at those other grounds including the passenger side,

DennisMik

iTrader: (2)

As strange as it sounds, you can still maybe read the Pxxxx codes. The info I read refers to "control units" and the no communications may be happening with only one of these things, whatever they are.

I also found references to a service bulletin about this, TSB02-002, but I couldn't find it.

paradiddle

I do understand that one of the codes may be the source of the problem but I don't know why it would continue to kick other codes unless the logic is related.

I may have to get another code reader to see the other codes and will work on grounds. No one seems to mention the ECU being a problem. One person on another Nissan forum replaced his battery even though it would start and that fixed it.

knight_yyz

iTrader: (40)

According to the FSM , if you have TCS you should remove the ECU and the TCM from the vehicle and perform a resistance test.

ECM terminal 109-113 and TCM 5-6 should both show a resistance of 108-132 Ohms. If these are not in range replace the unit or have it repaired.

Brudface

Go and search this---- No speedo, No Odometer, ABS/TCS Bosch
brings you to exactly what your problem is i have had this issue for more that a monh or two and trust me... TORE everything apart... did everything according to the FSM with codes P1212 AND U1001--- now try this--- go to the brake section of the FSM and try testing your ABS module exactly the way it says... I failed the FIRST one and trust me wasnt too pleased when I phoned the dealer and they told me I can't just buy the module, i have to buy the whole pump... after pretty much politely telling them to go EFF themselves, jumped on-line and bought a used one about an hour away and will have it in my hands on tuesday for 125, pump AND module.... EAT that $hit Hunt Club Nissan

paradiddle

Ok, on cold start no problems.
after 10 mins no speedo , abs light, TCS light
u1001 and p1212 (abs) codes

I drive the car and get an additional p1574 (speed sensor related)

I have read the Bosch ABS stuff for other vehicles and solder breaks are common. But I don't know why I get a P1574.

I have googled same code combos and I get AT transmission connector problem, short between IPDM and ABS, as more stuff to chk.

Brudface

mine too I get the same thing, cold start ZERO problem... but still getting the at check light blinking at me on coldstart... after about 5-10 minutes of driving speedo, odo stop working, then the abs light and tcs off light kicks on... i would pull the codes the first couple of days this started happening getting 4 codes.. U1001, P1212, P1574, and P0500... at first I started doing everything that would've been the cheaper fix, pulling pretty much all connectors off, cleaning them then re-seating them with di-electric grease... after that did absolutely jack $hit, i decided to redo- every ground under the hood... that did nothing... Checked all of my wheel speed sensor, and they all checked in spec... Moved into the cabin had my entire car in pieces on my lawn re-did the grounds in the cabin... Still nothing, which SUCKED!!! After feeling terribly defeated pulled out the fsm, checked every single step for the P1212 code, then rechecked it... nothing... absolutely stumped decided to do the test for a bad ABS/TCS module, step one power is good, step two fail, step three fail, step four fail... fml... I was like after doing EVERY single thing hoping it would be a cheap fix it DEFINITELY isn't.

paradiddle

Tonights codes - including yesterday
u1001, p1212,p1574,p0021 (odd one), p0500, p1212, U1001,P1574,P0021

Pulled and checked the trans connectors and looked at all the grounds I could find via the EC. I guess ABS is next. Did you get a used module for TCS ?

I did find a service that repairs these. http://www.cheapabs.com/vrnissan.html

Were you able to pull the module off without pulling the whole unit? - looks tight in there but I will use all my flex joints.


************************************

update - Its too tight in there to get all those torx screws off. I will have to pull the whole unit.

Brudface

After some serious patience I WAS able to get the module off the pump without pulling the stupid thing off... there were curse word exchanged between it and I... it was way easier to get on... used the torx bit and a small ratchet... YES it's tight, but it is doable... you have to disconnect the module, take out the entire air filter assembly, and move the harness out of the way. after putting it back on and forgetting to connect my mafs, it started like $hit and I was like that is more than likely not good... anyways ended up connecting everything and finally turned the key to the on position, NO count them NO stupid blinking AT check light... the ABS light, TCS off light, and SES light were still on... cleared all codes which got rid of the SES light... re-scanned it no codes, SWEET... ABS light and TCS light were still on i was like NOOOOOOOOOOOOO. Took it for a ride Speedo worked and another 50 ft and the lights all turned off... done and done

And YES paradiddle i actually got a used pump AND module 125 sourced locally.

paradiddle

I got it out like you did and am now sending it off to Cheap-ABS for a repair.
I had to make a narrow t-20 torx setup but it worked

Brudface

LOL, of course they had to put it on the backside of the pump eh... Such a dumb design... They should be able to repair it, I don't know what area your in but the 5.4 bosch unit is in a whole whack of cars and they all have the same harness, I'm surprised you couldn't find a used one. I tried to take my old one apart and to be honest with you I couldn't so I just chucked it. Good Luck with the repair and I hope they can repair it.

paradiddle

all fixed - thanks to Cheap ABS ($109) and Brudface for his perseverance. This is another goes to show you that not all codes lead to the problem. This was an easy fix with knowledge. If not I would have gone done brudfaces original path....

channoff

This thread is a life saver. I too am sending mine to Cheap ABS. I haven't started removing pump and control unit yet. Any pointers that you can give me? Also, about how long did it take to remove everything?

DjHackStyle

Amazing, but in the end you went through the FSM that lead u to understand the ABS module was bad. This is what this forum is for, enthusiasts sharing information, Im happy to be part of this forum

paradiddle

I had to make a narrow t-20 torx setup but it worked

channoff

I hope to remove this over the weekend. Can you explain how you did that? I have a narrow flexdriver that will hold a t-20, but my gut feeling is that it won't flex enough to work.

channoff

I just posted my basic write-up to remove the ABS module on another thread. Here it is again for those who need it.

Steps for removing ABS Module:
1) ABS module is located just under brake master cylinder and attached to the ABS pump. To access, remove entire intake/MAF section. 5 bolts that remove with phillips head screwdriver

2) The worst part. There are 6 torx-20 bolts facing towards the wheel well and that are very very hard to access. The top 2 aren't bad, but there is almost no working space for the other 4. I had to use multiple combinations of flex drivers, wrenches, etc to get those out. Probably took me over two hours for this part, but will probably only take 20 minutes in reverse now that I know which combinations work.

Good luck on this part, just know that it IS possible to get those torx out.

3) You're almost done. There are two electrical connections on the bottom of the ABS module. First, unhook the large one by grabbing the pull tab that faces towards the front of the car near the very bottom of the module. Slide towards front of car maybe 2" or so.

Once that is out you can maneuver the module enough to access the smaller connection on very bottom of the module. That one pops off easily with a flathead screwdriver.

And that's it. Sounds easy, right? And it is, but those torx screws are not your friends.

malachi

Thanks for this. I have both the P1212 and U1001 codes on an '02 model and will attempt this repair over the weekend.
I have no worries about getting the part out. I glanced down at the area today and wondered why you didn't just pull the pump block off the car and give yourself a bunch more room? Just tweak the valve body over, and room should not be an issue.

The car only has 2 other codes for O2 sensors. And a leaky radiator.

The only one I can find locally is from a 2001 model? I have a feeling that it will not be compatible with the 02.... wasn't there a revamp of the cars between years?

oswernlaulin

Thank to you all. Excellent information.

Child_uv_KoRn

iTrader: (7)

Fail. Nice try, though. You'll get to 20 posts eventually!