dbm7

'Did' work on them is more accurate ~ on the R31 Skyline forum, you can spot me as 'Solder'... I've written quite a bit about the 4R01 boxes there, and I ended up reverse-engineering the older TCU type operations, so we could fudge a custom TCU to pull off other tricks...and like all things, when you do it a lot, see the failure patterns, have to find parts etc etc, your head ends up filled with whys and wherefores... there was a reason Nissan went with these in more than 60models over 16+ years... all in all, the JR401E based design is an interesting study, as Nissan changed things over the years in a never ending battle against them lunching on themselves <grin>...by the time the RE4R01A rev.C came out (often referred to as RE4R01B), they'd more or less perfected the design...

I'll just reiterate that it's best to do all the wiring diagnostics, before even thinking about buying replacement solenoids ~ that is, be absolutely sure the solenoid is bad.....ie; bad connector(s), rodents chewed through a wire, etc etc. If you don't so this, you can fork out all the money for solenoids, only to find something else is wrong (this'll make you cry if you pull the valvebody only to find a broken wire is at fault... ...some more glue on the solenoid packs -- this is the RE5R01A shift solenoid assembly.... ...these are all shift solenoids ~ ostensibly they're the same as the shift solenoids from the 4-speed auto.... ...this is the RE4R01A solenoid set... ...with these, you have 3 shift solenoids attached to the plate, and the separate solenoid is the EPC solenoid (line pressure control) -- with both designs, the TC lockup clutch solenoid (also PWM so they could slide the clutch shut), is located on the lower valvebody half.... ...(story time)...back in the 90's, it was a common fault that the EPC solenoid (or TC-lock solenoid) would fail, but Nissan only sold them as part of the assembly (think ~$350 at the time) ~ thing was, Isuzu also used these boxes in light commercials, and you could buy the PWM solenoid as a separate part, so it was possible to buy/use that solenoid (around $65), and make it fit (remove the circlip, fit to old plate and deal with wiring)...making it a more cost effective repair. I've not seen the RE5R01A shift solenoid assembly, but with the 4-speed RE4R01A it was possible to hack/fit a single shift solenoid onto an other working set, using a donor solenoid from another set with failed EPC....(by rights the whole set should be replaced), but it ends up being a question of how much life is left in the box itself ; sometimes it's a viable repair to fix one solenoid, just to get another 100k of road miles out of it before it needs first overhaul...other times the box is that old/worn, you're as well doing first overhaul and replacing the solenoids and starting fresh... What Nissan did here with the 5-speed, was relocate the EPC solenoid to the lower valvebody (next to the TC lockup solenoid), and stuck the direct-drive clutch solenoid (for the extra gear) where the EPC solenoid used to be on the 4-speed....I can only imagine they did this for serviceability ; the PWM solenoids are most likely to fail, and it's a doddle to drop the pan and change these out (as opposed to dropping the valvebody itself to get at a top mounted EPC)... ...also keep in mind, that some BMW 3/5 series & Mazda (and maybe some Ford/Mazda rebadges, not sure), also used the RE5R01A box under a different name/part number...not saying parts availability is any better, but sometimes it helps to know this when it comes to NOS floating about in the EU.... HTH

That'd be right ~ the early RE5R01A is pretty much the same as the RE4R01A in many ways ; problem is they made lots more 4-speeds than 5-speeds.... I'm in AU, so you'll need apply the US supply scene... https://www.alltranz.com.au/shop/drivetrain/automatic-transmission/Mazda/RE5R01A/#scroll-electrical_components This'll give you the aftermarket parts listings -- you're looking for #56712 & #56713

And the rules change with time ...but speaking to the premise you raise here, some of us old farts will remember seeing every police motorbike with a rubber rear mudflap extension, fitted to the end of the rear mudguard. This was due to an ADR that required the rear mudguard to extend lower than the rear axle (iirc 15 degrees lower as measured at the axle center line)...it was changed in '89 updates, but basically before that date, any road going motorbike was technically 'illegal' (unroadworthy) ...the whole area is a real prickly pear... 😃

M'kay....that's the one (single wire unit is just for dash temp gauge as you say) ; auxiliary air regulator is worth checking, and EFI relay of course.

Check coolant temp sensor ~ symptoms fit the hard hot start/cold start OK scenario --- if sensor goes open circuit, ECU thinks engine is cold and enriches mixture ....works when engine cold, but floods them with rich mixture when hot (Hyundi MAP engines are a bit infamous for this)...

Those 2 solenoids in that assembly I mention, are the PWM solenoids for torque converter lock-up clutch & EPC (line pressure control) ~ when most folks hear of 'solenoid failure', the tendency is to think electrical failure...but fact of the matter is, especially wrt the EPC solenoid (which is moving/running all the time), you can have an electrically 'good' solenoid, that's absolutely broken/worn out mechanically inside...ie; valve plunger return spring rubbing against spring retainer plate, lowering preload pressure.. ...and the solenoid armature extension limit spring wafer with bad wear/broken off petals... ...and if there's ever been any metal flying about, damage to the valve plunger end itself... ...the stuff one never really sees, unless you go the whole 10yards trying to answer the question "why is my line pressure screwy, but TCU isn't flagging any EPC solenoid fault?"...and carefully dissect the solenoid. Worst (and most probable) scenario is when the plate spring petals break off, they get held by the magnetic flux, get mashed up by the armature into little bits, which end up in the space between the armature & shading core bore, and things get stuck or randomly jam up, and your line pressure goes flat and doesn't change...and the TCU never sees it, as it doesn't actively monitor LP... ..then it gets into insidious land, if you end up with lower than expected line pressure...lets say high clutch..and the lower pressure causes it to slip ~ when I say 'slip', think say 2000rpm on the drive plates, and 1800rpm on the driven plates, because the slip is making them under-rotate by 200rpm ; you get all the usual nasties like heat and band/clutch wear, but even if it's only 20rpm slip the same thing happens...and... you'll hardly ever pick this up driving the thing with the torque converter active as it effectively masks these sorts of slippages that are line pressure related ...(the newer TCUs can detect clutch slip rate)...just FYI as it were...

Ahh... it's an early RE5R01A box, that means the pinouts I gave are wrong (they were for the RE4R01A 4-speed box)... I'll have to dig around in my docs to see if I've got that schematic (they used the same gearbox plug, with the vacant pin wired to the direct drive clutch solenoid)...prolly hidden away in a supplement somewhere... ...there were 3 variants of the RE5R01A ~ this early schema was what we called the 'dumb' 5 speed ; it's what jatco called a 'medium duty' box, with torque holding up roughly ~200ft/lbs or so, which was good for NA from RB20/25DE and up to around VG30 output spec. With the RB25DET (and VG33/35 mills), the only options they had was the 4-speed 4AX00 box, which had been beefed up to handle the extra torque (primarily for the VG35, but it also suited the RB25DET mill and others)...and the RE4R03 box in large 4WDs a lot of the time... ...the next variant of 5-speed was redesigned, stronger, and 'smart'...first ones had external TCU with internal (on valvebody) Shift Control Unit, pressure switches, and 2 x TSS...and the last ones had internal TCU+SCU setup, with CANbus control etc etc. @DRoc81 On the RHS of the box towards the rear, there should be a stamped silver ID tag -- what's the model number? Oh...and with the early 5-speeds, the torque converter control solenoid assembly should be replaced as well (31940-60X00)...it's a bit Murphy's Law ....if one has failed, bet on the rest not being far behind ...

...just a note of warning, you shouldn't drive it about with the TCU in limp mode with only 3rd gear available ~ apart from the fact you end up sheering the ATF at the torque converter interface, the high clutch in these isn't especially the strongest, particularly bolted to the RB25DE mill...which is likely a 4AX01 box with lighter duty high clutch (the RB25DET got the bigger high clutch)...be careful out there...

...oops. forgot the TCU end...

...gearbox connector... CD06 -- solenoid A

If shift solenoid A is bad, that explains limp mode --- now you're in the same position as I mentioned previously, in that the next step is to confirm loom/wiring integrity from TCU to gearbox connector with a multimeter (the TCU cannot detect a broken wire, which can happen ..ie; rodent damage, loom rubbed through)...and then finally measure resistance (at the gearbox connector) for shift solenoid A ... ...once you confirm shift solenoid A is bad (open circuit, really low or greater than 40ohm resistance), then it's a job ; you have buy a complete solenoid set, get under the car and drop transmission oil pan, and remove valvebody assembly (the solenoids sit on top), replace solenoid set, and reassemble....it's not exactly a fun task, but readily doable.

Yeah, they're pretty dumb though...ie; they'll throw a solenoid error if the solenoid is dead, shorted, wiring is open circuit, or even if the driver transistor has failed (they can't self-diagnose much, they can only test inputs/outputs)... but if you wanted to try, I believe it's this protocol....(uses a long pulse indicator with short pulse counter)...

Yeah...I always start at the shift solenoids, because there's only a few reasons these will spook into limp mode, and bad shift solenoids is one ~ the other can be the shift control module (if you have steering wheel shift buttons)...it's easier to eliminate the solenoids first.

Aye, it has been pretty good since the shift ~ I just want access to the wiki ..again.. (now the mediawiki stuff has been updated), to get it all straightened out with consistent presentation (I talked to Session about it, turns out the mediawiki version was largely at fault..and pages created with older versions, etc etc)...I've basically given up asking, never get a reply...bit sad...but it is what it is.

From the OP's description, sounds to me like the TCU is in 'limp home' mode --- that is, no actuation power to shift solenoids, and the EPC valve is shut (full line pressure). This effectively sticks the box in 3rd gear, with as much line pressure as possible, to try hold the high clutch clamped shut....and so you get woeful acceleration and don't feel any shifts (because they're not happening). If you don't have Consult or some other scanner to interrogate the TCU itself, you can test with a multimeter to see if it's in limp home mode....ie; stick it in D with engine at idle (hold vehicle with hand/foot brake), and measure the voltage at the TCU feeding shift solenoids A & B -- both should be ON (battery voltage). If they are energized at the TCU, you can unplug the harness from the TCU, and check resistance down through the wiring to the solenoids themselves -- you should see about 20ohms on each coil --- if you do, you can presume the wiring to shift solenoids is OK -- if both measure open circuit, you have to check intermediate connectors in the loom down to the gearbox (and the gearbox connector itself), and check the shift solenoid resistance at the gearbox connector itself --- if the shift solenoids test open circuit here, problem is in the box (ether the solenoids or wiring to them is bad). If you get no voltage at TCU connector for the shift solenoids (and the solenoids/wiring test OK), check powers/grounds to the TCU itself --- if they're ok, it suggests the TCU is the culprit (and you'd need to interrogate it if possible, to find out why it's behaving badly)...

Just FTR, I see this morning the site is up again ~ dunno what was wrong, or if @niZmO_Man worked some magic (thanks if you did)...either way, good to see it back (although by the sounds of it, the future is undefined)...it almost makes me wonder if R31SkylineClub should be incorporated here somehow?... 😃

Sounds good ~ keep me posted

Oh...I have the electric mirrors as well iirc ...they're in the same state as just about every other R31 door mirrors, with the 3 plastic screw towers broken/cracked in the plastic molding. All the interior is 'dry', so the mirror switches etc likely all work fine. Some pics below of the trimmer pieces ~ looks to me like previous owner, painted chrome finished trims with black paint ...ergo, the chrome underneath is likely a-ok... ...starts to look yukky posting stuff like this, how much did it cost in fuel on your last sortie up this way?...me just thinking aloud, borrow someone else's 4cyl to cut costs, come do your own pick'n'pull like before to save me some bother...hehe.. but whatever, I'll just earmark bits I know you want, because the way this is all panning out, I'll be able to retire the R31 from daily duty at long last, replacing it with a Subaru wagon I'm lining up in the wings...ergo, my attitude towards the donor pinny shell is starting to wane a bit, and I'm more than happy to help you out there... Like you say though, no rush...and I'll guarantee we won't be moving too far from this locale at any rate 😎

Yep, all good ~ the spare AC fan here, I think has a dead armature segment (I didn't pull it apart to verify, as there's plenty of AC fans out there that can be fitted to the R31)...I'll get some pics of the exterior trim pieces...

Ahh right, I did offer to help, but been a bit lax wrt donations...sigh... perhaps the roller door has finally run down...

..could be worse... but out here, renting private affords some luxuries ...we've even been told the Sept dateline isn't critical, and I'd rather move stuff in the cool of winter, than slogging it out in the heat. Recall we were talking about the million dollar view this place has?...that's what he got for it... (won't be so nice when the quarry happens at the back in the future...lol..)... ...cool, I'll stick the wiper motor in a wee box...umm.... the pinny is GLX trim ~ I think that's about as close as it gets to Silo spec when it comes to the S2 pinny...ie; electric mirrors etc etc...dunno about the trip computer/wiring...I do electronics repair, I'd be willing to take a look at it for you. As you saw, all the dash is there in that car..and thinking about it, it'd be easier to pull the whole center section out, rather than just the ashtray and rails, but your call...

Just got back from a week away out west, and it seems the R31 forum isn't responding ~ I know there's a lot of AI/bot scraping causing problems on da'net at the moment, so dunno what's going on. I'm actually more concerned about another member on there, I've been trying to help rebuild his automatic box... no idea where he's up to in the build, frustrating, a bit it is.... Anyone got any news?

Howdy ~ got that wiper motor out, all good ....also, replied to your post in the R31forum wrt ashtray and rails ...but I've been away for a week, and getting home, that site's not responding, so posting here for FYI... ...also, our mate sold this place last week (that was a surprise to come home to), so we've got until Sept. or so to move out ~ needless to say, if you want any other bits off that R31 pinny donor, now's the time to claim them 😃 Good to see that carpet piece finding a home...that was a bit of a score 😎

Steering rack might be full of water, same with gearbag....