Freelander auto gearbox jumping from high gear to 2nd when warm

For peeps reading this int future and wondering about where the solenoids are and what to eggspect when the cover comes oft:


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Once again, thanks for your reply.

I guess Rather than trying to remove the cables from the box, I could do a continuity test from pin to pin at the barrel connector while wiggling the wires where the outer casing is frayed. I've made up a couple of wires with female pins and insulated the outside with a little heat shrink so I can plug them in individually at the gearbox side of the barrel connector and plug them into my multimeter with the audio 'beep' set for continuity. This should leave my hands free for wiggling wires

I would test with the wires left inside the auto case if it we're mine. Saves hassle of getting them in/out if there is any.

One thing to note if using the diode check bleep on a meter it normally bleeps for 10 or 20 ohms and below depending on the meter. If one were 15ohms and the rest 1 then yer wouldn't know. I find it betterer to check ont resistance setting to see the value.

Hi again.

I changed the reduction timing solenoid as you suggested (in addition to the 2/4 brake duty and the line pressure duty solenoids).

I also checked the wiring loom while waggling the noticeable area of wear but all seemed OK.

I reassembled everything and topped up the AT fluid. I lost about 1 litre of fluid who I removed the solenoid cover, so I put 1 litre of new fluid back in before getting the box up to temp and working through each gear. I then removed the drain plug. I think I was supposed to do this with the engine running. I actually removed the plug with the engine off. When I removed the drain plug, about 2 litres of fluid drained off. Hmmm... Was it important to keep the engine running or was my gearbox overfilled by the previous owner/serviced? Should I be concerned?

Anyway, I took the car for a drive for half an hour. Nothing over 60kph, quite a warm day (heading for 39 deg C today and 44 deg tomorrow!) I think I need to move to the UK again The car performed normally. I have no idea if the problem is fixed. Only time will tell, I guess.

Once again, thanks for your help. I'll keep you posted.

Tony

The jatco auto oil level should be checked with the engine running on tickover. If you check it with the engine off, the pump won't be pumping and the fluid level will rise above where it would be if the pump was running. Hence more oil will come out of the level plug than expected. The result is your auto oil level is too low and you risk damaging it. Don't drive it like this. Get some more oil and set the level correctly. Hopefully yer won't have caused any damage but yer never know until it starts playing up. Instructions in post 48 in the fred below:

https://www.landyzone.co.uk/land-rover/jatco-automatic-gearbox.69336/page-3

Hi, I sorted the oil level and have now driven the car for about 4 hrs in total. So far so good.

Good news. Keep us updated if keeps going ok.

Just a quick update. I've been driving the car for 8 weeks or so since swapping the solenoids with no problems.

Not so fast. I have noticed that all is not completely well. The remaining symptom is that on shifting from 2nd to 3rd the gearbox (very occaisonally) over-revs on disengaging 2nd and then changes harshly into 3rd. It is possible that one of the solenoids I previously replaced was not OK (2nd hand) or that I should have replaced more than the three I did: reduction timing solenoid, 2/4 brake duty and the line pressure duty solenoid.

I'm suspecting Shift Solenoid A Great resource for this gearbox in the attached file.

What attached file?

I found this fred recently when looking through older posts to see if peeps came back with results. I thought about asking if it was still ok but didn't want to jinx it...

Solenoid A is the only shift solenoid (out of 3) that changes when you change from 2nd to 3rd gear, which would point towards this being the cause. The best and only way to diagnose the Jatco for faults like this is to follow what the main dealers do. Check all resistances when the auto is cold as per the link earlier in this fred. Also make sure the fluid level is correct by following the correct procedure. The resistance check doesn't always provide an answer but it gives you a datum to work off.

I changed Shift solenoid A but unfortunately, I may have been mistaken because it is occaisonally 'flaring' on shifting from 3rd to 4th.

OK, so I changed all the gear solenoids for new ones. The 2-3 shift is very slightly unsmooth. However, I now sometimes go into limp home (F4) mode when the gearbox is cold. I have had the codes read and it show that ratio 2 and ratio 3 are out of range. The mechanic who read the codes said that he also believes the viscous coupler has locked up. First of all, is it possible that the viscous coupler failure could contribute to either the slightly unsmooth gearchange and/or the 'out of range' error? Is it new gearbox time?

I'd say its time to do a 1 wheel up test (and check the tyres while you're at it)...

https://www.landyzone.co.uk/land-rover/tests-new-freelander-owners-should-do-on-their-car.312863/

I should imagine the mechanic that told you this was just clutching at straws and didn't really know whether the VCU was faulty or not and didn't really know how the VCU could impact the auto box. I'm pretty sure it can not throw an F4. F4 is mentioned quite a bit on here and I don't recall any possibility of the VCU causing it.

However, if you haven't done a 1WUT, its worth doing to protect other parts of the transmission.

TonyOZ said:

OK, so I changed all the gear solenoids for new ones. The 2-3 shift is very slightly unsmooth. However, I now sometimes go into limp home (F4) mode when the gearbox is cold. I have had the codes read and it show that ratio 2 and ratio 3 are out of range. The mechanic who read the codes said that he also believes the viscous coupler has locked up. First of all, is it possible that the viscous coupler failure could contribute to either the slightly unsmooth gearchange and/or the 'out of range' error? Is it new gearbox time?

Click to expand...

vcu viscous coupling unit has nothing to do with F4 flashing

what does the resistance test results say... anything measured out of range?

check error codes in the engine and auto compuer, clear them both then take it for a drive. it's worth having a look in the abs anorl for errors.

When he say's "viscous coupler" does he mean torque converter I wonder

I've done the one wheel up test and the VCU allows the single wheel to move.

Since then, I have been driving the car regularly and the symptoms can be replicated reliably and consistently. Always better than an intermittent fault! When the car is driven away from cold ( by cold I mean Australian cold so 20 deg C or so) the gearbox will not shift from first and then will enter 4th with F4. When I let the car warm up to the point where the coolant temp gauge needle has risen above the bottom mark on the gauge before driving away the gearbox shifts normally. The last time I had the codes read they showed P0732 2nd gear ratio out of range and P0733 3rd gear ratio out of range.

My plan now is to check the resistance readings for the speed sensors when cold.

So I checked the speed sensor and temperature sensor resistances at the ecu and the barrel connector. The speed sensor values were:
Vehicle speed sensor 570ohm
Intermediate speed sensor 566ohm
Turbine speed sensor 561 ohm

All at 20 deg C

However, the fluid temperature sensor showed complete resistance at both ecu and barrel connector. So, I guess I have a loose or broken wire somewhere or a failed sensor.

Could this explain why my electric fan often runs after shutting down even after running for only a minute or two?

TonyOZ said:

...
However, the fluid temperature sensor showed complete resistance at both ecu and barrel connector. So, I guess I have a loose or broken wire somewhere or a failed sensor.
...

Click to expand...

What does yer mean by complete? Is yer meter reading a very high, low or open circuit resistance? Some meters read OL for over load which is open circuit.

Failed temp sensor is a problem unfortunatley

Meter reads 1 as it would for example with a broken wire.

TonyOZ said:

Meter reads 1 as it would for example with a broken wire.

Click to expand...

Ouch. At least you have a known fault to look into.