Range Rovers Forum banner

Information on ZF 5HP24 output speed sensor for forum member drm

36K views 9 replies 5 participants last post by  mrjpw  
#1 ·
Information on ZF 5HP24 output speed sensor for forum member drm

Forum member drm has asked if I can provide some guidance on how to check for a fault with the transmission output speed sensor & circuit for the ZF 5HP24 transmission (‘02–‘05MY petrol models).

While checking the output speed sensor & wiring I suggest you carry out the same function tests for the input speed sensor (they’re identical parts – p/n STC4444) at the same time to provide a comparative set of readings. All that can be easily checked is the internal winding resistance of the speed sensor itself, and not its actual function, but this can then be used to test the continuity of the transmission wiring harness and the main external harness (which is part of the engine wiring loom).

Once the transmission sump pan is off you can remove the single Torx 27 screw & bracket which holds the sensor in position and remove the 2 pin plug.

Image


If you then measure the resistance directly across the two pins of the speed sensor you should get a reading of between 285 Ohm & 365 Ohm (at 20 deg. C)

Image


To check the transmission wiring harness, replace the sensor and then you should be able to measure the same resistance at the multi-connector plug on the rear of the casing by measuring between pins 1 & 10 (or between pins 5 & 6 in the case of the input speed sensor)

Image


Image

 
#2 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

To check the wiring right back to the ECU take the resistance reading between pins 3 & 13 of the plug which has the most wires connected to it of the three (input speed sensor is pins 23 & 33)

Image


Image


Image

Phil
 
#3 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

fantastic piece of information, i have checked the wiring down to the multi-pin connector and it is showing an open circuit in the gearbox, all i have to do now, is drop the sump (when the rain gives up) and check the wiring and sensor. Hopefully, it will need a new sensor or a repair to the cable- a long way from the £3500 the stealer wanted for a new box. For anyone else reading this that has a problem, i will give a quick outline of my problem, hopefully it may be of use to others!
Had no probs at all then suddenly went into 'trans fail safe'. each time i switched off and restarted it would be OK. Every time i drove off and reached 10/12mph (presumably when the sensors, ecu,etc kicked in) it would go into 'fail safe'. I tried it rolling down a hill without accelerating, freewheeling down a hill in neutral and even reversing-each time it would go into 'fail safe' this, i believe, eliminated the usual cause of a seal failure allowing oil to seap onto clutch A as clutch A is not used in Neutral or Reverse. Because it went into 'fail safe' each time at 10/12mph and not when it is hot etc.etc i did not think it was the gearbox and the Master-RRPhil- confirmed it for me. Hope this may help others and give a little hope!! I will update this when i hopefully find the cause of the problem!
Regards,
Drm
 
#10 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

fantastic piece of information, i have checked the wiring down to the multi-pin connector and it is showing an open circuit in the gearbox, all i have to do now, is drop the sump (when the rain gives up) and check the wiring and sensor. Hopefully, it will need a new sensor or a repair to the cable- a long way from the £3500 the stealer wanted for a new box. For anyone else reading this that has a problem, i will give a quick outline of my problem, hopefully it may be of use to others!
Had no probs at all then suddenly went into 'trans fail safe'. each time i switched off and restarted it would be OK. Every time i drove off and reached 10/12mph (presumably when the sensors, ecu,etc kicked in) it would go into 'fail safe'. I tried it rolling down a hill without accelerating, freewheeling down a hill in neutral and even reversing-each time it would go into 'fail safe' this, i believe, eliminated the usual cause of a seal failure allowing oil to seap onto clutch A as clutch A is not used in Neutral or Reverse. Because it went into 'fail safe' each time at 10/12mph and not when it is hot etc.etc i did not think it was the gearbox and the Master-RRPhil- confirmed it for me. Hope this may help others and give a little hope!! I will update this when i hopefully find the cause of the problem!
Regards,
Drm

Hi mate, was your gearbox slipping between gears, i.e 1st. 2nd 3rd when it went into fail safe mode? Thanks
 
#4 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

Finally got round to taking the sump off and found the output speed sensor is at fault- it looks like the end has exploded!! I'm hoping it's not something more serious and a piece of debris has got caught between the sensor ring and sensor ripping it off, what would the chance of that be!?
I've managed to drag the bulk of the sensor internal wiring out of the box but no doubt there will be bits floating around, hopefully a few flushes will get the rest and a few strands of thin copper wire will not cause too much prob!!
There was a fair bit of debris in the sump but that could be the sensor. I've oerdered a new sensor so i will see how it goes when i fit it.
 
#6 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

Well, managed to get round to fitting the new sensor, replaced sump and old oil - Hey, Presto!! Everything working fine, no probs at all. I will now flush/renew the filter and oil.
Why is it nothing can be done about main dealers ripping us off? I do not believe that there diagnostic equipment would not show sensor not working, when i've been to the local specialist, I think their machine can tell you how many sugars you have in your tea-it's that good!!
If you are struggling to refill the gearbox anytime, i can recommend a Laser multi-purpose mini pump-code 04021 4385 £18 from machinemart, holds a litre at a time. makes it so easy.
I have also ordered my mobil oil from Opie oils, cheapest i could find and it gave 25% off when i entered an old offer code- CLEARANCE

Part Nos if required-
Sensor STC444, Oil Screen(filter) LPW000030, Oil Ring TYX000100, Sump Gasket TYF000110, Drain plug UYP000070, Level/filler Plug LR007607
 
#9 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

Well, managed to get round to fitting the new sensor, replaced sump and old oil - Hey, Presto!! Everything working fine, no probs at all. I will now flush/renew the filter and oil.
Why is it nothing can be done about main dealers ripping us off? I do not believe that there diagnostic equipment would not show sensor not working, when i've been to the local specialist, I think their machine can tell you how many sugars you have in your tea-it's that good!!
If you are struggling to refill the gearbox anytime, i can recommend a Laser multi-purpose mini pump-code 04021 4385 £18 from machinemart, holds a litre at a time. makes it so easy.
I have also ordered my mobil oil from Opie oils, cheapest i could find and it gave 25% off when i entered an old offer code- CLEARANCE

Part Nos if required-
Sensor STC444, Oil Screen(filter) LPW000030, Oil Ring TYX000100, Sump Gasket TYF000110, Drain plug UYP000070, Level/filler Plug LR007607


Hi mate, was your RR going into Trans fail safe prog mode prior to changing the input/turbine sensor?. Mine slips and then dumps itself into safe mode, i.e 4th gear. It happens even when ive been driving for 2 mins. Thanks for your time​

 
#7 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

I've heard mix reviews about touching the RR's transmission, especially when doing a flush on it. But I'm curious to know how many quarts are needed to properly refil the transmission to its exact level of fluid, when simply draining it out and replacing the filter, not an actual complete flush? Anyone out there know the exact amount because I've heard it's anywhere from 7-9 quarts. Thanks once again.
 
#8 ·
Re: Information on ZF 5HP24 output speed sensor for forum member drm

Hi mate, was your RR going into Trans fail safe prog mode prior to changing the input/turbine sensor?. Mine slips and then dumps itself into safe mode, i.e 4th gear. It happens even when ive been driving for 2 mins. Thanks for your time