P38 02 Thor Brake & EAS

I entered the values as per his video. I've seen these posted on here. Irish rover I think. Perhaps the values were examples only for purposes of tuition. High Fnts 154 Rrs 135; STD. Fnts123 Rrs 109; low Fnts 107 Rrs 97; access Fnt80 Rrs 75. I understand these are but digital representatives and real values have to be related in inches/centimeters . I'll go and get the values from Lzone . Thanks for a constructive response. I'll go "like" now.

You can't just put someone else's readings in. All sensors will read differently.
You need to put the axle to a known position relative to the chassis then read what the sensors are reading and check that they are 10 or more points away from the top or bottom limit of what's acceptable and also that they are within 5 points, especially at the front.
If they are not within these parameters it will cause problems.
Once you have these known fixed position values, you can write them to the ECU as its target height for the future.
Measuring to the arches isn't a great way of doing it. A set of setting blocks is a 5 minute job and 5 quid from b&q

Grrrrrr said:

Interesting. So the wiring change in the later GEMS essentially brought them into line with the diesel and THOR setup.

Click to expand...

Pretty much, yes. I know I sat down and worked it all out ages ago as to which unit was for which VIN ranges of P38 (originally) and which versions superceded etc, so dug it out and it's below:



I collated all that info from a parts tree on one of the many websites that have them - For reference, VIN XA410482 was the GEMS/Thor changeover VIN...

It's all a bit of mess and craziness! But superceded part numbers seem to be backward compatible (I.E. a JFC102550 unit will work on anything all the way back to AWR1012 vehicles with the AC/front screen/front heated seats options)... but they're not forward compatible, at least pre/post XA411503 which is where the wiring modification was done to have the compressor relay in the fuse box, like the Thor models had as standard.

My general rule of thumb is that if it's an AWR1012/5051 then it will work ok in the older versions that didn't have the updated wiring, as it monitors the compressor output feed for a load, and will throw an error if it doesn't detect enough of a load (IE just driving a relay coil), so it isn't suitable for the later vehicles, and will throw the chequebook fault all the time. A JFCxxxxxx unit will run the later vehicles with the wiring upgrade, and relay in the fuse box. they will also run the earlier versions, as it looks like they kept the MOSFET that drives the compresor clutch directly in the earlier models (so it's capable of handling the current) but just wrote out of the firmware to throw a fault if it didn't detect enough load - so it wouldn't throw a wobbly when just turning on a relay.

The JFC units will run the older ones, because as I mentioned above, they kept the MOSFET, so they are capable of driving the compressor clutch, so won't burn out of anything silly like that.

To bring it back on - topic, as I've digressed a bit... with the OP having an '02 model - it would have come with JFC102550 from the factory, and if it's got the AWR5051 unit in it, then it WILL always throw a fault as it's expecting to drive the compressor clutch directly, rather than just a relay in the fuse box...

Marty, you're a bl**dy marvel.

This thread should be carved in stone. I'm the local rung up "just a quickie" . The question might be quick but what generally happens is I'm drained of knowledge obtained usually painfully and over time. I then hear nothing. For knowledge to be made public as you guys have done so generously deserves a bit more than a "like". The penny's dropped on the EAS thing and I've had what amounts to one to one tuition on P38 Air Con. I guarentee you won't hear nothing after I've applied my new found knowledge. I'll, at least have the courtesy and consideration to post the outcomes. But then, of course, stay by the phone for my next disaster. Very best regards. Peter.
Guess what. Matron's calling.

Bed bath time, eh?

This is a purely academic question. Having recharged my AC and not surprisingly the compressor didn't kick in with the wrong control panel, the system was duly discharged. I put my original control box back, faults and all, and even with the system empty of refrigerant the compressor clutch kicked in firing the compressor up. It kicked out again after "no aircon" was pressed. Would this be expected? BTW. Got amazing service on a replacement control panel yesterday. I'm not allowed to advertise here so I won't. If anyone can guess from whom, answers on a postcard. Regards and thanks all. P.

supapete said:

This is a purely academic question. Having recharged my AC and not surprisingly the compressor didn't kick in with the wrong control panel, the system was duly discharged. I put my original control box back, faults and all, and even with the system empty of refrigerant the compressor clutch kicked in firing the compressor up. It kicked out again after "no aircon" was pressed. Would this be expected? BTW. Got amazing service on a replacement control panel yesterday. I'm not allowed to advertise here so I won't. If anyone can guess from whom, answers on a postcard. Regards and thanks all. P.

Click to expand...

The compressor should NOT start if there is no refrigerant pressure. Do NOT do it the system will be damaged. The dual pressure switch controls it. Position 1 less than 1.2 bar. No power to compressor from fuse 27. Position 2 above 30 bar. No power to compressor from fuse 27. Position 3 from 2.1 bar to 21 bar. Power to compressor from fuse 27. Only in position 3 on pressure switch should there be continuity pin 1 to pin 2 and the compressor be powered and run. I would suggest the pressure switch is knackered.

On its way as we speak. Both aforementioned culprits. Marty's post was more than graphic and I understood it. But there's always something else I can't see, which is why I enquired. Do you ever sleep? You'd be welcome, I'm sure, at one of our group therapy sessions. I'll ask Matron. Thanks again. Now for the ol like button. P.

martyuk said:

Pretty much, yes. I know I sat down and worked it all out ages ago as to which unit was for which VIN ranges of P38 (originally) and which versions superceded etc, so dug it out and it's below:

I collated all that info from a parts tree on one of the many websites that have them - For reference, VIN XA410482 was the GEMS/Thor changeover VIN...

It's all a bit of mess and craziness! But superceded part numbers seem to be backward compatible (I.E. a JFC102550 unit will work on anything all the way back to AWR1012 vehicles with the AC/front screen/front heated seats options)... but they're not forward compatible, at least pre/post XA411503 which is where the wiring modification was done to have the compressor relay in the fuse box, like the Thor models had as standard.

My general rule of thumb is that if it's an AWR1012/5051 then it will work ok in the older versions that didn't have the updated wiring, as it monitors the compressor output feed for a load, and will throw an error if it doesn't detect enough of a load (IE just driving a relay coil), so it isn't suitable for the later vehicles, and will throw the chequebook fault all the time. A JFCxxxxxx unit will run the later vehicles with the wiring upgrade, and relay in the fuse box. they will also run the earlier versions, as it looks like they kept the MOSFET that drives the compresor clutch directly in the earlier models (so it's capable of handling the current) but just wrote out of the firmware to throw a fault if it didn't detect enough load - so it wouldn't throw a wobbly when just turning on a relay.

The JFC units will run the older ones, because as I mentioned above, they kept the MOSFET, so they are capable of driving the compressor clutch, so won't burn out of anything silly like that.

To bring it back on - topic, as I've digressed a bit... with the OP having an '02 model - it would have come with JFC102550 from the factory, and if it's got the AWR5051 unit in it, then it WILL always throw a fault as it's expecting to drive the compressor clutch directly, rather than just a relay in the fuse box...

Click to expand...

I think this information should be posted in the Technical section under HEVAC information as it is most informative and accurate

ovalandrover said:

I think this information should be posted in the Technical section under HEVAC information as it is most informative and accurate

Click to expand...

That'd require some like @blue beasty or possibly @ratty.

wammers said:

The compressor should NOT start if there is no refrigerant pressure. Do NOT do it the system will be damaged. The dual pressure switch controls it. Position 1 less than 1.2 bar. No power to compressor from fuse 27. Position 2 above 30 bar. No power to compressor from fuse 27. Position 3 from 2.1 bar to 21 bar. Power to compressor from fuse 27. Only in position 3 on pressure switch should there be continuity pin 1 to pin 2 and the compressor be powered and run. I would suggest the pressure switch is knackered.

Click to expand...

Did he not say they'd filled it with Nitrogen at some stage? Or was that another post?

ovalandrover said:

I think this information should be posted in the Technical section under HEVAC information as it is most informative and accurate

Click to expand...

Just the post you quoted? With what title?

blue beasty said:

Just the post you quoted? With what title?

Click to expand...

The one below from Marty. Title had better be something like: HEVAC part-number to VIN mapping.

martyuk said:

Pretty much, yes. I know I sat down and worked it all out ages ago as to which unit was for which VIN ranges of P38 (originally) and which versions superceded etc, so dug it out and it's below:

I collated all that info from a parts tree on one of the many websites that have them - For reference, VIN XA410482 was the GEMS/Thor changeover VIN...

It's all a bit of mess and craziness! But superceded part numbers seem to be backward compatible (I.E. a JFC102550 unit will work on anything all the way back to AWR1012 vehicles with the AC/front screen/front heated seats options)... but they're not forward compatible, at least pre/post XA411503 which is where the wiring modification was done to have the compressor relay in the fuse box, like the Thor models had as standard.

My general rule of thumb is that if it's an AWR1012/5051 then it will work ok in the older versions that didn't have the updated wiring, as it monitors the compressor output feed for a load, and will throw an error if it doesn't detect enough of a load (IE just driving a relay coil), so it isn't suitable for the later vehicles, and will throw the chequebook fault all the time. A JFCxxxxxx unit will run the later vehicles with the wiring upgrade, and relay in the fuse box. they will also run the earlier versions, as it looks like they kept the MOSFET that drives the compresor clutch directly in the earlier models (so it's capable of handling the current) but just wrote out of the firmware to throw a fault if it didn't detect enough load - so it wouldn't throw a wobbly when just turning on a relay.

The JFC units will run the older ones, because as I mentioned above, they kept the MOSFET, so they are capable of driving the compressor clutch, so won't burn out of anything silly like that.

To bring it back on - topic, as I've digressed a bit... with the OP having an '02 model - it would have come with JFC102550 from the factory, and if it's got the AWR5051 unit in it, then it WILL always throw a fault as it's expecting to drive the compressor clutch directly, rather than just a relay in the fuse box...

Click to expand...

Grrrrrr said:

Did he not say they'd filled it with Nitrogen at some stage? Or was that another post?

Click to expand...

No he said to test the compressor they would only fill it with Nitrogen. Normally refilling is done with engine running and aircon turned on, at some stage compressor should chime in. Fill is then continued until the system has the correct amount of gas in it.

Mornin' all. In conclusion, yeh right. 1)Got the HEVAC up and running no faults' thanks to an understanding here. Blend motors replaced; both pressure switches; renewed O rings to evaporator after taking it out and ultra violet checking for leaks; renewed control panel WITHOUT disconnecting battery hence DT's everywhere and engine not firing up; renewed drier; replaced heater matrix; replaced condensor and plumbing last year. 2)ABS. replumbed rear brakes and bled in accordance with the gospel and help here. No faults 3)EAS. Replumbed dodgy airlines around and over rear chassis and subframe. Replaced rear airbags; O rings, diaphram and pressure switch to valveblock. Got EAS unlock to fly correctly (get latest download) and experimented with height settings thanks to an understanding here. The simple reason I've posted this tedious rendition is to let you all know that the trouble you've taken to help and educate me hasn't fallen on stoney ground. I'm now going "like" button crazy. As you, no doubt, are aware this isn't the end of the story. I'm about to post a new thread as my query would muddy this most informative thread. Very best regards and thanks again. Peter.