UnitLandy
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Sadly, I don't have him anymore but new Daleks are in the pipeline...
P38A Height Sensor replacement
- Thread starter J L Carr
- Start date
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Measure the resistance at the height sensor. Then re-connect, and measure the same wires at the ECU. There will be small differences, but any open circuit wires should show up. Then decide whether the take seats out, carpet up, or just run new wires !!
cornishboater
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Thanks, I believe it may have been you that mentioned that the inhibit wire also ran through there, I have printed the diagram so I will have to dig it out. As I was only looking for the inhibit I probably didn't notice the cruise circuit.....
cornishboater
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where did you get them, I gotta know..........
cornishboater
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I have a long tester unit and I went directly from the ECU to each sensor which told me there was no continuity on the RH rear which was all well and good but it didn't obviously tell me where the problem was. After tons of wire wiggling I pinpointed the break and all was well with the world again. I hindsight it would have been far easier just to have run a new wire and left the old one there, such is life!
I am not going to get to involved as others know more than me. But. Unplug it at the sensor and the ecu, bridge the relevant pins at 1 end and check continuity to start with. Continuity isn't always the be all of tests but its a start.
Then check the "common" line.
Or you could do each line separately.
Were they good quality sensors?
You can check the sensor on its own to see if its ok with a DMM, which I assume you have, if you don't then get 1.
J
UnitLandy
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Well these aren't mine I have to say. They belong to a friend of mine who builds them for people. I can give him your details if you want one 
.
I build my own too to high standards as per the original but my workshop is in the works lol.
.I build my own too to high standards as per the original but my workshop is in the works lol.
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EAS Door input is on Pin-34 on C117. Look for PO wire (Purple / Orange Stripe).
Last edited:
UnitLandy
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Ooow. Where do you get those and what's it's full name?
UnitLandy
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Thanks Lads, BTW! All your input is fantastic. I hope it's helpful to each other too!
Digital Multi Meter
.You got 1 of them right if you make Daleks
.What diagnostics you using?
J
cornishboater
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Bob, or maybe dave.......... You can't own a P38 without a DMM (or a Dalek come to that..) I run a village hall and a dalek would be a great place for a camera to watch over the parties especially if the top was powered (and the exterminator laser)
UnitLandy
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Ah yes I have a DMM. What an idiot I am for not realising that, haha. Well like I say, DM me if you would like futher details. They £3000-£3500 a piece so they're not cheap mind you.
Datatek
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They don't but the ride height switch does and that is what causes the problems often attributed to height sensors.
UnitLandy
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Ah! Is that a fact. That's interesting. So would the diagnostic still register the sensor out of range if it was a bad connection the height switch?
That would be so much simpler...
Datatek
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Good question to which I do not have a definitive answer
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While I agree there could be unexpected behaviour, I'm not 100% convinced it would cause height errors itself.
Unfortunately there not any real info out there that I have found. Nigel Hewitt's page does give some help, no definitive details on the real protocol.
The Up & Down switches from the switch to the EAS ECU are simply grounded to the ECU pins 32 & 33 to tell the EAS to go up or down. The EAS output data signals on pins 7 & 25 tell the switch LED's what to display, plus are inputs to the BECM pins 9+18 for messages in the Instrument Cluster display. Pin 8 on the BECM is for the Wade Lamp in the instruments, but it's not clear if this is triggered by the EAS Data, or thye state of the top LED ?
So issues with C104-C204, and C102-C202 will have different impacts. Up-Down might need several presses to get the ECU to respond ? Intermittent data signals would me with the LED's, and potentially tell the BECM incorrect info.
Maybe between us all we can figure it out ??
Unfortunately there not any real info out there that I have found. Nigel Hewitt's page does give some help, no definitive details on the real protocol.
The Up & Down switches from the switch to the EAS ECU are simply grounded to the ECU pins 32 & 33 to tell the EAS to go up or down. The EAS output data signals on pins 7 & 25 tell the switch LED's what to display, plus are inputs to the BECM pins 9+18 for messages in the Instrument Cluster display. Pin 8 on the BECM is for the Wade Lamp in the instruments, but it's not clear if this is triggered by the EAS Data, or thye state of the top LED ?
So issues with C104-C204, and C102-C202 will have different impacts. Up-Down might need several presses to get the ECU to respond ? Intermittent data signals would me with the LED's, and potentially tell the BECM incorrect info.
Maybe between us all we can figure it out ??
Datatek
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Corrosion causing tracking between pins causes a variety of problems which I think confuses the ECU.
UnitLandy
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More often than not the up down switch lights operate for a few second without incident and the car will be roughly at the right height then all the lights on the switch come on and an EAS fault is read out on the dashboard (along with an airbag fault which is new)
brianp38dse
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What diagnostics are you using on the eas to calibrate the sensors
