1996 p38 EAS

Jazbar said:

I have a wierd EAS fault.
No warning lights. No EAS fault codes. The pump refuses to energise.
Checked fuses/relay. Traced wires from fuse box to eas module -all ok. If you short across the relay switch terminals the pump will run.
Any ideas?
I've switched over eas Module and black relay. No joy.

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Dippypud said:

Is the relay socket clean ?

Any sign of arcing ?

Have you tried wiring the relay in with fly leads to by-pass any dodgy connections ... or even a known good relay ?

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Jazbar said:

I've tried a known good fuse board

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Datatek said:

Check the thermal trip in the compressor.

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Rubberknees said:

+2 thermal switch. was on mine a few years back. As posted follow wammers guide

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Jazbar said:

I've switched over a whole known working eas pump unit complete with valves and driver. So that would eliminate thermal switch?

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Datatek said:

Assuming that the replacement was indeed in full working order, yes.
If you have also checked the fuse box, then perhaps check the connectors in the EAS box, the contacts become loose over time.

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Jazbar said:

I've checked connectors, checked white plug in passengers footwell. Replaced ecu and delay relay with known working parts.
Could becm cause this?

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wammers said:

Compressor has nothing to do with valve block or driver pack other than the pressure switch screwed into valve block. It is a totally separate circuit.

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Jazbar said:

Work performed so far: checked & confirmed continuity to relay on fuse board from eas ecu. Confirmed relay function. Confirmed pump running when shorting relay switch terminals.
Replaced eas ecu and delay relay with good working parts.
Checked white plug in passengers footwell.
Replaced entire eas unit with known working unit.
Slow 35mph on display. Orange eas light on.
No fault codes. Valves will activate in test mode. Pump will not.
No feed to eas relay in fuse box from eas ecu. Checked connectors.
Car has had water leak into it.
I'm suspecting possible dry joints or corrosion in becm. Airbag fault Also.

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Datatek said:

If you have the "Slow 35 Mph" message, there is a hard fault present and that is why the pump will not run. It will not run until the fault is cleared.
What diagnostics are you using?
As Wammers said, the BECM has nothing to do with the problem. Interfere or change the BECM and you will enter a world of pain.

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wammers said:

Mornin Keith.

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Datatek said:

Morning Tony, all well I hope in flat B?

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wammers said:

Not terrible, up at 6.15 felt pretty ropey until about half an hour ago but coming to a bit now. Hows life on the flood plains?

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Datatek said:

If you have the "Slow 35 Mph" message, there is a hard fault present and that is why the pump will not run. It will not run until the fault is cleared.
What diagnostics are you using?

So, could I be chasing EAS ghosts that aren't there?
The eas ecu is fault code free.
The Becm has airbag fault and communication error with centre console though everything works.
As Wammers said, the BECM has nothing to do with the problem. Interfere or change the BECM and you will enter a world of pain.

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