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K20A2 KPro4 Oil pressure light

Posted: Thu Oct 15, 2020 6:27 am
by Tom_93uk
Hi All.
I have a K20A2 EUDM EP3 type R engine swapped into my MK2 Golf. I am controlling it with the Kpro4.
I have wired the oil pressure light to a fault indicator LED on the golf's dash board and it is lighting up intermittently. I am not familiar with the K, it is my first experience with it so i dont fully understand the trigger for the pressure light. I have checked the oil pressure switch below the vtec solenoid (continuity to ground when engine off, no continuity when engine running) and checked the wire to the harness at the ECU. The engine is in nice condition (92k miles, chains etc done, fresh oil and filter, level checked) so no reason to suspect bad oil pump straight away. Can someone help me with the following questions:
Is it only the oil pressure switch that will trigger the light?
Should there be a fault code in the ECU along with the light being on?
Is it possible to view the pressure switch status in the ECU in K manager?
Am i totally missing the point with this switch being the culprit?

(I have ordered an oil pressure tester to physically check the oil pressure)

TIA

Re: K20A2 KPro4 Oil pressure light

Posted: Thu Oct 15, 2020 10:46 am
by Spunkster
Are you referring to VTEC oil pressure or regular oil pressure?

Re: K20A2 KPro4 Oil pressure light

Posted: Thu Oct 15, 2020 1:22 pm
by Tom_93uk
I don’t know that’s part of the question, since I have only driven below VTEC threshold so far (few hundred meters around the block)

Re: K20A2 KPro4 Oil pressure light

Posted: Thu Oct 15, 2020 1:32 pm
by Spunkster
VTEC oil pressure is only wired to the ECU and is used as a safeguard form going into vtec with low oil pressure. The regular oil pressure is not seen by the ECU and is just for a warning light on the dash.

Re: K20A2 KPro4 Oil pressure light

Posted: Thu Oct 15, 2020 11:48 pm
by Tom_93uk
Ok so assuming all the wiring is correct the low oil pressure light is triggered by the oil pressure switch and is independent of the ECU?
And i think you are saying that the VTEC unit has its own pressure sensor that is wired to the ecu and that this is used to stop vtec if it sees low pressure but that this and the switched light are separate? Will having low vtec pressure trigger the DTC?
Thanks

Re: K20A2 KPro4 Oil pressure light

Posted: Fri Oct 16, 2020 9:24 am
by Spunkster
VTEC pressure will trigger an error if it is enabled in the calibration and it has low pressure when it tries to activate VTEC.

Re: K20A2 KPro4 Oil pressure light

Posted: Fri Oct 16, 2020 11:18 am
by Tom_93uk
So in conclusion then it is only the oil pressure switch that can trigger the light? (Whether due to true low pressure or a fault with the wiring or sensor?)
A low oil pressure reading by the VTEC oil pressure sensor should give a separate dtc and prevent VTEC?
Do you know what the oil pressure switch activation value is?

Re: K20A2 KPro4 Oil pressure light

Posted: Sun Oct 18, 2020 11:58 pm
by Tom_93uk
I checked the oil pressure with a gauge this weekend:
cold engine idle = 80PSI
hot engine idle = 20 PSI
Hot engine 3000RPM = 80PSI
So suspect the wiring or the pressure switch is at fault. Also drove it yesterday and no issue with VTEC coming on. Are the oil pressure switches common fails on this engine?
Thanks
Tom