bonok

hi everyone...

here's my info: jdm automatic b16a with p30 ecu.

tests done so far:

1) test my vtec solenoid (single wire) continuity to A4 ECU terminal. - OK

2) vtec oil pressure switch has 2 wires running from it :
test female connector terminal 1 continuity to D6 ECU terminal. - OK
test female connector terminal 2 continuity to G101 (thermostat housing) ground. - OK
(should be grounded if i'm not mistaken)

3) done continuity check (ignition off) between the 2 male switch terminal; there is. - OK

4) done voltage test (ignition on) :
- between female connector terminal 1 & body ground
- between D6 ECU terminal & body ground;
both test gives out 12V - according to the honda manual there is open in the wiring.

my problem is how to track down the open in the wiring & could anyone give me a detail method on how to repair the open...

thanks...

actionpaintball

If you are just trying to track down where the wire is "open" or "cut"...you want resistance or ohms. Start at either and and keep probing every few inches; when you finally get infinite ohms (not close to zero) your open wire is within the point you just measured and the previous point you just measured. Most of the time it will be near a wear area such as a firewall, or near an exhaust route or rubbing location.

Repair by replacing and/or splicing in new wire. If you find its been rubbing-might want to add a grommet or heavy insulation or a least a length of shrink tubing. Solder is your best friend.

b18b

I had this same problem with my swap and you are on the right track of doing this correctly. Now what you need to do is break out the helms manual/cd/online and verify the wire colors and that you didn't make a mix up of which was suppose to be ground on your "part 2" and don't forget when you look at the ecu connector verse the ecu female connector mirror the pin outs as you do the test I know sounds weird but i think you get the point. Finding these small mistakes can be a pain but it pays off when your car runs perfect.

Fabrik8

90% of the time, wire breakage happens at the engine bay connections because that's where the biggest stress concentration is and where most of the fatigue is (from engine vibration)..

But, I'm slightly confused about your test results. [strike]It sounds like everything is working fine. I don't think you should have continuity across the switch terminals with the engine off though; as far as I remember the switch closes (completes the circuit) when the oil pressure is high enough. So you shouldn't have continuity across the switch terminals when the engine is off, because you have no oil pressure.[/strike]

You were testing the wire continuity with the connectors on both ends unplugged, correct?


Edit: My memory is apparently slipping and I had it exactly backwards. The switch is normally closed (grounding the signal to the ECU) and opens with enough oil pressure. Sorry for the confusion.

I'm going to think about what you're saying for a little while. Something doesn't make sense, but it sounds like you're probably just interpreting something the wrong way.

Fabrik8

Ok, so you have continuity (at the connector) between the switch and ECU, and switch to ground. The have continuity through the (unplugged) switch. You also have 12V at both ends of the signal wire going to the ECU, which means that the ECU is biasing the signal properly and also that you don't have any open wiring. I can't see what part of the manual is telling you that you have an open wiring connection. Everything sounds fine to me.

So, you haven't actually tested the operation of the switch yet, you've only tested continuity in the off state. You need to get a buddy to hold the voltmeter and check to see if the 12V signal goes to ground with enough oil pressure. You're getting a pressure switch CEL for a reason, but you haven't tested the rest of the things that will tell you why.

bonok

i'll try that if all else fails...thanks...

bonok

actually i unplugged the connectors at the switch & cannon plug (@ shock tower) : test the continuity between them
then i test the continuity from the cannon plug to the ecu (by probing at the back of connector without unplugging the ecu)

i think i should do the continuity test again with the ecu connector unplugged...

but the voltage test have to be done with the ecu connected, rite?

bonok

i'm not referring to an actual honda manual (sorry). here's the manual i'm referring to :

http://ww2.justanswer.com/uploads/Vi...75608_code.pdf

i know it's different but i think the concept is the same...

how to check to see if the 12V signal goes to ground with enough oil pressure...detail me please...thanks

GULLIE

Before you kill yourself in diag...Code 22 also comes from low oil level...have you checked that?...start with the simple things

Fabrik8

You can test it the same way you were checking for 12v before. Test right at the ECU, because that's the easiest place to check while the car is in motion, and that's the important part anyway. The ECU sources 12v for the pressure switch (which answers your other question; the ECU connector has to be plugged in to get 12V) and the switch pulls the 12V signal to ground. So when checking the signal wire that goes to the pressure switch, you should see 0V below the oil pressure threshold (because the switch normally is connected to ground), and 12V above the oil pressure threshold (because the switch will open and disconnect from ground).

When you start the car, do you get that CEL right away, or only when you try to go into the VTEC range of RPM?


Here's a PDF excerpt from what appears to be one of the Helms service manuals, it has an easier to understand flowchart than the link you posted:

http://www.justanswer.com/uploads/th...ystem_test.pdf

This is kind of nice because it's just a switch, so it's either on or off. If it doesn't behave like that, there's something wrong. It's much easier than trying to diagnose any type of analog sensor.