1jz- no engine light

[AeRoKaBn]

hello quick run down mz20 with jza70 motor.. few issues along the way.. heres another one lol

I went to go check for any codes cos i didnt know if my hydro fan was working properly although the car never gets hot whilst driving or on idle the fan doesnt seem to spin much on idle. Spins about the same when cold or hot on idle is this normal? (i can stop fan with my finger) so ive bridged the E1 and TE1 terminals in the diagnostics box and turned the car on and theres no engine light flashing, tried it again at running temp and still nothing

The lights and cat light will come on when key turned to "on" then the battery light will come on when i press the immobiliser. Then once started all the lights go out. Should the check engine light come on aswell and stay on for a few secs when the car starts? I cant be 100% certain but i think ive seen the engine light come on ages ago when i gave the car a bit of a thrashing with no map sensor connected. I disconnected the battery for a while and i never saw the light again. Where and what should i check before i go to an auto sparky, the car runs really good but id like to know my engine light works.

[EldarO]

i wired it up for you dude, so someones messed with it.

rip your glovebox out, its on a rectangular plug, 2 pins high, 11 or so pins long.

its a grey wire with a green stripe through it, make sure its connected, and the blub in your dash isnt blown.

[AeRoKaBn]

onya eldar always the first one in! Yeah just checked that plug and the diagrams u left with me and theres 2 grey/green wires next to eachother, the one towards the outside of the plug appears to be for auto and the inner one for manual according to diagrams (the dash plug is wired to the inner wire) but...

My plug isnt EXACTLY the same as the one in the diagram for example my grey/green wires are together and the diagram shows 2 wires inbetween the pair of green/grey wires. Theres a few other little things that are different but now that ive looked at the plug and diagrams ive got a bit more of a clue about it now.

Should i try unsoldering the connection and connect it to the outer grey/green wire? Wont fuck anything up?

[EldarO]

nah it wont fuck anything, give it a shot.
and the diagrams are for supra, so yeah, it'll be a bit different, the good thing about the toyotas is that most of them have the exact same coloring for the dashes

[AeRoKaBn]

ok ill try it, now if that still wont make my engine light come on do u know if that wire gives power to the light if theres a problem or on startup? I was thinking maybe bridge the diagnostic again and check the wires with mutimeter to see if either of them have power and then that would suggest a blown globe right?

[EldarO]

your diagnostics will work fine

its something to do with the CEL (check engine light) itself.

from memory the CEL gets power to turn on, so id start by cutting the CEL wire, giving the dash side power and seeing if it turns on, AFAIK it should go fine with 12V into it.

from there, if that works, start checking out the diagnosis side of things.

[wilbo666]

The check engine light has +12V via the gauge fuse at the Dash end, and the other end is grounded via the ECU W pin to turn the check engine light on. (putting +12V will not turn the light on...).

Using the ECU wiring diagram you should easily be able to trace the W pin. Use a multimeter...

You should also be able to manually ground the end of the check engine light that goes from the Dash -> ECU and see the check engine light come on!

Cheers
Wilbo

[AeRoKaBn]

ok cool il give it a whirl tomorrow

[AeRoKaBn]

oh hey wilbo i didnt see ur post, thanks for verifying that! nice job testing the 1jz/2jz map sensors too!

So if i look at the ecu pinouts there will be a "ECU W" pin somewhere in which il put a wire from that pin to earth to see if the CEL comes on? Is that right? and do i leave everything plugged in to the ecu when i do this?

[wilbo666]

oh hey wilbo i didnt see ur post, thanks for verifying that! nice job testing the 1jz/2jz map sensors too!

So if i look at the ecu pinouts there will be a "ECU W" pin

Yes!

which il put a wire from that pin to earth to see if the CEL comes on? Is that right?

Hmm well you could, I don't think this will harm the ECU as it is open collector...

The ECU is meant to provide the earth...

This would be an easy way to test the pin at the ECU...
1) trace W pin to one of the flying plugs near the ECU, use a multimeter, search for 0ohms resistance (and multimeters are like $10 these days so there is no excuse not to have one! ), you should also be able to find W listed in the little diag box on the side of the engine...
2) Connect a small light bulb (like a dash bulb...) or an LED with resistor (have to make sure the LED is the right way around tho), one end of the light bulb goes to +12V, the other end goes to the ECU W pin.
3) When the ECU earths the W pin the bulb will come on! (e.g. ignition on, engine not running, or TE connected to E1)...

You should be able to easily do this in the little diag box on the side of the engine...

Let me know if this doesn't make it clear!

Cheer
Wilbo

[AeRoKaBn]

Gotcha! il will give it a go and let ya know how it went

"i must spread the rep around before giving to wilbo again"

cheers mate

[AeRoKaBn]

Having some trouble with this engine light again hopefully someone can help me out...

I put a test light between 12v and the W pin in the diag box and get nothing even with TE and E1 bridged.

I used to check for codes from time to time with a test light (CEL's blown i think) and would get the flashes but not anymore.

I ran 12v thru the W pin on the ECU plug and the test light lit up when i grounded the W pin in the diag box so im guessing theres a problem with the ECU itself.

Is there anything else i can test or try to rig up some sort of CEL?

[George]

If the check engine light never ever comes then it's certainly your ECU.
If the light would turn on when you turn the key to "ignition on" (keep starter off) then check for TE wire breaks.

[AeRoKaBn]

cheers mate must be the ecu spewin...

[Wildsupra]

i have blown 3 1jz ecu's in the past 2 months, they must all be at the age of blowing. My eng check light wouldnt work either turned out to be blown caps in ecu (and car ran very badly) are you having trouble with the car running properly also?