1993 Vitara ECU Problem

[Moreira]

Hello

I am new around here.

I live in Portugal and I have a 1993 Suzuki Vitara 1.6 CC 8 Valve.

My ECU is a 33920-56B70

My Check engine light is on.

I’ve read a lot about possible causes but I haven’t solved my problem.

When I put the jumper between B and C in the diagnostic plug the lamp is always on.

I t doesn’t blink.

The engine runs but idle speed is not steady; it jumps from 800rpm to 1500 rpm.

There was a capacitor leaking and I changed the three of them.

There is a ceramic capacitor that disappeared and I don’t know its value you can see it in the pic I posted.

Thanks

Moreira

[Rhinoman]

You have a lot of burnt solder joints there, they all need to be resoldered. Have you checked that the components around the capacitor are still good?

[jtgh]

that is a lot of damage.
you should exchange ECU with EBAY sellers. many there.
or send it to. David (no affiliation)
David Ruberg Technical Services - Your Digital Repair Guy

My ECU is bad, now what?

tHAT cap is called C1 (circuit id C1)
it is ceramic,

have you looked under c111 in the corner? for damage.

that C1 cap
goes to B9 Memory wire, and the other side is ground.
it will be about 0.1uf 50v , so put a old fashioned wired one in there.
pin B9 to B2 ,

look carefull of this boric acid damage under all the CAN caps.
it eats copper for breakfast.
neutralize it with Baking sode (sodium Bicarbonate) mixed with water and dabbed on with a Q-tip.


you , ECU is toast if no code 12. (at least)

[jtgh]

c103 missing on the left is
47uf at 50vdc.
105C and lowest ESR on planet earth.

[Moreira]

Ok thanks

I have already changed all the electolitic caps, and cleaned up every thing.

Going to try to buy cap C1 and see if any thing around this area is bad.

[jtgh]

close examination of all traces under all BIG can CAPS is important. High Failure rates here.
these old years. to 95.

[minzu]

Originally Posted by Moreira

Hello

I am new around here.

I live in Portugal and I have a 1993 Suzuki Vitara 1.6 CC 8 Valve.

My ECU is a 33920-56B70

My Check engine light is on.

I’ve read a lot about possible causes but I haven’t solved my problem.

When I put the jumper between B and C in the diagnostic plug the lamp is always on.

I t doesn’t blink.

The engine runs but idle speed is not steady; it jumps from 800rpm to 1500 rpm.

There was a capacitor leaking and I changed the three of them.

There is a ceramic capacitor that disappeared and I don’t know its value you can see it in the pic I posted.

Thanks

Moreira

Hi dear Moreira, greetings to all community;
we have the same vehicle, the same ECM and the same problem :-(
Can you send me some complet photo of your ECM (up and down side),
the capacitor acid have maked a lot of damage.
tanks for your coutesy.
Bye Mimmo

[minzu]

Originally Posted by Moreira

Hello

I am new around here.

I live in Portugal and I have a 1993 Suzuki Vitara 1.6 CC 8 Valve.

My ECU is a 33920-56B70

My Check engine light is on.

I’ve read a lot about possible causes but I haven’t solved my problem.

When I put the jumper between B and C in the diagnostic plug the lamp is always on.

I t doesn’t blink.

The engine runs but idle speed is not steady; it jumps from 800rpm to 1500 rpm.

There was a capacitor leaking and I changed the three of them.

There is a ceramic capacitor that disappeared and I don’t know its value you can see it in the pic I posted.

Thanks

Moreira

Hi dear Moreira, greetings to all community;
we have the same vehicle, the same ECM and the same problem .
Can you send me some complet photo of your ECM (up and down side),
the capacitor acid have maked a lot of damage.
tanks for your coutesy.
Bye Mimmo

domesc@hotmail.com

[Moreira]

Hi there

I finally fixed my ECU.

I changed all the electrolytic capacitors.

The other problem that I found was that the copper of the tracks had disappeared.

I remade some of the tracks and now its working fine.

Thanks to all

Moreira.