200 HPDI ECU Issue

[Sailorman295]

Trying to diagnose whether the ECU is faulty or if it is another issue. The ECU will not power the medium fuel pump or oil pump which both run off the same circuit on a 2003 200 HPDI. Also will not communicate with my laptop when I plug in the diagnostic connector. If I jump 12 volts to the red and yellow wires to the two pumps, the engine will start. Anyone have any experience with this issue?

[boscoe99]

The ECU does not provide power to the electric oil pump or the electric fuel pump. 12 volts electrical power is provided to these devices by the fuel pump relay.

Have you checked the relay?

[Sailorman295]

According to the repair manual only the 3.1 has a pump relay. I only found the main and driver relays. Also it has the issue of not communicating with my laptop.

[rodbolt17]

its not uncommon for a communication failure yet the system works fine.
the oil pump and the fuel pump DO NOT share the same circuits.
the same power supply but different ground paths.

[boscoe99]

According to the repair manual only the 3.1 has a pump relay. I only found the main and driver relays. Also it has the issue of not communicating with my laptop.

What is the complete model of the motor?

What service manual are you looking at? If Yamaha, what is the identity of the thing? It will begin with LIT-18616-

[boscoe99]

Here is the diagram out of a Yamaha 2003 VZ/Z200 service manual. LIT18616-02-82. Covers the 2.6l models.

Surely looks to me like both pumps get their 12 volts power from the relay. Am I missing something?

When you jumpered power to the red wire with a yellow tracer did you jumper to just one red wire with a yellow tracer with power going to both devices or did you have to jumper power to each of the red wires with a yellow tracer for each separate component?

Now as rodnut notes, each component gets its ground from a different wire and circuitry within the ECU. But we are talking about power to the components correct? And not the grounds.

Can rodnut with his eagle eyes, honed by years of shooting weapons, spot an error in the diagram?

[rodbolt17]

in the above diagram the fuel pump has no ground path(blue) wire.

[rodbolt17]

cant really see where the tied in the oil pump ground nor why it goes to the pulser coil connector nor how they got 3 black ground wires from the pulser coil connector.

[Sailorman295]

It is a model LZ200TXRB which has a different wiring diagram than the one you sent. I was looking at the Sealoc manual which is definitely not the best but I don't have the factory service manual. With the key on I jumped from the hot wire at the starter solenoid and ran it to the connector coming off the fuel pump which has two wires going into it. One should be the hot lead and the other one goes to the oil pump. When I hooked up the jumper wire the fuel and oil pumps both activated and I could start the engine. To me it seems like a break in the hot wire or the ecu is not activating it. Since the ecu is also not communicating it would appear to be an ecu fault. But can't guess with a $1300.00 part. My next step is to go back to the engine and check continuity on the red/yellow wire from the ecu to the pumps. Unless I'm missing something.

[boscoe99]

cant really see where the tied in the oil pump ground nor why it goes to the pulser coil connector nor how they got 3 black ground wires from the pulser coil connector.

Damn sam. I are impressed.

One attaboy for rodnut.

[99yam40]

If the ECU is not comunicating normally, will it when you put the hot jumper on?

Could be the ECU is not getting the power in needs also, not just the pumps

[boscoe99]

Your model might not have a fuel pump relay. But it has something that applies voltage to the red wire with a yellow tracer. Probably the main relay.

If the pumps do not have voltage on the red wires with a yellow tracer then find out why.

The voltage does not come from the ECU.

The voltage does not come from the ECU.

The voltage does not come from the ECU.

[Sailorman295]

I did not check to see if the ecu would communicate with the jumper hooked up. That's a good point. I did try swapping the two relays as they are identical and it still had no power through the red/yellow wire.

[99yam40]

I did not check to see if the ecu would communicate with the jumper hooked up. That's a good point. I did try swapping the two relays as they are identical and it still had no power through the red/yellow wire.

then I would check were the power was coming into if it is not coming out where it should be just to pin point/make sure where it is loosing it

[Sailorman295]

That's what I'm trying to determine, where the 12v for the pump should be coming from. The wiring diagram in the Sealoc manual is almost useless but I don't have time to get my hands on the Yamaha manual so I will have to eyeball the wiring to find where the R/Y wire originates from. I think Boscoe is correct that it must come from some sort of relay so when the key is turned on it sends voltage through the wire and then the ecu grounds the pump for about ten seconds to build up pressure. Then when it starts it supplies a constant ground. Going back to work on the boat tomorrow, will find out one way or another what the issue is.