No power to fuel pump relay - Volvo Penta 5.0 GXI-E MEFI4

[Jslc]

My fuel pump was not turning on so I started checking the usual, fuses, loose connections, etc. I found that the relay wasn't getting power at any time - from turning the key on to cranking (used multimeter to check between pins 85 & 86). The ignition relay and start relays are getting power. I think the next thing upstream from the relay is the ECM. What are the next steps I can take in my diagnosis? ECM's are so expensive, I'd would love to know for sure before I buy a new one.

 

[alldodge]

When you turn the key to and before turning to start, do you hear anything (beep, buzz, click)?
When key is turned to ON, you have 12V on pins 85 and 86, correct?

 

[89retta]

Have you checked to make sure your lanyard for the kill switch is all the way on ?

 

[Bt Doctur]

 

[Bt Doctur]

the relay always has power, its the ground the ecm provides that causes the relay to close and power the fuel pumps
86 will have 12v all the time and grounding 85 should cause the pumps to run

 

[Jslc]

the relay always has power, its the ground the ecm provides that causes the relay to close and power the fuel pumps
86 will have 12v all the time and grounding 85 should cause the pumps to run

Thanks for the schematic and for your time. That was helpful. I think it is the ECM but tell me if there's anything else I should check. Here's what I've done:

- I do get 12V at pin 30 and pin 86 on the relay when grounded to the battery.
- The pumps do turn on when I jump 30 to 87 on the relay.
- I have zero resistance between pin 85 on the relay and pin 6 on the harness to the ECM (no short).

I've now come across several forums saying the ECM on this engine is prone to failure. Are there any recommended aftermarket chips that would be more reliable?

 

[Bt Doctur]

you need to see a short , 0 resistance, meter swings all the way toward 0 on the gauge between #85 and J1-6 pin on the ecm connector.
Unplug J1 ,locate pic 6 and read from pin 6 to #85 on the relay.. The ECM provides a ground connection,if the ECM`s pin 6 is not physically connected to #85 the relay wont operate the fuel pump
AVOID piercing the wire`s insulation to test

 

[alldodge]

I'm sure your right BT but If memory serves I was seeing pin 22 and there is no wire on 6, can check in a bit.

Jslc is there a wire on pin J1-6?

 

[Jslc]

BT, I didn't state very clearly but there is 0 resistance between #85 on the relay and J1-6 on the ECM.

AllDodge, I thought the same thing when referencing the schematic that BT sent. Then I popped open the harness and found that SB/Y does indeed go to pin 6 and the diagram is referencing the pins as if you were looking at the ECM, not the wiring harness. When looking at the plug in end of the wiring harness, if you orient the row with more pins on top, the pins go from 16 on the left to 1 on the right. Of course, the multi-meter confirmed this.

 

[alldodge]

From the doc I have it shows no connection to J1-6 but J1-23. Since you do have a wire on J1-6 then mine is different or in error :noidea:

 

[Jslc]

My boat matches the diagram BT posted. My engine is GXI-E MEFI 4. Maybe the diagram you have is a different variation?

 

[alldodge]

Woops, :facepalm: I cannot believe I was thinking I saw Gsi

I'll go back and sit down

 

[Bt Doctur]

If you have continuity (resistance value 0 ) from J1-6 to the relay then you may have a bad ecm PROVIDING all the other sensors are working to tell the ecm to switch on the fuel pumps, stand -by a sec

 

[Bt Doctur]

 

[Jslc]

I don?t have a scanner so it may be time to take it to the shop.

 

[89retta]

Have you checked your kill switch ? The tether was still on mine but slipped off enough to trip it. This has happened to a few people