Bob R
Living Legend
I was looking at one of the wiring diagrams that idk has linked. Do you have an alarm installed, I don't think you do. Doesn't the alarm plug have a blank off plug installed? If it does, it would not hurt to remove the blank off, inspect the plug, clean it up, put on fresh grease and reinstall the blank off. I noticed the fuel pump relay has a wire feeding back to the alarm plug. It probably won't fix it but it is something that I don't think ever gets looked at.
bob
bob
DEcosse
If it's no Scottish it's CRAP!
First, how it works
The Fuel Pump needs Positive Power AND Ground to run.
The Pump Connector should have Ground hard-wired
The Pump Connector gets Positive Power via the Fuel Pump Relay
The Fuel Pump relay switches Power from the White/Blue wire to the Purple/White wire, when the relay is enabled.
The Relay Coil has Ignition-switch power on its positive and the coil negative is switched by the ECU ('ground' on the Black/Purple wire)
When the Ignition Circuit is enabled (Key on and Kill to Run) the relay is enabled by the ECU for 3 seconds only - testing after that time has elapsed will prove futile
So when checking for voltage, it must be done during the 3 second window, which can be reset by flipping Run switch to Kill and back to Run - each cycle will give a new 3 second window.
This is a huge clue right here:
The ECU has no way of knowing that the pump is actually running - it ONLY knows that the circuit to the Relay is complete (in terms of the Ignition Circuit switched to to Coil positive AND the ECU output itself seeing that voltage by its connection to the Coil Negative)
Since it notifies test complete and there is no Pump Error code then it suggests that all is good as far as the Relay goes (and again, the ECU is seeing that circuit as problem free)
It would 'fail' the test and post an error if the Ignition-supplied power on the relay coil positive was missing, so it confirms that the Ignition Circuit must be good.
And also that the ECU is processing correctly.
So
NOT an Ignition Circuit Issue
NOT an ECU (or interlock) Issue.
So that leaves several contenders:
1. No power on the White/Blue wire at the Fuel Pump Relay Socket - check for voltage at that terminal with respect to battery negative.
This can be also checked back at Fuse #2 - this is is 'hot' constantly even with ignition off; that same circuit feeds the key-switch main input power so is unlikely contender but should be checked to eliminate
Need to definitely have 12V at the relay socket itself.
2. The Relay is not closing properly
Seems unlikely given relays have been swapped
3. Wiring to the Pump Connector
Here is something you can try:
Disconnect the pump connector;
Pull the Pump Relay out of the socket;
Bridge between the White/Blue and the Purple/White wires - note that the White/Blue is already 'hot' even with ignition off
That will put 12V directly to the Pump socket
At the Pump connector check voltage between the Purple/White and
a) to Battery Negative
b) to the Black Wire at the Pump Connector
It should be 12V in both cases.
If good to battery negative but NOT to b) then you have a ground circuit issue
If you now DO have 12V between the Purple/White and Black wires at the connector, plug it in
Pump SHOULD Run with that bridge wire in place (to stop you will need to disconnect or remove bridge at relay socket)
If it does NOT run, problem with the Pump.
Give results of all of above and see where we go from there
The Fuel Pump needs Positive Power AND Ground to run.
The Pump Connector should have Ground hard-wired
The Pump Connector gets Positive Power via the Fuel Pump Relay
The Fuel Pump relay switches Power from the White/Blue wire to the Purple/White wire, when the relay is enabled.
The Relay Coil has Ignition-switch power on its positive and the coil negative is switched by the ECU ('ground' on the Black/Purple wire)
When the Ignition Circuit is enabled (Key on and Kill to Run) the relay is enabled by the ECU for 3 seconds only - testing after that time has elapsed will prove futile
So when checking for voltage, it must be done during the 3 second window, which can be reset by flipping Run switch to Kill and back to Run - each cycle will give a new 3 second window.
This is a huge clue right here:
The ECU has no way of knowing that the pump is actually running - it ONLY knows that the circuit to the Relay is complete (in terms of the Ignition Circuit switched to to Coil positive AND the ECU output itself seeing that voltage by its connection to the Coil Negative)
Since it notifies test complete and there is no Pump Error code then it suggests that all is good as far as the Relay goes (and again, the ECU is seeing that circuit as problem free)
It would 'fail' the test and post an error if the Ignition-supplied power on the relay coil positive was missing, so it confirms that the Ignition Circuit must be good.
And also that the ECU is processing correctly.
So
NOT an Ignition Circuit Issue
NOT an ECU (or interlock) Issue.
So that leaves several contenders:
1. No power on the White/Blue wire at the Fuel Pump Relay Socket - check for voltage at that terminal with respect to battery negative.
This can be also checked back at Fuse #2 - this is is 'hot' constantly even with ignition off; that same circuit feeds the key-switch main input power so is unlikely contender but should be checked to eliminate
Need to definitely have 12V at the relay socket itself.
2. The Relay is not closing properly
Seems unlikely given relays have been swapped
3. Wiring to the Pump Connector
Here is something you can try:
Disconnect the pump connector;
Pull the Pump Relay out of the socket;
Bridge between the White/Blue and the Purple/White wires - note that the White/Blue is already 'hot' even with ignition off
That will put 12V directly to the Pump socket
At the Pump connector check voltage between the Purple/White and
a) to Battery Negative
b) to the Black Wire at the Pump Connector
It should be 12V in both cases.
If good to battery negative but NOT to b) then you have a ground circuit issue
If you now DO have 12V between the Purple/White and Black wires at the connector, plug it in
Pump SHOULD Run with that bridge wire in place (to stop you will need to disconnect or remove bridge at relay socket)
If it does NOT run, problem with the Pump.
Give results of all of above and see where we go from there
Last edited:
Kevin frazier
Widowmaker!
No matches required
stollydriver
Live life to the full
TURBO200R4
stand up straight and grab the world by the a$$
might be interesting to know if u have power at those pins?
DEcosse
If it's no Scottish it's CRAP!
As explained in my post above, if there is no error on the pump-run test, then the ignition circuit must be complete (and that is down-stream of the alarm interlock)
TXtriple
SIC VIS PACEM PARA BELLUM
1olbull
Riding Motor Since 1950
Sure wish I knew enough 'lectricity to understand all that.
What a Ace in the hole you be, Ken!
What a Ace in the hole you be, Ken!
sonny
Living Legend
Just woke up and reading this will give it a shot and let you know all the details. Yesterdays heat knocked me out. Thank you for your help.
