Hi everybody, I’ve encountered a problem with my fuel pump module on the passenger side (right side). However I’ve found out that the problem wasn’t the module itself, but actually is a bad (smaller) ground on the connector.



When I tested grounds on the fuel pump module connector, I found out there are 2 of them. One goes on a large Pin of the connector and the other one is a much smaller pin on the connector. The lager one gives me steady readings of 11.8volts, but the smaller one bounces from 3-4-9 volts none stop (passenger side)



Just to make sure I was on the right track for my findings I took the time to test the driver’s side Fuel pump module connector and it has the same 2 grounds, and both the smaller and bigger one gives me steady readings of 11.8volts.



So I would really appreciate if anyone could shine and share with me the wiring diagram for these fuel pump modules?



I will like to know exactly where the smaller grounds come from?



However, my best guess, right away is to suspect these smaller grounds come from the ECU… But I will like to know if I’m correct before I proceed any further. I want to know if they go to some other module before they get to the ECU?? (If thats where they go)

 

What model year?

 

Hey, my bad. The car is a 2014 GTC

 

Have a look at emanuals.com for a download.

 

@fastgtc ,
For the V8.

Johnny
.

 

Thank you Johnny, I appreciate your help!👍

So I was right, straight from the ECU (from pin 91).

Now I need to find out which one is pin 91 on the ECU connector?


**But first I need to find that T8 cf connector!**

Since it looks like the wires traveling from Pin 91 to the fuel modules go to it and from there to the modules.


Also worth mentioning is that I notice there is a 19 PWM signal to the Fuel Pump Module 1 (passenger side) coming from Pin 91 on the ECU, and 73 PWM from the same Pin 91 on the ECU to the Fuel Pump Module 2 (driver’s side)



So these are my next targets:

(Perhaps Johnny you could help me?)

1-Need to find the T8 cf connector location?

2-Also need help with the specific PWM signals values?

3-Could anyone share which one is pin 91 on the ECU connector? Perhaps a ECU Pin diagram??

 

Hello @fastgtc ,
I think there may be some confusion here.
It is not pin 91, the "T91" stands for the connector on the engine ecu, not terminal 91, the ecu has two plugs, one with 91 pin sockets, the other 105, pin 19 that you mentioned is located in the 91 pin connector, hence the diagram depicting T91/19, just as others will be depicted as say, T105/45.

I will look to find information on that T8CF.

Johnny

.

 

You’re right Johnny. My bad. Yes the 19th pin on the T91 connector, that is what I meant.

By the way, huge thank you for your guidance and help.

So a little more progress tonight.

I unplugged the ECU from its 105 and 91 connectors and found out that the drivers side Pump’Fuel Module connector lost it’s 11.8 volt signal (from the lead wire coming from Pin 19), showing not voltage at all.

But, mean while the same lead wire on the passenger’s side Fuel Module Connector didn’t. It still showing me 3-5-4 volts!!!😳

So I wonder what other wires go to this T8 CF connector?? Because that’s probably where the problem may be?

 

@Johnny Hotspur GT ,
do you have a service software with those diagrams ? what it is and where to get?

 

Hello @sazam ,
What year Bentley are you needing the diagrams for ?

This link will get you the 2011 - 2014 range.

https://cardiagn.com/bentley-continental-gt-wiring-diagrams-and-component-locations-2011-2014/


Johnny

 

hi @Johnny Hotspur GT , mine is 2005.

 

@Johnny Hotspur GT


Hi Johnny, I was wondering if you had a chance to look up the proper location of this infamous T8 cf connector??

Thanks in advance!

 

No luck yet, I will definitely let you know if I find it's location.

Johnny

 

Hi Johnny by any chance do you know where this white and red wire goes to? Or comes from? I can barely read it on the diagram.

Thanks!