3b s2 coupe resurrection

[andy10v]

Have you got another fuel pump relay to substitute?
Sounds like quite a large voltage drop from battery to actuators.

I have tried a spare fuel pump relay.

It will spin the engine over at good speed no bother, are you thinking something may be rather voltage sensitive?

[andy10v]

Where does 30/55- Ground for ECU and ECU sensors - G/BK (See details with a listing of the seven devices grounded through Pin T55/30) go?

[andy10v]

18/55- Constant power supply to ECU J220 - R/R- from power terminal 30 (+12V) Fuse S26 (5A) - passenger footwell as shown HERE, in this above ECU fuse panel call-out post). This constant power also feeds the Holding Relay for its work during start-up and shut-down.

Has 12v

[twoqu]

Isn't that the main ecu chassis ground? If so its in the footwell I think off the top of me head!
To double chec, ,see if there is continuity between the other ground pins and 30. If the injector earth does not have continuity with 30 than that makes sense!

[andy10v]

27/55- Switched Power to ECU from power (+12V) - BK/G - from Terminal 15 under the knee bolster - 15A circuit breaker, BK in BK/G out - S64

Has 12v with the ignition on.

[andy10v]

Isn't that the main ecu chassis ground? If so its in the footwell I think off the top of me head!
To double chec, ,see if there is continuity between the other ground pins and 30. If the injector earth does not have continuity with 30 than that makes sense!

That is what it reads like, I will pop off the glovebox and have a look.

Thank you for your patience

[twoqu]

We need power and earth. So if you don't have one or the other then thats an issue that needs investigating. Although if the ecu itself is not grounded I am surprised some of the output tests worked. Still it sounds like a probable cause.

[andy10v]

Pin 33 is black with a purple stripe, it goes into the top group of connected wires (I presume a collection of earths?)

[andy10v]

The loom then goes up behind the heater box and I cant see where that group grounds.

Is it worth grounding pin 33 or the whole lot to the chassis?

[newsh]

Grounding points behind dash are usually quite high up on the A pillar, a bolt with a load of rings on, sometimes these go rusty where water drips down.

[newsh]

If you're sure that pin is supposed to be grounded then why not try grounding it!


BTW it could be driver's side A pillar.

[andy10v]

I am not clear if 33 is a ground, or a ground reference? This diagram does not show it as a ground, but a 0V reference signal.

[andy10v]

Grounding points behind dash are usually quite high up on the A pillar, a bolt with a load of rings on, sometimes these go rusty where water drips down.

Cheers, got them to the left of the heater box.

[newsh]

Actually in this diagram it shown as not connected I think, it's a bit small on my laptop..

I am not clear if 33 is a ground, or a ground reference? This diagram does not show it as a ground, but a 0V reference signal.

[andy10v]

If you're sure that pin is supposed to be grounded then why not try grounding it!

Because I dont want to break something.

I am not sure if it is a ground? Daves list says

"30/55- Ground for ECU and ECU sensors - G/BK (See details with a listing of the seven devices grounded through Pin T55/30)"

Which makes it sound like the ecu uses it as a ground, the above diagram makes it look like its part of a signal circuit? S2central says it is a 0v reference signal for a pile for F96 , G42 , G61 ,G62, G66, G69