Fiat Seicento 0.9 2000 SPI - Fuel Pump Relay Grounding Issue & Red Injector Error

Good morning to the forum

I have a petrol Fiat Seicento 0.9 2000, single point injection that didn’t start because the fuel pump was not working.

I checked everything and I found that the fuel pump relay does not get ground. So the fuel pump does not start.

When I feed the relay with external ground, the car starts and runs smoothly, but the red injector error stays on at the switchboard.

The black cable from the relay base seems to end at the ECU (pin 23) that is explained as “pump safety stop and rev counter signal (where relevant).

ECU is IAW FM.EC “Fiat 600 0.9 cm SPI FASE 2”

I do not know where else to look and maybe it is a faulty ECU. Does anyone have a similar problem and/or a solution?

did the car have any other fault warning lights on at the time this problem began. it sounds like the ecu is not commanding the pump to run. the engine ecu may not be seeing both cam and crank sensor signals. can you hear the pump run when you turn the ignition on before you start the engine

Dodano po 1 [minuty]:

Panagis wrote:

Good morning to the forum

I have a petrol Fiat Seicento 0.9 2000, single point injection that didn’t start because fuel pump was not working.

I check everything and I found that the fuel pump relay does not getting ground. So the fuel pump does not start.

When I feed the relay with external ground, the car starts and run smoothly, but the red injector error stays on at switch board.

The black cable from relay base, seems to end at the ECU (pin23) that is explained as “pump safety stop and rev counter signal (where reveland).

ECU is IAW FM.EC “Fiat 600 0.9 cm SPI FASE 2”

I do not know where else to look and maybe is a faulty ECU. Does anyone had a similar problem and/or a solution?

does it have an inertia cut off switch in the engine bay somewhere sometimes these get tripped

Inertia swich is under dash, near accelerator pedal.

If there is no weight on the fuel pump, check the inertia (resultant) sensor.
Schemes:
https://www.elektroda.pl/rtvforum/topic3698946.html
https://www.elektroda.pl/rtvforum/topic3406886.html

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