Quote:
Originally Posted by bergerhag
There should not be any voltage on pin 19, using an ohm-meter to measure on live electronics is sure to get irratic results. Can you get the fuel pump relay to pull if you ground the cable to pin 19? (migth wanna disconnect it from the ecu first.
I have attached a different schematic, an older version. Might do you some good.
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Perhaps I didn't make it clear.....pin 19 ecu is the switching line for the fuel pump relay. If the fuel pump relay is on (closed) there will be no voltage at that pin. When the pump cycles off after 2 or so seconds of no engine rotation that line will rise to battery volts less the coil and diode voltage drops. As soon as the crank pulser detects movement the ecu grounds that line turning on the relay. As Nick said you might want check the relay and its connections first to make sure the relay is ok. If pin 19 doesn't ever ground the relay then it could be one of the inputs or outputs from the ecu that are the problem. The ecu tests all the sensors, the coil and the injector before it will ground that pin 19. There are from memory 3 failures that will prevent the ecu from allowing the engine to start and therefore will not ground the pump relay pin. There may be more. They are a shorted or open coil, a shorted or open injector and an input from the tps which is outside the normal operating limits. The water, air and pressure sensors are also checked but if they have faults the ecu will run with a set of defaults and allow starting to be attempted.
Hope that helps
BTW bergerhag the diagram is almost the same as the later ones except for the led I believe