S15/T15 4WD Jimmy V6-262 4.3L VIN W CPI (1993)
Chart A-5 Circuit (PCM)
Circuit Description:
When the ignition switch is turned "ON," the control module will turn "ON" the in-tank fuel pump. It will remain "ON" as long as the engine is
cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut
"OFF" the fuel pump within 2 seconds after ignition "ON" or engine stops.
The pump will deliver fuel to the TBI unit where the system pressure is controlled to about 62 to 90 kPa (9 to 13 psi). Excess fuel is then returned
to the fuel tank.
The CMFI pump will deliver system pressure that is controlled to about 380-420 kPa (55-61 psi). Excess fuel is then returned to the fuel tank.
Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This procedure applies direct voltage to run the fuel pump. If the pump runs, it may be a fuel pump relay circuit problem which the following
step will locate.
2. This step checks voltage from the battery and the ground circuit to the relay.
3. This test determines if there is voltage from the PCM terminal, "F6" to the relay connector.
4. This step completes the fuel pump relay circuit but if this diagnosis was used because the engine would not run then the oil pressure switch
should also he diagnosed.
