EN(H4SO)(diag)-75
Diagnostics for Engine Starting Failure
ENGINE (DIAGNOSTICS)
2
CHECK GROUND CIRCUIT OF FUEL PUMP.
1) Turn the ignition switch to OFF.
2) Remove the fuel pump access hole lid.
3) Disconnect the connector from fuel pump.
4) Measure the resistance of harness connec-
tor between fuel pump and chassis ground.
Connector & terminal
(R58) No. 6 — Chassis ground:
Is the resistance less than 5
:? Go to step 3.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
fuel pump connec-
tor and chassis
grounding terminal
• Poor contact of
coupling connector
3
CHECK POWER SUPPLY TO FUEL PUMP.
1) Turn the ignition switch to ON.
2) Measure the voltage of power supply circuit
between fuel pump connector and chassis
ground.
Connector & terminal
(R58) No. 5 (+) — Chassis ground (–):
Is the voltage 10 V or more?
Replace the fuel
pump. <Ref. to
FU(H4SO)-55,
Fuel Pump.>
Go to step 4.
4
CHECK HARNESS BETWEEN FUEL PUMP
AND FUEL PUMP RELAY CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between
fuel pump connector and fuel pump relay con-
nector.
Connector & terminal
(R58) No. 5 — (B362) No. 2:
Is the resistance less than 1
:? Go to step 5.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
fuel pump connec-
tor and fuel pump
relay connector
• Poor contact of
coupling connector
5
CHECK HARNESS BETWEEN FUEL PUMP
AND FUEL PUMP RELAY CONNECTOR.
Measure the resistance of harness between
fuel pump and fuel pump relay connector.
Connector & terminal
(R58) No. 5 — Chassis ground:
Is the resistance 1 M
: or
more?
Go to step 6.
Repair the short
circuit of harness
between fuel pump
connector and fuel
pump relay con-
nector.
6
CHECK FUEL PUMP RELAY.
1) Remove the fuel pump relay.
2) Connect the battery to fuel pump relay ter-
minals No. 3 and No. 4.
3) Measure the resistance between terminals
of fuel pump relay.
Terminals
No. 1 — No. 2:
Is the resistance less than 1
:? Go to step 7.
Replace the fuel
pump relay. <Ref.
to FU(H4SO)-41,
Fuel Pump Relay.>
7
CHECK HARNESS BETWEEN ECM AND
FUEL PUMP RELAY CONNECTOR.
1) Disconnect the connectors from ECM.
2) Measure the resistance of harness between
ECM and fuel pump relay connector.
Connector & terminal
(B136) No. 12 — (B362) No. 3:
Is the resistance less than 1
:? Go to step 8.
Repair the open
circuit of harness
between ECM and
fuel pump relay
connector.
8
CHECK POWER SUPPLY OF FUEL PUMP
RELAY.
1) Turn the ignition switch to ON.
2) Measure the voltage between fuel pump
relay connector and chassis ground.
Connector & terminal
(B362) No. 1 (+) — Chassis ground (–):
(B362) No. 4 (+) — Chassis ground (–):
Is the voltage 10 V or more?
Repair the poor
contact of ECM
connector.
Repair the open or
ground short circuit
of power supply
circuit.
Step
Check
Yes
No