EN(H4DOTC)(diag)-304
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
Check
Yes
No
1
CHECK OUTPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM connec-
tor and chassis ground.
Connector & terminal
(B135) No. 3 (+) — Chassis ground (–):
Is the voltage 10 V or more?
Go to step
2.
Go to step
3.
2
CHECK FOR POOR CONTACT.
Check for poor contact of ECM connector.
Is there poor contact of ECM
connector?
Repair the poor
contact of ECM
connector.
Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.
NOTE:
In this case, tem-
porary open or
short circuit of har-
ness or temporary
poor contact of
connector may be
the cause.
3
CHECK POWER SUPPLY TO PRESSURE
CONTROL SOLENOID VALVE ASSEMBLY.
Measure the voltage between the pressure con-
trol solenoid valve assembly and chassis
ground.
Connector & terminal
(R68) No. 1 (+) — Chassis ground (–):
Is the voltage 10 V or more?
Go to step
4.
Repair the power
supply circuit.
4
CHECK HARNESS BETWEEN ECM AND
PRESSURE CONTROL SOLENOID VALVE
ASSEMBLY CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM
and pressure control solenoid valve assembly.
3) Measure the resistance between the pres-
sure control solenoid valve assembly connector
and chassis ground.
Connector & terminal
(R68) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step
5.
Repair the short
circuit to ground in
harness between
ECM connector
and pressure con-
trol solenoid valve
assembly connec-
tor.
5
CHECK HARNESS BETWEEN ECM AND
PRESSURE CONTROL SOLENOID VALVE
ASSEMBLY CONNECTOR.
Measure the resistance of harness between
ECM connector and pressure control solenoid
valve assembly connector.
Connector & terminal
(B135) No. 3 — (R68) No. 2:
Is the resistance less than 1 Ω? Go to step
6.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM
connector
and pressure con-
trol solenoid valve
assembly connec-
tor
• Poor contact of
coupling connector