nsxe11074a.pdf

Idle Control System
Troubleshooting Flowchart Alternator FR Signal
This signals the PGM-FI ECU when the alternator is charging.
Inspection of Alternator FR
signal.
Connect the ECU test harness
between the ECU and connector.
Disconnect “D” connector from
the engine wire harness only, not
the ECU (page 11-21).
Turn the ignition switch ON.
Measure voltage between D9
( + ) terminal and A26 (-) ter-
minal.
Is there approx. 5 V?
5V
D9
A26
Substitute a known-good
ECU and recheck. If pre-
scribed voltage is now avail-
able, replace the original
ECU.
Turn the ignition switch OFF.
Reconnect “D” connector to the
engine wire harness.
Warm up engine to normal oper-
ating temperature (cooling fan
comes on). Voltage
D9
A26
Measure voltage between D9
( + ) terminal and A26 (-) ter-
minal.
Stop the engine.
Does the voltage decrease when
headlights and rear defogger are
turned on ?
Alternator FR signal is OK.
(To page 11-75)

(From page 11-74)
Disconnect “D” connector from
ECU only, not the engine wire
harness.
Disconnect the negative battery
cable from the battery.
Check for continuity between D9
terminal and body ground.
Continuity ?
Disconnect GRN connector from
the alternator.
Disconnect GRN connector from
the alternator.
GRN CONNECTOR
Connect WHT/RED wire to body
ground. Check for continuity between D9
terminal and body ground.
Check for continuity between D9
terminal and body ground. Does continuity exist ?
Does continuity exist ?
See Alternator Inspec-
tion.
See Alternator Inspec-
tion.
Repair open in WHT/RED wire
between ECU (D9) and alter-
nator.
Does continuity exist ?
Repair short in WHT/RED wire
between ECU (D9) and alter-
nator.