Idle Control System — Troubleshooting Flowchart — Alternator FR Signal
6-66flowchart1
Inspection of Alternator FR signal.
2
Connect the PGM-FI test harness between the ECU and connector (page 6-19). Disconnect "B" connector from the main wire harness only, not the ECU.
3
Turn the ignition switch ON.
4
Measure voltage between B14 (+) terminal and A18 (-) terminal.
5
Is there approx. 5V?
NO
Substitute a known-good ECU and recheck. If prescribed voltage is now available, replace the original ECU.
YES
6
Turn the ignition switch OFF.
7
Reconnect "B" connector to the main wire harness.
8
Warm up engine to normal operating temperature (cooling fan comes on).
9
Measure voltage between B14 (+) terminal and A18 (-) terminal.
10
Does the voltage decrease when headlight and rear defogger are turned on?
YES
Alternator FR signal is OK.
NO
11
Stop engine.
(To page 6-67)