Idle Control System — Troubleshooting Flowchart — Air Conditioning Signal
6-64flowchartA/C signal diagnostic; references Section 15 (Heater/Air Conditioning) for A/C clutch relay and air conditioner inspection.
1
Inspection of Air Conditioning 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 B8 (+) terminal and A18 (-) terminal.
5
Is there battery voltage?
NO
Substitute a known-good ECU and recheck. If prescribed voltage is now available, replace the original ECU.
YES
6
Reconnect "B" connector to the main wire harness.
7
Connect B3 terminal to A18 terminal.
8
Does A/C operate?
NO
Connect the YEL terminal of the 4P connector on the A/C clutch relay to body ground.
Connect the YEL terminal of the 4P connector on the A/C clutch relay to body ground.
Does A/C operate?
YES
9
Start engine.
10
Blower switch ON.
(To page 6-65)