Acura NSX 1991 Manual page 236

Main Menu
Idle Control System
Air Conditioning Signal
This signals the ECM when there is a demand for cooling from the air conditioning system.
Inspection of Air Conditioning
Signal.
Check for a short in the circuit:
1. Turn the ignition switch OFF.
2. Disconnect the 12P connector
from the cooling fan control
unit.
3. Turn the ignition switch ON (II).
4. Measure voltage between ECM
connector terminals C2 and
A26.
Is there approx. 10 V?
Check for an open in the circuit:
1. Turn the ignition switch OFF.
2. Reconnect the 12P connector to
the cooling fan control unit.
3. Turn the ignition switch ON (II).
4. Momentarily connect ECM
connector terminals A8 to
A26 several times with a
jumper wire.
(To page 11-118)
Table of Contents
Check for a short in the wire:
1. Turn the ignition switch OFF.
2. Disconnect the ECM connec-
tor C (12P) from the ECM.
3. Check for continuity between
ECM connector terminal C2
and body ground.
Is there continuity?
Substitute a known-good ECM
and recheck. If prescribed volt-
age is now available, replace
the original ECM.
See the air conditioner inspec-
tion (see section
ECM CONNECTORS
WIRE SIDE OF FEMALE TERMINALS
— Repair short in the wire
— See the air conditioner inspec-
22).
between the ECM (C2) and the
cooling fan control unit.
tion (see section 22).