Acura NSX 1991 Manual page 233

Main Menu
PGM-FI System
Engine Control Module (ECM)
(From page 11-63)
Check for a short in the AP sen-
sor:
1. Turn the ignition switch OFF.
2. Connect the SCS service con-
nector.
3. Disconnect the AP sensor 3P
connector.
4. Turn the ignition switch ON (II).
Is DTC P1246 and/or P1247
indicated?
Check for a short in the wires
(VCC lines):
1. Turn the ignition switch OFF.
2. Disconnect the ECM connec-
tor D (22P) and F (26P).
3. Check for continuity between
body ground and ECM con-
nector terminals D10, F1 and
F14 individually.
Is there continuity?
Is there battery voltage?
Check for an open in the wires
(LG lines):
1. Reconnect all sensor connec-
tors.
2. Reconnect the ECM connector
D (22P) F (26P).
3. Turn the ignition switch ON (II).
4. Measure voltage between
body ground and ECM connec-
tor terminals A26 and B9 indi-
vidually.
Is there less than 1.0 V?
Substitute a known-good ECM
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal ECM.
Table of Contents
Replace the AP sensor.
Repair short to body ground
in the wire between ECM
(D10) and throttle angle sen-
sor and EGR valve lift sensor.
Repair short to body ground in
the wire between ECM (F1)
and MAP sensor or Accelerator
Position sensor.
Repair short to body ground in
the wire between ECM (F14)
and Accelerator Position sen-
sor.
Repair open in the wire(s)
between ECM (A13, CD and
PGM-FI main relay.
Check for poor connections
or loose wires at the PGM-FI
main relay.
Repair open in the wire(s)
between ECM (A26, B9) and
G101 that had more than 1.0 V.
WIRE SIDE OF FEMALE TERMINALS
ECM CONNECTORS
WIRE SIDE OF FEMALE TERMINALS