Engine Control Module (ECM)
NOTE: If this symptom is intermittent, check for a loose No. 5 BACK-UP LIGHTS, ALTERNATOR,
TURN SIGNALS (15 A) fuse in the under-dash fuse/relay box, a poor connection at ECM terminal
A7, or an intermittent open in the BLU wire between the ECM (A7) and the gauge assembly.
Is the low oil pressure light on?
Try to start the engine.
Does the engine start?
Check for an open in the wire or
bulb:
1. Turn the ignition switch OFF.
2. Connect the ECM connector ter-
minal A7 to body ground with a
jumper wire.
3. Turn the ignition switch ON (II).
Is the MIL on?
Substitute a known-good ECM,
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal ECM.
— Repair short in the wire
between No. 5 BACK-UP
LIGHTS, ALTERNATOR, TURN
SIGNALS (15 A) fuse and
gauge assembly.
— Replace No. 5 BACK-UP
LIGHTS, ALTERNATOR, TURN
SIGNALS (15 A) fuse.
ECM CONNECTOR A (26P)
Check for an open in the wires
(PG line):
1. Turn the ignition switch ON (II).
2. Measure voltage between
body ground and ECM connec-
tor terminals A12 and A25 indi-
vidually.
WIRE SIDE OF FEMALE TERMINALS
Is there less than 1.0 V?
Repair open in the wire(s)
between ECM and G101 (located
at intake manifold) that had
more than 1.0V.
— Repair open in the wires
between ECM (A7) and gauge
assembly.
— Replace the MIL bulb. WIRE SIDE OF FEMALE TERMINALS
ECM CONNECTOR A (26P)
Substitute a known-good ECM
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal ECM.
Turn the ignition switch ON (II).
The Malfunction Indicator Lamp
(MIL) never comes on (even for
two seconds) after ignition is
turned ON (II).
NOTE: If this symptom is intermittent, check for a loose No. 5 BACK-UP LIGHTS, ALTERNATOR,
TURN SIGNALS (15 A) fuse in the under-dash fuse/relay box, a poor connection at ECM terminal
A7, or an intermittent open in the BLU wire between the ECM (A7) and the gauge assembly.
Is the low oil pressure light on?
Try to start the engine.
Does the engine start?
Check for an open in the wire or
bulb:
1. Turn the ignition switch OFF.
2. Connect the ECM connector ter-
minal A7 to body ground with a
jumper wire.
3. Turn the ignition switch ON (II).
Is the MIL on?
Substitute a known-good ECM,
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal ECM.
— Repair short in the wire
between No. 5 BACK-UP
LIGHTS, ALTERNATOR, TURN
SIGNALS (15 A) fuse and
gauge assembly.
— Replace No. 5 BACK-UP
LIGHTS, ALTERNATOR, TURN
SIGNALS (15 A) fuse.
ECM CONNECTOR A (26P)
Check for an open in the wires
(PG line):
1. Turn the ignition switch ON (II).
2. Measure voltage between
body ground and ECM connec-
tor terminals A12 and A25 indi-
vidually.
WIRE SIDE OF FEMALE TERMINALS
Is there less than 1.0 V?
Repair open in the wire(s)
between ECM and G101 (located
at intake manifold) that had
more than 1.0V.
— Repair open in the wires
between ECM (A7) and gauge
assembly.
— Replace the MIL bulb. WIRE SIDE OF FEMALE TERMINALS
ECM CONNECTOR A (26P)
Substitute a known-good ECM
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal ECM.
Turn the ignition switch ON (II).
The Malfunction Indicator Lamp
(MIL) never comes on (even for
two seconds) after ignition is
turned ON (II).