Page 385 of 4770
Page 386 of 4770
CIRCUIT DESCRIPTION
The distributor in the Engine Control System contains 3 pickup coils.
The G signals inform the ECM of the standard crankshaft position.
The NE signals inform the ECM of the crankshaft position and the engine speed.
wDuring cranking or idling, check waveforms
between terminals G (+) and G (±),
NE (+) and NE (±) of engine control module.
HINT: The correct waveforms appear as shown
in the illustration on the left.
wOpen or short in NE, G circuit
wDistributor
wOpen or short in STA circuit
wECM No G signal to ECM for 3 sec. or more with
engine speed between 600 rpm and 4,000 rpm. No N E signal to ECM with 2 sec. or more after
cranking.
CIRCUIT INSPECTION
INSPECTION USING OSCILLOSCOPE
Diagnostic Trouble Code Detecting Condition
Reference
Trouble Area
DTC 12 G NE Signal Circuit (No.1) (Exc. California spec.)
DTC No.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±336
Page 387 of 4770
Check for open and short in harness and
connector between ECM and distributor.Check resistance of each pickup coils in
distributor.
Repair or replace harness or connector.
DIAGNOSTIC CHART
WIRING DIAGRAM
Replace distributor housing.
Replace distributor housing.
Check and replace ECM. Check air gap.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±337
Page 388 of 4770
Remove distributor cap and rotor.
Using a thickness gauge, measure the air gap be±
tween the signal rotor and pickup coil projection.
Air gap: 0.2 ± 0.4 mm (0.008 ± 0.006 in.)
Check for open and short in harness and connector between
engine control module and distributor (See page IN±31).
Disconnect distributor connector.
Measure resistance between each terminal
shown in table below.
ªColdº is from ±10C (14F) to 50C (122F) and
ªHotº is from 50C (122F) to 100C (212F).
Check resistance of each pickup coils in distributor.
Check and replace engine control module.Repair or replace harness or connector.
INSPECTION PROCEDURE
Replace distributor housing.Replace distributor housing.
NE Pickup Coil
(NE (+) ± NE (±) )
Check air gap.
G Pickup Coil
(G1 ±G (±))
475 ~ 650 370 ~ 550 240 ~ 325 185 ~ 275 Resistance
ColdCold
Hot
Hot
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±338
Page 389 of 4770
CIRCUIT DESCRIPTION
The distributor in the Engine Control System contains 3 pick±up coils (G1, G2 and NE).
The G1, G2 signals inform the ECM of the standard crankshaft angle.
The NE signals inform the ECM of the crankshaft angle and the engine speed.
wOpen or short in NE, G circuit.
wDistributor
wOpen or short in STA circuit.
wECM No NE or G1 and G2 signal to ECM for
2 sec. or more after cranking.Diagnostic Trouble Code Detecting Condition
Open in G (±) circuit.Trouble Area
DTC 12 G NE Signal Circuit (No.1) (Only for California spec.)
DTC No.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±339
Page 390 of 4770
Check for open and short in harness and
connector between ECM and distributor. Check resistance of each pickup coils in
distributor.
Repair or replace harness or connector.
DIAGNOSTIC CHART
WIRING DIAGRAM
Check and replace ECM.Replace distributor. Replace distributor.
Check air gap.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±340
Page 391 of 4770
wDuring cranking or idling, check waveforms be±
tween terminals G1, G2, NE and G O of engine
control module.
HINT: The correct waveforms appear as shown in the
illustration on the left.
Disconnect distributor connector.
Measure resistance between each terminal
shown in table below.
Check for open and short in harness and connector between
engine control module and distributor (See page IN±31).
ªColdº is from ±10C (14 F) to 50C (122F) and ªHotº is
from 50C (122F) to 100C (212F).
Check resistance of each pickup coils in distributor.
INSPECTION USING OSCILLOSCOPE
Repair or replace harness or connector.
INSPECTION PROCEDURE
Replace distributor.
Reference
Resistance
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±341
Page 392 of 4770
Remove distributor cap & rotor.
Using SST (G1 and G2 pickups) and a thickness
gauge (NE pickup), measure the air gap between
the signal rotor and pickup coil projection.
SST 09240±00020 for G1 and G2 pickups
Air gap: 0.2±0.5 mm (0.008±0.020 in.)
Check and replace engine control module.Replace distributor housing assembly.
Check air gap.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±342