oil ISUZU TROOPER 1995 Workshop Manual

604-6 IGNITION SYSTEM
B INSTALLATION
3. Crankshaft Position Sensor (CKP sensor)
• Install crankshaft position sensor into the cyl­
inder block.
1~1 Before installation, apply small amount of en­
gine oil to the 0-ring.
~~~ Torque N-m (lb-in) I 10 (87)
2. Mounting bolt
• Tighten the bolt to the specified torque.
~~~ Torque N-m (lb·ft) I 63 (46)
TORQUE SPECIFICATIONS
Electronic Ignition (EI) assembly
1. Wiring connector
• Connect front propeller shaft joint and tighten
to the specified torque.
• Connect battery ground cable.
•
Tighten the exhaust & transfer protector fixing
bolt to the specified torque
~~~ Torque N-m (lb·ft) 37 (27)
N·m (lb·ftl
Spark plug
Exhaust & transfer protector
Crankshaft Position sensor
Fig. 604-11
•

DRIVEABILITY AND EMISSIONS 6E2-7
Former ISUZU Name New ISUZU Name Term
ALT Generator -GEN
Alternator
Generator -GEN
Assembly Line Communication Link
Data Link Connector -DLC
Assembly Line Data Link
Data Link Connector -DLC
Assembly Link Diagnostic Link
Data Link Connector -DLC
Backpressure Transducer
Backpressure Transducer-BPT
BARO Barometric Pressure -BARO
Baro
Barometric Pressure -BARO
Battery Voltage
Battery Positive Voltage-B+
Battery Voltage Correction Mode Battery Positive Voltage Correction Mode -B+ Correction Mode
Battery Volts
Battery
Positive Voltage-B+
BP Sensor Barometric Pressure Sensor -BARO Sensor
C.E. Light
Malfunction Indicator Lamp -MIL
CAL-PAK Electronically
Erasable Programmable Read Only Memory -
EEPROM
CAL-PAK
Programmable Read Only Memory -PROM
Calibration Pack Electronically Erasable Programmable Read Only Memory -
EEPROM
Calibration Pack
Programmable Read Only Memory-PROM
Cam Angle Sensor Camshaft Position Sensor -CMP Sensor
Cam Sensor Camshaft Position Sensor -CMP Sensor
Camshaft Sensor Camshaft Position Sensor -CMP Sensor
Canister Purge Evaporative Emission Canister Purge-EVAP Canister Purge
Catalytic Converter
Three Way Catalytic Converter-TWC
Check Engine
Malfunction
Indicator Lamp -MIL
Check Engine Indicator Malfunction Indicator Lamp -MIL
Check Engine Light
Malfunction Indicator Lamp-MIL
Code Diagnostic Trouble Code -DTC
Computer Command Control Engine Control Module -ECM
Computer Controlled Coil Ignition Electronic Ignition -El
Controlled Canister Purge Evaporative Emission Canister Purge-EVAP Canister Purge
Converter Three Way Catalytic Converter -TWC
Coolant Engine Coolant -EC
Coolant Level
Engine Coolant Level -ECL
Coolant Level Sensor Engine Coolant Level Sensor -ECL Sensor
Coolant Sensor Engine Coolant Temperature Sensor -ECT Sensor
Coolant Temp. Sensor Engine Coolant Temperature Sensor-ECT Sensor
Coolant Temperature Engine Coolant Temperature -ECT
Coolant Temperature Sensor Engine Coolant Temperature Sensor-ECT Sensor
Coolant Temperature Switch Engine Coolant Temperature Switch -ECT Sensor
Crank RPM Engine Speed -RPM
Crank Sensor Crankshaft Position-CKP

6E2-24 DRIVEABILITY AND EMISSIONS
ENGINE COMPONENT LOCATION (SOHC)
UNDERHOOD
FUSE/RELAY
CENTER
8 A
T
T
E
R y
0 COMPUTER HARNESS
C1 Engine control module (ECM) *
C2 DLC diagnostic connector
C3 "Check Engine" Malfunction
indicator lamp
C4 Engine harness connectors (3)
C5 ECM harness ground
C6 Fuse panel
C7 Electronic ignition ground
CS ECM main relay
C9 Fuel pump fuse 15A
C11 Oxygen 1 OA heater fuse
C12 30A ECM main fusible link
0 ECM CONTROLLED
COMPONENTS
1 Fuel injector
2 Idle air control
3 Fuel pump relay
6 Ignition control module
6a Ignition coils
12 Exhaust gas recirculation
(EGR) VSV
13 Air conditioning relay
14 Evaporate emission canister
purge VSV
Fig. 6E2-15
Q ECM INFORMATION
SENSORS
®
A Manifold Absolute Pressure
B Heated oxygen sensor
C Throttle position sensor
D Engine
coolant temperature
E Intake air temperature -
sensor
F Vehicle speed sensor
K Power steering pressure
switch (in-line)
@ EGRVALVE
@CHASSIS GROUNDS
* The ECM is located behind the
console in the lower dash.
®
[::::J EMISSION COMPONENTS
(NOT
ECM CONTROLLED)
N1 Crankcase vent valve (PCV)
N2 EGR valve back pressure
transducer
N3 Spark plugs
N4 Fuel rail test fitting (for fuel
pressure test)
N5 Crankshaft position sensor
N15 Fuel vapor canister

DRIVEABILITY AND EMISSIONS 6E2-25
ENGINE COMPONENT LOCATION (DOHC)
®B
UNDERHOOD FUSE/RELAY CENTER
B A T
T
E
A y
0 COMPUTER HARNESS
C1 Engine control module (ECM)
C2 DLC diagnostic connector
C3 "Check Engine" Malfunction
indicator lamp
C5 ECM harness ground
C6 Fuse panel
C8 ECM main relay
C9 Fuel pump fuse 15A
C10 Injector resistor
C11 Oxygen 1 OA heater fuse
C12
30A ECM main fusible link
0 ECM CONTROLLED
COMPONENTS
1 Fuel injector
2 Idle air control
3 Fuel pump relay
6 Ignition control module
ignition control
6a Ignition coils
7 Knock sensor Module under
charcoal canister
12
Exhaust Gas Recirculation
(EGR) VSV
*
®®
Fig. 6E2-16
13 Air conditioning relay
14 Evaporate emission canister
purge VSV
15 Induction air control plate
system VSV
Q ECM INFORMATION
SENSORS
A Manifold Absolute Pressure
B Heated oxygen sensor
c Throttle position sensor
D Engine
coolant temperature
F Vehicle speed sensor
H Crankshaft
position sensor
J Knock sensor
(under intake
assembly)
K Power steering pressure
switch (in-line)
L Intake air temperature
@ EGRVALVE
@ CHASSIS GROUNDS
f----1 EMISSION COMPONENTS !.-----' (NOT ECM CONTROLLED)
N1 Crankcase vent valve (PCV)
N2 Exhaust gas
recirculation valve
back pressure transducer
N3 Spark plugs
N4 Fuel rail test fitting (for fuel
pressure test)
N15 Fuel vapor canister
* The ECM is located behind the
console in the lower dash.

6E2-26 DRIVEABILITV AND EMISSIONS
ENGINE CONTROL MODULE WIRING DIAGRAM (1) (SOHC}
To ignition
switch 10 A
Meter fuse Underhood
connectors
located driver's side
shock tower
"Check Engine" MALFUNCTION
.-----------..:.:.1 N.:.:D:..:.IC=A~T~O:..:.R.:....=:.LA..::.M.:..::P:..___-,--___.:O:..:.R.:.:.N::.._IY.....:E:..:L=----1 c4
.------~~----~~O:..:R:..:N/~8~L=-=K--~ C 2
TCM
(C91-C8)
Engine Control Module(ECM)
"Check
engine" light control
DLC Diagnostic Request Input
Serial
data inpuVoutput
.--------f---+-....::...::;_;__=---_-1 A 12 System ground
Common
Data Link Connector (White) Chamber L.....::.=::....=..:=-=----+---1 C12 System ground
Intake air
temperature sensor
Throttle position
sensor
Manifold absolute pressure sensor
Engine
Coolant Temperature sensor Heated
oxygen
J-,.:..:W:.:..H.:..:T.:.:I8:..:L:.:U:......__ __ ....-To Fuel
RED/BLU (M/T)
1---=-'L T'-.!8~L:!:U'--l(.::::A/T!....!...!....) ---< f------lt+-~!,!..._'H---1 83
BRN/8LK
84
8RN/WHT 85
BRN/RED 87
8RN!YEL
BS
1---------~~~B~L~U~/8~L~K~--I 07
BLK/WHT
TCM
(C91-C6)
BLK/WHT 1------------4>---< t-----=~:..:.:..:_.:..:_ ....... -1 02
1-----------~ f----'-=-'-==--....-1 06
1-----------~ f--.-::..:=.=.:....=..c~-+--1 A 1
BLU/ORN
H02S Signal Input
H02S Ground
lAC coil "A" HI
lAC coil "A" LO
lAC coil "B" HI
lAC coil "B" LO
IAC=IDLE AIR CONTROL
Intake
Air Temperature(IAT)
signal input
Sensor ground
TPS signal input
5 volt reference
MAP
signal input
1---------'----...._.G:=.:..:.RY-=--------1 A 11 Sensor ground
1-------;---.:::G:..:R_;_YI:...::8:..:L::..:K:__---I 012 Engine Coolant Temperature
signal input
Fig. 6E2-17
•

DRIVEABILITY AND EMISSIONS 6E2-29
ENGINE CONTROL MODULE WIRING DIAGRAM (1) (DOHC)
Underhood connectors
located driver's side
shock
tower
To ignition
switch 7.5AMP ,.... ~ ®
I
I
Meter fuse I "Check Engine" I Malfunction I Indicator Lamp I
I
'
I 8LK/8LU I
D
I l TCM (C91-C8) 1
~ 1 2 ~ ~ co.;;mo~~ : ata Link Connector (White) Chamber 1 0 Common1 Chamber 1 Heated oxygen -= I
rg
=F
leair s ontrol C] alve
ld c v
M
te anifold
air
mperature sensor
Throttle position sensor
Manifold absolute pressure sensor
Engine
Coolant
T emperature
Sensor
sensor I
I
-A/IN-1:'1 WHT/8LU I
~ RED/8LU (M/TI I
~ ""21 L T 8LU (A/TI II ....::....1 ,1,
8LK/GRN :,
I
I
I
I
cam l:
I
I
Au A )I y"-\1 r--
8 8LK/WHT I I
I
I
I
8 ~ 1--II
~ r£ \ 'I A ,1,
8LU/ORN I
r£ ~ I
8 ~ f--I A I
I
I
_A& a A I y"-I r--I 8 I
I
I
Fig. 6E2-20
VLT
ORNNEL
ORN/8LK
8LK/8LU
I 8LK/8LU
To Fuel
pump relay
( ) RED ( v v
8LU
~ -8RN/8LK
8RN/WHT
8RN/RED
8RNNEL
8LU/8LK
TCM (C91-C6)
8LK/WHT !
RED/8LU
8LU/ORN
TCtM
(C91-C5)
GRY/RED
GRY
GRY/8LK Engine
Control
Module (ECMI
.-----
AS "Check engine" light control
C4 DLC Diagnostic Request lnpu
C2 Serial data input/output
A12 System ground
C12 System ground
83
H02S Signal input
82 H02S ground
84
lAC coil "A" HI
85 lAC coil "A" LO
87 lAC coil "8" HI
86 lAC coil "8" LO
lAC = Idle Air Control
D7 MAT signal input
D2 Sensor ground
D6 TPS signal input
A1 5 volt reference
D9 MAP signal input
A11 Sensor ground
D12 Engine Coolant Temperatur e signal input
......__

DRIVEABILITY AND EMISSIONS 6E2-33
ENGINE CONTROL MODULE (ECM) CONNECTOR IDENTIFICATION
This engine control module voltage chart is for use with a digital voltmeter to further aid in diagnosis. The voltages
you get may vary due to low battery charge or other reasons, but they should be very close.
The following conditions must be before testing:
• Engine at operating temperature • "Scan tool" not installed
•
Engine idling in "Close Loop" (for "Engine Run"
column) •
All voltages showing "Battery Position Voltage
(8+)" indicates battery or charging voltage
•
DLC Diagnostic terminal not grounded
VOLTAGE VOLTAGE
DC CIRCUIT PIN WIRE
KEY ENG. COLOR
"ON" RUN
DC CIRCUIT PIN WIRE
KEY ENG. COLOR "ON" RUN
ID 5.0V 5.0V THROTILE
POSITION ~TP~ SENSOR & MANIFOLD ABSOLUT P ESSURE A1 BLU/ORN 8+ B+ BATIERY FEED B1 RED/WHT
5 VOLT REFERENCE B+"ON" B+ OFF AIR CONDITIONING CLUTCH RELAY A2 GRY/YEL 0 "OFF" 0* ON
CONTROL o• o• OXYGEN SIGNAL GROUND 82 BLU
B+ s+ INTAKE
AIR VACUUM SWITCH VALVE A3 WHT/BLU (VSV) CONTROL
o• O*® SHIFT INDICATOR LAMP DRIVER A4 ORN/BLU .430MV
VALlES OXYGEN
SIGNAL INPUT
B3 RED
NOT NOT
IDLE AIR CONTROL (lAC) COIL "A" HI B4 8RN/BLK USABLE
USABLE
o• B+ "CHECK ENGINE" MALFUNCTION A5 VLT INDICATOR LAMP CONTROL
B+ B+ IGNITION VOLTAGE SIGNAL INPUT
AS RED/GRN
NOT NOT
lAC COIL "A" LO B5 8RN/WHT USABLE USABLE
NOT NOT
lAC COIL
"B" LO B6 BRN/YEL USABLE
USABLE
B+ B+ EVAPORATE EMISSION CANISTER PURGE A7 WHT/RED VSVCONTROL NOT
NOT
lAC COIL "B" HI B7 BRN/RED USABLE
USABLE
B+ 8~ EXHAUST GAS RECIRCULATION AS WHT/GRN VSV CONTROL
@VAR VAR TRANS TP SENSOR SIGNAL OUTPUT A9 8RN
o• o• ELECTRONIC IGNITION REFERENCE LO 88 YEL/BLK
o• 1.1V-ELECTRONIC
IGNITION REFERENCE HI B9 YEL/RED
2.4V
NOT USED B10
NOT USED
A10
NOT USED
B11 o• o• SENSOR GROUND A11 GRY
NOT USED B12 GRY/BLU o• o• SYSTEM
GROUND A12 8LK/PNK
VOLTAGE
VOLTAGE
DC CIRCUIT PIN WIRE
KEY ENG. COLOR DC CIRCUIT PIN WIRE
KEY ENG. COLOR "ON" RUN "ON" RUN
NOT USED C1 o• o• SYSTEM GROUND D1 BLK/BLU
4.7V 4.7V
SERIAL DATA INPUT/OUTPUT C2 ORN/8LK o• 0* SENSOR GROUND D2 BLK/WHT
@) B+ B+ FUEL PUMP RELAY CONTROL C3 PNK/WHT NOT USED D3
B+ B+ DLC DIAGNOSTIC REQUEST INPUT C4 ORN/YEL NOT USED D4
NOT USED C5 o• .1·.2V IGNITION
CONTROL OUTPUT D5 YEL
@B+ B+ POWER STEERING PRESSURE SWITCH C6 GRN/YEL SIGNAL INPUT 0.54V VAR
TP SENSOR
SIGNAL INPUT D6 BLU/RED
@O* o• PARK/NEUTRAL POSITION
INPUT C7 BLU/PNK VAR
VAR INTAKE AIR TEMPERATURE SIGNAL D7 BLU/BLK INPUT D7 BLU/BLK
NOT USED CB ® ® VEHICLE SPEED SENSOR
SIGNAL INPUT D8 WHT/BLK
B+"ON" 0 "ON" AIR CONDITIONING REQUEST SIGNAL C9 GRN/ORN
0 "OFF" B+"OFF"
INPUT 4.7V 1-2V MANIFOLD ABSOLUTE PRESSURE D9 GRY/RED SIGNAL
INPUT
NOT USED
C10 8-10V
VAR K.S.
MODULE INPUT D10 LTGRN/WHT
B+ B+ FUEL INJECTOR
DRIVER C11 BLU/YEL o• 4.9V IGNITION CONTROL BYPASS CONTROL D11 YELIGRN
o• o• SYSTEM GROUND
C12 BLK/PNK VAR VAR ENGINE COOLANT TEMPERATURE
D12 GRY/BLK SIGNAL
INPUT
NOT USED
C13 NOT USED D13
B+ 8+
FUEL INJECTOR DRIVER C14 BLU/GRN NOT USED D14
o• o• SYSTEM GROUND
C15 BLK/BLU B+ B+ FUEL INJECTOR DRIVER D15 ORN/BLU
8+ B+ BATIERY FEED C16 RED/WHT B+ 8+
FUEL INJECTOR DRIVER D16 ORN/8LU
* All voltages shown "0" should read less than .5 volts.
Reads battery positive voltage for 2 seconds after ignition "ON" then should read 0 volts. CD
®
® @
B+ with shifter in gear and clutch pedal not depressed.
B+ to 0 volts depending on Position of drive wheels
B+ for 2 seconds.
@
®
0 Volt with steering wheel cramped.
A/T Vehicles only

6E2-38 DRIVEABILITV AND EMISSIONS
CHART A-1
WILL NOT FLASH DIAGNOSTIC TROUBLE CODE (DTC) 12
NO "CHECK ENGINE" MALFUNCTION INDICATOR LAMP (MIL)
Circuit Description:
There should always be a steady "Check Engine" Malfunction Indicator Lamp (MIL), when the ignition is "ON" and
engine stopped. Battery positive
voltage is supplied directly to the light bulb. The Engine Control Module (ECM)
will control the light and turn it "ON" by providing a ground path through the VL T wire from the ECM to the bulb.
Test Description:
Numbers below refer to circled numbers on the diagnostic chart.
CD The Test Light provides a ground source to the "Check Engine" MIL. If the circuit is okay the "Check Engine"
MIL should
be "ON" when the terminai"A5" is probed.
® Battery feed terminals "C16" and "B1" are protected by a 30 amp ECM fusible link in relay/fuse center under
the hood near the battery.
If terminals "C16" and "B1" have voltage, the ECM grounds or the ECM are faulty.
® Using a test light connected to 12 volts, probe each of the system ground circuits to be sure a good ground is
present. Refer to the
"ECM Terminal End View" in front of this section for ECM pin locations of ground
circuits.
Diagnostic Aids;
Engine runs OK, check;
• Faulty light bulb.
•
VL T wire open.
• Meter fuse blown. This will result in no oil or generator lights, seat belt reminder, etc.
Engine cranks, but
will not run.
• Continuous battery-fuse or fusible link open. • Ignition RED/GRN wire to ECM open.
• ECM ignition fuse open. • Poor connection to ECM.
• Battery RED/WHT wire to ECM open.
TO FUEL .._..,==~ ,__,__-----, PUMP 15A
RELAY .--------~~-RED/WHT Engine
Control
Module(ECM)
BATIERY VOLTAGE
INPUT
ECM FUSIBLE RED/WHT TO LINK 30A '\.. BATIERY ~ VOLTAGE---BLK!RED ~---.-RED/WHT
TO IGNITION - BLK!YEL ~~~-BLK!YEL --'--'~"'---..__
SWITCH TO EGR VALVE VSV
CANISTER PURGE VSV
SECONDARY INTAKE VSV
REED VALVE VSV TO KS MODULE
LOCATED
PASSENGER
SIDE FENDER CHASSIS GROUND
"CHECK ENGINE"
MALFUNCTION
I/P CONNECTOR INDICATOR LAMP
METER (BLUE)
("";:; TO - BLK!YEL ~(---VEL~(;-VLT IGNITION 7.5A SWITCH
BLK ~ GRN MAIN RELAY
SOCKETEND SPLICES
TO ECM TERM. "D1" ECM SYSTEM GROUND
DATA
LINK CONNECTOR(WHITE)
1/P CONNECTOR
(WHITE)
BA TIERY VOLTAGE INPUT
IGNITION
VOLTAGE INPUT
"CHECK ENGINE"
MALFUNCTION
INDICATOR
LAMP DRIVER
~
DIAGNOSTIC REQUEST INPUT
' VIEW Fig. 6E2-24
./ .................................... __________________________ _

6E2-42 DRIVEABILITV AND EMISSIONS
CHART A-3
(Page 1 of 3)
ENGINE CRANKS BUT WILL NOT RUN
Circuit Description:
Before using this chart, battery condition, engine cranking speed, and fuel quantity should be checked and verified
as being OK.
Test Description:
Numbers below refer to circled numbers on the diagnostic chart.
CD A malfunction indicator lamp "ON" is basic test to determine if there is battery positive voltage and ignition
voltage supplied to the Engine Control Module (ECM). No data link connector data may be due to an ECM
problem. CHART A-2 will diagnose the ECM. If throttle position sensor voltage is over 2.5 volts, the engine
may be in the
"clear flood" mode, which will cause starting problems. The engine will not start without
reference pulses and, therefore, the "Scan tool" should indicate engine speed during cranking.
@ Because the electronic ignition system uses two plugs and wires to complete the circuit of each coil, the
opposite spark
should be left connected. If revolution per minute was indicated during crank, the ignition
control module is receiving a crank signal, but no spark at this test indicates the Ignition Control Module (ICM)
is not triggering the coils.
® The test light should blink, indicating the ECM is in control of the injectors. How bright the light blinks is not
important. However, the test light should be a J-34730-3 or equivalent.
@ This test will determine if the ignition control module is not generating the reference pules or if the wiring or
ECM are at fault. By touching and removing a test light to 12 volts on VEL/RED wire, a reference pulse should
be generated. If revolution per minute is indicated, the ECM and wiring are OK.
® High resistance in the spark plug wire could cause a "no start" condition. If a spark plug wire is found to be
faulty, replace it and retest system.
(SOHC)
I"M"
TOECM RED/GRN #1 BLU/YEL MAIN RED/GRN #2 BLU/YEL
RELAY
tRED/GRN
RED/GRN #3 BLU/YEL
RED/GRN #4 BLU/YEL
RED/GRN
#5 BLU/YEL
RED/GRN
#6 BLU/YEL
FUEL
INJECTORS ENGINE
CONTROL MODULE(ECM)
INJECTOR
RED/GRN
RED/GRN
RED/GRN
RED/GRN
RED/GRN
RED/GRN
IDOHCI BLU/YEL
BLU/YEL
l 1.3!l INJECTOR RESISTOR 1_
ORG/BLU
--+----
E~INE YEL/GRN D11 BLK/ORN -4>-BLK/YEL ----41sv---TO IGN BLK/RED -TOTACHOMETER SWITCH
BLK --:::L =
AND TCM (C91-D12)
CRANKSHAFT
POSITION
1 SENSOR
-........:::SHIELD
Fig. 6E2-26
•

DRIVEABILITY AND EMISSIONS 6E2-43
CHART A-3
-JJ!atfe 1 of 3)
ENGINE CRANKS BUT WILL NOT RUN
Q) • IGNITION "ON", IF "CHECK ENGINE" MALFUNCTION INDICATOR LAMP IS "OFF", SEE CHART A-1. • INSTALL TECH 1 "SCAN TOOL". IF "NO DATA LINK CONNECTOR", SEE CHART A-2. • CHECK THE FOLLOWING: THROTTLE POSITION SENSOR-IF OVER 2.5V AT CLOSED THROTTLE, SEE DIAGNOSTIC
TROUBLE CODE 21. IS REVOLUTION PER MINUTE INDICATED DURING CRANKING?
® • USING AN ST-125 (SPARK CHECKER) CHECK FOR SPARK ON TWO WIRES (2-4 OR 4-6).
® • USING AN ST-125 (SPARK CHECKER) J-26792 OR EQUIVALENT, CHECK FOR SPARK ON TWO WIRES (2-4 OR 4-6).
• CHECK ONE WIRE AT A TIME. LEAVE THE OTHER WIRES CONNECTED TO SPARK PLUG
WHILE CRANKING.
IS THERE SPARK ON BOTH
WIRES?
@ • DISCONNECT THE ENGINE HARNESS BLACK CONNECTOR
(DOHC) OR BLUE CONNECTOR (SOHC).
• USING A TEST LIGHT CONNECTED TO BATTERY POSITIVE VOLTAGE. • PROBE THE BLUIYEL
WIRE AT THE BLACK CONNECTION AND THE
BLU/GRN WIRE AT THE BLUE CONNECTOR
WHILE CRANKING THE ENGINE.
TEST LIGHT SHOULD
BLINK ON BOTH, DID
IT?
FAULTY IGNITION
MODULE
REFER TO L-----------1 CHART A-3
~20F3)
• CHECK ONE WIRE AT A TIME. LEAVE THE OTHER WIRES CONNECTED TO SPARK PLUG WHILE CRANKING. IS THERE SPARK ON BOTH WIRES?
NO SPARK
@ • IGNITION "OFF". SEE CHART A-3 (eA8£3 OF 3)
SPARK ON ONE
@ CHECK PAIR OR WIRES THAT DID
NOT SPARK.
EACH WIRE SHOULD MEASURE
LESS THAN 30,000 OHMS. IF OK, SWITCH COIL
ASSEMBLIES. DOES PROBLEM MOVE? •
DISCONNECT IGNITION
6-WAY CONNECTOR.
• IGNITION "ON". • MOMENTARILY TOUCH VEL/RED WIRE WITH A TEST
LIGHT TO 12 VOLTS WHILE
OBSERVING ENGINE SPEED.
IS REVOLUTION PER MINUTE
INDICATED?
VEL/RED WIRE OPEN OR SHORTED TO
GROUND
OR FAULTY ENGINE
CONTROL MODULE
CLEAR DIAGNOSTIC TROUBLE CODES AND CONFIRM "CLOSED LOOP" OPERATION AND NORMAL "CHECK ENGINE" MALFUNCTION
INDICATOR LAMP OPERATION.