DIAGNOSTICS
SERVICE MANUAL NUMBER 24
Page 5G-76
90-861327--1 OCTOBER 1999
Code 42 (1 of 3): Ignition Control (IC) Circuit
902 RED
TACH
B
A
3 PNK
121 BRN OR GRY
121 WHT
IC MODULE
ECM
MEFI 1
MEFI 2
J2-23
J2-8
J2-24
J2-6
MEFI 3
J1-10
J2-10
J1-24
J1-3
COIL
IGNITION
DISTRIBUTOR
When the system is running on the ignition module or in crank mode, there is no voltage on
CKT 424 and the ignition module grounds CKT 423. The ECM expects to detect a low volt-
age on CKT 423 during this condition. If the ECM sees voltage, it sets Code 41 and will not
go into the Ignition Control (IC) mode.
When the rpm for IC is reached (about 300 rpm), and CKT 424 voltage applied, CKT 423
should no longer be grounded in the ignition module, and the voltage should be varying.
If CKT 424 is open or grounded, the ignition module will not switch to IC mode. The CKT
423 voltage will be low and Code 42 will be set.
If CKT 423 stays grounded, the IC module will switch to IC mode but, because the line is
grounded, there will not be an IC signal and a trouble code 42 will be set.
DIAGNOSTIC AIDS:
Check for the following conditions:
•
Poor connection at ECM. Inspect harness connectors for backed out terminals,
improper mating, broken locks, improperly formed or damaged terminals, and poor
terminal to wire connection.
•
Damaged harness. Inspect the wiring harness for damage.
•
If the engine starts and stalls, it may set a false DTC 41 or 42. Clear DTC and repair
stalling condition.
After repairs, clear DTC following “Clearing Trouble Codes” procedure at the front of this
section. Failure to do so may result in DTC not properly being cleared.
Index
Содержание 305 CID (5.0L)
Страница 116: ...TROUBLESHOOTING SERVICE MANUAL NUMBER 24 Page 1C 34 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 142: ...MCM MODELS SERVICE MANUAL NUMBER 24 Page 2A 26 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 166: ...MIE MODELS SERVICE MANUAL NUMBER 24 Page 2B 24 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 285: ...STARTING SYSTEM SERVICE MANUAL NUMBER 24 Page 4A 30 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 315: ...IGNITION SYSTEM SERVICE MANUAL NUMBER 24 Page 4B 30 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 344: ...CHARGING SYSTEM SERVICE MANUAL NUMBER 24 90 861327 1 OCTOBER 1999 Page 4C 29 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 345: ...CHARGING SYSTEM SERVICE MANUAL NUMBER 24 Page 4C 30 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 364: ...INSTRUMENTATION SERVICE MANUAL NUMBER 24 90 861327 1 OCTOBER 1999 Page 4D 19 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 365: ...INSTRUMENTATION SERVICE MANUAL NUMBER 24 Page 4D 20 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 383: ...MAINTENANCE SERVICE MANUAL NUMBER Page 4E 18 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 721: ...DIAGNOSTICS SERVICE MANUAL NUMBER 24 Page 5G 94 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 779: ...GENERAL SERVICE MANUAL NUMBER 24 Page 7A 6 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 803: ...COLLECTORS SERVICE MANUAL NUMBER 23 Page 7C 16 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...
Страница 859: ...HURTH TRANSMISSIONS SERVICE MANUAL NUMBER 24 Page 8C 18 90 861327 1 OCTOBER 1999 THIS PAGE IS INTENTIONALLY BLANK Index ...