Service manual

G424F(FE) Service Manual Chapter 9. Advanced Diagnostics 267
Table 2. Diagnostic Fault Codes (Flash Codes) cont’d.
DFC PROBABLE FAULT
FAULT
ACTION *
CORRECTIVE ACTION
FIRST CHECK
424
EST4_Open EST4
output open, possibly open
EST4 signal or defective
spark module
TurnOnMil
Check coil driver wiring and connector
for open circuit
SECM Pin A6 (EST4) to OEM ignition
system.
See application manual. Verify GND on
ignition module Pin A (of both
connectors)
Verify +12 Vdc on ignition module Pin
B (of both connectors)
Refer to application manual for specific
engine details.
425
EST5_Open EST5
output open, possibly open
EST5 signal or defective
spark module
None N/A
426
EST6_Open EST6
output open, possibly open
EST6 signal or defective
spark module
None N/A
427
EST7_Open EST7
output open, possibly open
EST7 signal or defective
spark module
None N/A
428
EST8_Open EST8
output open, possibly open
EST8 signal or defective
spark module
None N/A
431
EST1_Short EST1
output shorted high or low,
EST1 signal shorted to
ground or power or defective
spark module
TurnOnMil
Check coil driver wiring and connector
for shorts
SECM Pin A9 (EST1) to ignition
module Pin D (4-pin connector)
Verify GND on ignition module Pin A
(of both connectors) Verify +12
Vdc on ignition module Pin B (of both
connectors)
Refer to application manual for specific
engine details.
(*) Fault actions shown are default values specified by the OEM.