G420E/G424E
Tier
LP Engine
Advanced Diagnostics
53
Table a. MI-04 Diagnostic Fault Codes (Flash Codes)
DFC
Probable Fault
Action
Corrective Action, First Check
38 IATSensorInputHigh
IAT signal disconnected, open circuit
or sensor malfunction
Stored Fault Code
(MIL Only)
Check TMAP connector and IAT
signal wiring for an open circuit
TMAP PIN 2 to SECM PIN 4
(SIGNAL)
TMAP PIN 1 to SECM PIN 1 (GND)
TMAP PIN 3 to SECM PIN 18 (XDCR
+5VDC)
To check the IAT sensor of the TMAP
disconnect the TMAP connector and
measure the IAT resistance
*See the IAT table in Chapter 6.0
42
EST1Low
Coil driver signal low or under-current
Stored Fault Code
(MIL Only)
Check coil driver wiring and
connector for shorts
SECM PIN 7(EST1) to COIL PIN A
Verify GND on COIL PIN B
Verify GND on COIL PIN C
Verify GND on COIL PIN D
12vdc on COIL PIN E
To check the Smart Coil internal
circuit disconnect the coil connector
and measure the resistance from pin
to pin
*See Smart Coil resistance check
in Chapter 6.0
