10C
Inspection of ECM, Immobilizer Control Module and Its Circuit
ECM, Immobilizer Control Module and its circuit can be checked at ECM wiring couplers and immobilizer Control Module wiring coupler by measuring voltage. Described here is only inspection of Immobilizer Control Module. For inspection of ECM, refer to Inspection of ECM and Its Circuits:M13A without VVT .
CAUTION:
Immobilizer Control Module cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to Immobilizer Control Module with coupler disconnected from it.
Voltage Check
1) Remove Immobilizer Control Module, referring to Immobilizer Control Module Removal and Installation:M13A Model .
2) Connect Immobilizer Control Module coupler to Immobilizer Control Module.
3) Check Voltage at each terminal of coupler connected.
NOTE:
As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when ignition switch is ON.
1. Immobilizer Control Module
2-1. Immobilizer Control Module coupler (Vehicle not equipped with air bag system)
2-2. Immobilizer Control Module coupler (Vehicle equipped with air bag system)
Vehicle Not Equipped with Air Bag System
Terminal Circuit Normal Voltage Condition
G38-1 Ignition signal 10 – 14 V Ignition switch ON
0 – 0.8 V Ignition switch OFF
G38-2 Power source 10 – 14 V Ignition switch ON
G38-3 Coil antenna 2 0 V Ignition switch ON
G38-4 Coil antenna 1 0 V Ignition switch ON
G38-5
G38-6 		Blank — —
G38-7 Data link connector
(Serial data terminal) 		4 – 5 V Ignition switch ON
G38-8 Ground — —
G38-9 Blank — —
G38-10 Diagnosis output 0 – 14 V Ignition switch ON
0 V Ignition switch OFF
NOTE:
When measuring voltage at G38-4 and G38-3 terminals with ignition switch turned ON, be sure to turn ignition switch ON before connecting positive probe of voltmeter to G38-4 or G38-3 terminal. If it is not turned ON first, DTC 13 (Diagnostic Trouble Code 13) may be indicated.
Vehicle Equipped with Air Bag System
Terminal Circuit Normal Voltage Condition
G38-1 Ground — —
G38-2 Data link connector
(Serial data terminal) 		4 – 5 V Ignition switch ON
G38-3 Ignition signal 10 – 14 V Ignition switch ON
0 – 0.8 V Ignition switch OFF
G38-4 Power source 10 – 14 V Ignition switch ON
Resistance Check (Vehicle Not Equipped with Air Bag System)
1) Disconnect Immobilizer Control Module couplers from Immobilizer Control Module with ignition switch OFF.
CAUTION:
Never touch terminals of Immobilizer Control Module itself or connect voltmeter or ohmmeter.
2) Check resistance between each terminal of couplers disconnected (1).
CAUTION:
• Be sure to connect ohmmeter (2) probe from wire harness side of coupler.
• Be sure to turn OFF ignition switch for this check.
• Resistance in table below represents that when parts temperature is 20 °C (68 °F).
Terminal Circuit Normal Voltage Condition
G38-4 – G38-3 Coil antenna Continuity —