Electronic Ignition (EI) System Diagnosis. Opel GT 2007

For 1990-2009 cars only

Makes 🢒 Opel 🢒 2007 🢒 GT 🢒 Engine 🢒 Engine Controls and Fuel - 2.0L 🢒 Electronic Ignition (EI) System Diagnosis

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. Each ignition coil/module has the following circuits:

•	An ignition voltage circuit

•	A ground circuit

•	An IC control circuit

•	A low reference circuit

Diagnostic Aids

•	Depending on the location in the spliced ignition voltage circuit, a slight resistance can cause a misfire or a crank/no start concern. To pinpoint this condition perform a voltage drop test on the circuit.

•	Extended engine cranking time, may foul the spark plugs with excessive fuel and cause a crank/no start condition.

•	The ECM will set a misfire DTC for a high resistance or an open on the ignition control (IC) circuits.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

•	Engine Control Module Connector End Views

•	Engine Controls Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

•	Scan Tool Data List

•	Scan Tool Data Definitions

•	Scan Tool Output Controls

•	Scan Tool Snapshot Procedure

Circuit/System Verification

Important: Verify that the engine is in good mechanical condition before continuing with this diagnostic.

•	Observe the Engine Controls Schematic for the ignition coils/modules, and review the Ignition System Specifications and the spark plug inspection procedure to verify the following:

-	The ignition coil/modules are correctly connected

-	The proper firing order

-	The proper spark plug type

-	The proper spark plug gap and torque

-	Refer to Ignition System Specifications and Spark Plug Inspection .

•	A moderate resistance on any IC control circuit can cause a misfire.

•	Extended engine cranking time, may foul the spark plugs with excessive fuel.

•	If the engine will start, then observe the scan tool Misfire Current Cylinder parameters. This will indicate the affected ignition coil/modules, and if the condition is current.

Circuit/System Testing

Ignition OFF, disconnect the ignition coil/module harness connector at the affected ignition coil/modules.
Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the ground circuit terminal 1 and ground.

⇒	If greater than the specified value, test the ground circuit for an open/high resistance.

Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.

⇒	If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

Important: If the ignition fuse is open, it will be necessary to test the spliced ignition circuits and the components for a short to ground.

Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

Ignition OFF, disconnect the ECM.
Ignition OFF, test for less than 5 ohms of resistance between the ignition control (IC) circuit terminal 3 and the ECM.

⇒	If greater than the specified value, test the circuit for an open/high resistance.

Ignition OFF, connect the ECM.
Exchange the affected ignition coil/module with the ignition coil/module of a good cylinder.
Start the engine, observe the scan tool Misfire Current Cylinder parameters.

⇒	If the misfire transfers with the suspect ignition coil/module, replace as needed.

⇒	If the misfire does not transfer with the suspect ignition coil/module, refer to the Component Testing procedures below, and replace the spark plug if necessary.

⇒	If the misfire does not transfer with the suspect ignition coil/module, and the Component Testing procedures do not isolate a fault, replace the ECM.

Component Testing

•	Use the Spark Plug Inspection procedure to verify the integrity of the spark plugs. Refer to Spark Plug Inspection .

•	Use the J 26792 Spark Tester to verify the output of each ignition coil/module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Control Module References for ECM replacement, setup, and programming

•	Ignition Coil Replacement

•	Spark Plug Replacement