Suzuki XL7 2007 Service Manual page 866

1H-2 Ignition System:
Electronic Ignition (EI) System Diagnosis
Diagnostic Instructions
• Perform the "Diagnostic System Check - Vehicle
Diagnostic Information: " prior to using this diagnostic
procedure.
• Review "Strategy Based Diagnosis: " for an overview
of the diagnostic approach.
• "Diagnostic Procedure Instructions - Vehicle
Diagnostic Information: " provides an overview of
each diagnostic category.
Circuit/System Description
The ignition system on this engine uses individual
ignition coils and ignition control (IC) circuits for each
cylinder. Ignition voltage is supplied to each bank of
ignition coils. The engine control module (ECM) controls
the ignition system operation. The ECM controls each
coil using the IC circuits. The ECM commands the IC
circuit low when a spark event is requested. The
sequencing and timing are controlled by the ECM.
Diagnostic Aids
• The ignition coils for each bank are fused separately.
If a fuse opens or the ignition voltage circuit opens
between the fuse and the splice, all the ignition coils
for one bank of the engine would be inoperative. If the
ground circuit opens at the engine block, the ignition
coils would be inoperative for one bank of the engine.
• Inspect the ignition coils for aftermarket devices. An
aftermarket device connected to the ignition coil
circuits, may cause a condition with the ignition coils.
Reference Information
Schematic Reference
"Engine Controls Schematics: "
Connector End View Reference
• "Engine Control Module Connector End Views: "
• "Engine Controls Connector End Views: "
Description and Operation
"Electronic Ignition (EI) System Description"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
Scan Tool Reference
• "Scan Tool Data List - Engine Controls - 3.6L (LY7): "
• "Scan Tool Data Definitions - Engine Controls - 3.6L
(LY7): "
• "Scan Tool Output Controls - Engine Controls - 3.6L
(LY7): "
Diagnostic Information and Procedures
Special Tools Required
• J 26792 Spark Tester
• J 43244 Relay Puller Pliers
Circuit/System Testing
NOTE
Do not perform this diagnostic procedure if
you were not sent here from a misfire DTC or
the Engine Cranks but Does Not Run
diagnostic.
1. Ignition OFF, disconnect the harness connector of
the ignition coil.
2. Ignition ON, load test for battery voltage between the
ignition voltage circuit terminal D and ground.
➢ If less than B+, test the ignition voltage circuit for a
short to ground or an open/high resistance. If the
circuit tests normal and the ignition circuit fuse is
open, test all the components connected to the
ignition voltage circuit and replace as necessary.
3. Crank or start the engine. Test for 200-400 mV
between the appropriate IC circuit terminal C and
ground.
➢ If less than the specified value, test the IC circuit for
a short to ground or an open/high resistance. If the
circuit/connection tests normal, replace the ECM.
➢ If greater than the specified value, test the IC circuit
for a short to voltage. If the circuit/connection tests
normal, replace the ECM.
4. Ignition OFF, test for 5 ohms or less between the low
reference circuit terminal B and the ECM housing.
➢ If greater than the specified value, test for an open/
high resistance in the low reference circuit. If the
circuit/connection tests normal, replace the ECM.
5. Test for 5 ohms or less between the ground circuit
terminal A and ground.
➢ If greater than the specified value, repair the open,
or high resistance in the ground circuit.
6. If all circuits/connections test normal, replace the
ignition coil.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Ignition Coil Replacement - Bank 1"
• "Ignition Coil Replacement - Bank 2"