Engine Does Not Run on All Cylinders

FAULT TRACING INFORMATION

Conditions
^ DTCs absent.
^ Fault permanent.
^ Engine is running on more than three cylinders.

Fault Sources
^ Break in power lead to ignition coil.
^ Break in signal lead to ignition power stage.
^ Ignition power stage signal lead short circuited to ground or live.
^ Break in lead between ignition coil and ignition power stage.
^ Lead between ignition coil and ignition power stage short circuited to ground or live.
^ Contact resistance in contacts.
^ Defective injection valve.
^ Defective ignition power stage.
^ Defective ignition coil.
^ Defective spark plug.

NOTE: Erase DTCs after repair.

TESTING PROCEDURE





Check Which Cylinder Not Firing
^ START engine.
^ Disconnect injectors one by one until misfiring cylinder is identified by sound.
^ Continue fault tracing with: Check Spark Plugs, section below.





Check Spark Plugs
^ Remove spark plug from misfiring cylinder.
^ Check if spark plug damp or dry.

If spark plug dry:
- This means cylinder is starved of fuel.
- Test with a new injection valve.
If spark plug damp:
- This means there is no spark.
- Continue with: Check Ignition Coil, section below.





Check Ignition Coil
^ Replace old spark plug in cylinder.
^ Fit a new spark plug to ignition coil.
^ Place ignition coil so that spark plug grounded.
^ START engine.
^ Spark plug should not spark.

If spark plug sparks:
- Change all spark plugs.
If spark plug does not spark:
- Check control signal to ignition coil.

NOTE: It is very important that the correct spark plugs are used. Also check gaps of new plugs before fitting. Spark plug gap should be 0.7 - 0.8 mm.





Check Control Signal to Ignition Coil
^ Ignition OFF.
^ Disconnect ignition coil.
^ Connect an ohmmeter between ignition coil pins 1 and 2.

Ohmmeter should read approx. 1 ohm.

If value OK:
- Proceed to: Check Power Lead to Ignition Coil, Resistance, section below.
If value differs:
- Test with a new ignition coil.





Check Power Lead to Ignition Coil, Resistance
^ Ignition OFF.
^ Disconnect ignition coil.
^ Disconnect ignition relay in left wheel-arch.
^ Connect an ohmmeter between ignition coil connector contact 2 and relay base contact 3.

Ohmmeter should read approx. 0 ohm.

If value OK:
- Prodeed to: Check Control Signal to Power Stage, section below.
If value differs:
- Check lead between ignition relay contact 3 and ignition coil contact 2 for break.





Check Control Signal to Power Stage
^ Ignition OFF.
^ Disconnect power stage corresponding to faulty cylinder.
^ START engine.
^ Connect a voltmeter between ignition coil connector contact 2 and power stages connector contact 2, 5 or 7 (depending on which cylinder is faulty).

Voltmeter should read battery voltage.

If value OK:
- Prodeed to: Check Signal Lead Resistance to Ground, section below.
If value differs:
- Proceed to: Check Signal Lead, section below.





Check Signal Lead Resistance to Ground
^ Ignition OFF.
^ Power stage disconnected.
^ Connect an ohmmeter between power stage connector contact 2, 5 or 7 (depending on which cylinder is faulty) and ground.

Ohmmeter should read very high resistance.

If value OK:
- Proceed to: Check Lead Between Power Stage and Ignition Coil, section below.
If value differs:
- Check lead between power stage and ECM for short circuit to ground.





Check Signal Lead
^ Power stage disconnected.
^ Ignition ON.
^ Connect a voltmeter between power stage connector contact 2, 5 or 7 (depending on which cylinder Is faulty) and ground.

Voltmeter should read approx. 0 Volts.

If value OK:
- Check lead between power stage and ECM for break.
If value differs:
- Check lead between power stage and ECM for short circuit to live.





Check Lead Between Power Stage and Ignition Coil
^ Ignition OFF.
^ Disconnect connector to power stage corresponding to faulty cylinder.
^ Ignition ON.
^ Connect a voltmeter between power stage connector contact 1, 3 or 6 (depending on which cylinder is faulty) and ground.

Voltmeter should read approx. 0 Volts.

If value OK:
- Proceed to: Check Lead Between Power Stage and Ignition Coil, Resistance, section below.
If value differs:
- Check lead between power stage connector and ignition coil connector for short circuit to live.





Check Lead Between Power Stage and Ignition Coil, Resistance
^ Ignition OFF.
^ Ignition coil disconnected.
^ Power stage disconnected.
^ Connect an ohmmeter between power stage connector contact 1, 3 or 6 (depending on which cylinder Is faulty) and ground.

Ohmmeter should read infinite resistance.

If value OK:
- Proceed to: Check Lead for Break, section below.
If value differs:
- Check lead between power stage and ignition coil for short circuit to ground.





Check Lead for Break
^ Ignition OFF.
^ Ignition coil disconnected.
^ Connect an ohmmeter between power stage connector contact 1, 3 or 6 (depending on which cylinder is faulty) and ignition coil connector contact 1.

Ohmmeter should read approx. 0 ohms.

If value OK:
- Test with a new power stage.
If value differs:
- Check lead between power stage and ignition coil for break.