Faulty Signal

Checking Air Conditioning Relay
- Ignition ON.
- Activate air conditioning (A/C).
- The air conditioning relay should switch ON and OFF after a second.

If reading is OK:
^ Proceed to: Checking Ignition Spark Cylinders 3, 4, 5 and 6 section below.

If reading is incorrect:
^ Proceed to: Checking Air Conditioning Relay Signal Cable section below.





Checking Air Conditioning Relay Signal Cable
- Ignition OFF.
- Remove air conditioning relay F from relay base.
- Ignition ON.
- Connect a voltmeter between relay base terminal 4 and ground.
- The voltmeter should read 2 - 8 Volts.

If reading is OK:
^ Try a new air conditioning relay.

It reading is incorrect:
^ Check cable between air conditioning relay terminal 4 and engine control module (ECM) # B40 for a short-circuit to supply voltage and for a short-circuit to ground.





Checking Ignition Spark Cylinders 3, 4, 5 and 6
- Ignition OFF.
- Disconnect all injectors.
- Disconnect ignition coils for cylinders 3, 4, 5 and 6.
- Install new spark plugs in ignition coils.
- Place the spark plugs against the engine.
- Operate starter motor.
- Check for a spark on the spark plugs.

If reading is OK:
^ The fault is intermittent. Fault-trace.

If reading is incorrect:
^ Proceed to: Check section below.

Check
- If there is no spark:
- cylinder 3 select 1
- cylinder 4 select 2
- cylinder 5 select 3
- cylinder 6 select 4

- Select an alternative.

Alternative 1:
^ Proceed to: Checking Cylinder 3 Signal Cable section below.

Alternative 2:
^ Proceed to: Checking Cylinder 4 Signal Cable section below.

Alternative 3:
^ Proceed to: Checking Cylinder 5 Signal Cable section below.

Alternative 4:
^ Proceed to: Checking Cylinder 6 Signal Cable section below.





Checking Cylinder 3 Signal Cable
- Ignition OFF.
- Disconnect connector from ignition discharge module (IDM) 4/38 (front).
- Ignition ON.
- Connect an electrician's screwdriver (3 W bulb at least) between ignition discharge module connector terminal 7 and ground.
- The bulb should not light.

If reading is OK:
^ Try a new ignition discharge module.

If reading is incorrect:
^ Check cable between ignition discharge module 4/38 terminal 7 and engine control module # B14 for a short-circuit to supply voltage.





Checking Cylinder 4 Signal Cable
- Ignition OFF.
- Disconnect connector from ignition discharge module 4/39 (rear).
- Ignition ON.
- Connect an electrician's screwdriver (3 W bulb at least) between ignition discharge module connector terminal 7 and ground.
- The bulb should not light.

If reading is OK:
^ Try a new ignition discharge module.

If reading is incorrect:
^ Check cable between ignition discharge module 4/39 terminal 7 and engine control module # B35 for a short-circuit to supply voltage.





Checking Cylinder 5 Signal Cable
- Ignition OFF.
- Disconnect connector from ignition discharge module 4/38 (front).
- Ignition ON.
- Connect an electrician's screwdriver (3 W bulb at least) between ignition discharge module connector terminal 5 and ground.
- The bulb should not light.

If reading is OK:
^ Try a new ignition discharge module.

If reading is incorrect:
^ Check cable between ignition discharge module 4/38 terminal 5 and engine control module # B10 for a short-circuit to supply voltage.





Checking Cylinder 6 Signal Cable
- Ignition OFF.
- Disconnect connector from ignition discharge module 4/39 (rear).
- Ignition ON.
- Connect an electrician's screwdriver (3 W bulb at least) between ignition discharge module connector terminal 2 and ground.
- The bulb should not light.

It reading is OK:
^ Try a new ignition discharge module.

If reading is incorrect:
^ Check cable between ignition discharge module 4/39 terminal 2 and engine control module # B34 for a short-circuit to supply voltage.

Fault-tracing Information
Fault-tracing for this diagnostic test is not followed by a verification.

- Do you want to repeat the fault-tracing for this diagnostic test?

Yes:
^ Proceed to: Checking Air Conditioning Relay section above.

No:
^ Fault corrected.