MPI – Troubleshooting
13-16
Code No. 44 Ignition coil and power transistor unit system Probable cause
Range of Check
D Engine speed is approx. 50–4,000 r/min
D Engine is not cranking.
Set conditions
D Abnormal rotation due to misfire is detected by crank angle sensor (Either one
of coils fails).
D Malfunction of the ignition coil
D Improper connector contact, open or short-circuited
harness wire of the ignition primary circuit
D Malfunction of the engine-ECU
OK
OK
Check trouble symptom.
Measure at the ignition coil connectors
A-110, A-111
D Disconnect the connector, and
measure at the harness.
1. Voltage between 1 and earth
(Ignition switch: ON)
OK: System voltage
2. Voltage between 3 and earth
(Engine: Cranking)
OK: 0.5–4.0 V
3. Continuity between the 2 and earth
OK: Continuity
1. NG
Check the following connectors:
B-65, B-76
OK
Check trouble symptom.
NG
Check the harness wire between the
ignition coil and ignition switch connec-
tor, and repair if necessary.
2. NG
Check the following connector: B-59
NG
Repair
NG
Check the harness wire between the
engine-ECU and ignition coil connector.
OK
Replace the engine-ECU.
NG
Repair
3. NG
Check the harness wire between the
ignition coil connector and earth, and
repair if necessary.
Check the following connectors:
A-110, A-111
NG
Repair
Check trouble symptom.
NG
Check the following items.
D Check the spark plugs, spark plug
cables.
D Check the compression pressure.
NG
Repair
Check the ignition coil. (Refer to
GROUP 16 – IGNITION SYSTEM.)
NG
Replace
OK
OK
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