13A-19
MPI – TROUBLESHOOTING
Check the operation of the inter-
cooler water spray
• Ignition switch: ON
• Inter-cooler water spray
switch (manual): ON
OK: Inter-cooler water spray
operates
Check the operation of the inter-
cooler water spray
• Undo the engine ECU
connector C-50, and earth
terminal 56.
• Ignition switch: ON
OK: Inter-cooler water spray
operates
Check connector: C-220
Check the inter-cooler water
spray relay (Refer to Section 15:
Intake/Exhaust)
Go on to the next page
Measure at the inter-cooler water
spray switch connector D-32
• Undo the connector and
measure on the harness side
• Ignition switch: ON
•Voltage across earth at 5
OK: battery voltage
Check connectors: C-22 & C-50
Check connector: D-32
Inspect the harness between the
engine ECU and the inter-cooler
water spray switch
• Check if the signal wire is cut
or has short circuited
Replace the engine ECU
Check connectors: C-22 & C-50
Measure at the inter-cooler water
spray switch connector D-32
• Undo the connector and
measure on the harness side
• Ignition switch: ON
•Voltage across earth at 3 & 5
OK: battery voltage
Replace the inter-cooler water
spray relayReplace engine ECU
Check the inter-cooler water
spray switch (Ref Section 15:
Intake/Exhaust)
Inspect the harness between the
inter-cooler water spray switch
and the engine ECU
• Check if the signal wire is
damaged
Temporary malfunction (Ref
Section 00: Dealing with
temporary malfunctions)
Check connector: D-32
Check the inter-cooler water
spray switch
(Ref Section 15: Intake/Exhaust)
Check connector: C-107
Replace the inter-cooler water
spray relayInspect the harness
between the inter-cooler water
spray switch and earth
• Check if the earth wire is cut
or damaged
Inspect the harness between the
inter-cooler water spray switch
and the engine ECU, repair if
necessary
• Check if the signal wire is
damaged
Inspect the harness between the
engine ECU and the inter-cooler
water spray switch
• Check if the signal wire is cut
or has short circuited
OK
NG
NG
OK
NG
NG
OK
OK
OK
OK
NG
OK
OK
NG
NG
Repair
Inspection procedure 35
Inter-cooler water spray circuit system Probable causes of the malfunction
• If the inter-cooler water spray switch (manual) is turned ON, the inter-cooler
water spray manual ‘ON’ signal will be input in the engine ECU. When this
signal is received, the engine ECU will turn the inter-cooler water spray relay
ON, and will start the inter-cooler water spray motor. Water will be sprayed
into the inter-cooler to cool intake air, and filling efficiency will improve.
• If the inter-cooler water spray switch (auto) is turned ON, the inter-cooler
water spray auto ‘ON’ signal will be input in the engine ECU. When this
signal is received the engine ECU will intermittently run at a high load, it will
turn the inter-cooler water spray relay ON, and it will start the inter-cooler
water spray motor. Water will be sprayed into the inter-cooler to cool intake
air, and filling efficiency will improve.
• Malfunction of the inter-cooler water
spray switch.
• Malfunction of the inter-cooler water
spray relay.
• Malfunction of the inter-cooler water
spray motor.
• Circuit break, short circuit or a faulty
connection in the inter-cooler water
spray relay circuit.
• Circuit break, short circuit or a faulty
connection in the inter-cooler water
spray switch circuit.
•Malfunction of the ignition switch.
• Malfunction of the engine ECU.
Replace the engine ECU
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
OK
NG
Repair
Repair
