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OBD0527
BI: DTC P1500
—RADIATOR FAN RELAY 1 CIRCUIT
MALFUNCTION (FAN
—1)—
DESCRIPTION:
The engine cooling system consists of a down-flow
radiator which features high heat-dissipation performance,
an electric motor fan, an engine coolant pump, a
thermostat, and an engine coolant temperature sensor.
The ON-OFF control of the radiator fan is governed by
the ECM which receives signals sent from the engine cool-
ant temperature sensor. On models which are equipped
with an air conditioning system, the ECM receives signals
sent from the engine coolant temperature sensor, vehicle
speed sensor 2 and A/C switch. These signals simulta-
neously turn ON or OFF the radiator main fan and radiator
sub fan as well as setting them at“HI”or“LO”speed.
[Without A/C models]
Engine coolant temperature signal *1ECM output signal Operation of radiator fan
Radiator fan relay 1 Main
ON ON ON
OFF OFF OFF
*1 ON: Above 95°C (203°F), OFF: Below 89°C (192°F)
[With A/C models]
Engine coolant
temperature
signal *2A/C compressorVehicle speed
signal *3ECM output signal Operation of radiator fan
Radiator fan
relay 1Radiator fan
relay 2Main Sub
ONONON ON ON HI HI
OFF ON ON HI HI
OFFON ON ON HI HI
OFF ON OFF LO LO
OFFONON ON ON HI HI
OFF ON OFF LO LO
OFFON OFF OFF OFF OFF
OFF OFF OFF OFF OFF
*2 ON: Above 95°C (203°F), OFF: Below 89°C (192°F)
*3 ON: Above 20 km/h (12 MPH), OFF: Below 10 km/h (6 MPH)
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DTC DETECTING CONDITION:
Two consecutive trips with fault
TROUBLE SYMPTOM:
Radiator fan does not operate properly.
Overheating
1.Check output signal from ECM.
2.Check power supply for relays.
3.Check main fan relay 1, sub fan relay 1 and
main fan relay.
4.Check harness connector.
5.Check harness connector.
6.Check monitor line.
Check radiator fan function problem.
P1502 [T11BJ0]”.>
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODE.
[T3D0] and [T3E0].>
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WIRING DIAGRAM:
LHD model
OBD0528
WIRING DIAGRAM:
RHD model
B2M0460
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OBD0736A
1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to OFF.
2) Connect test mode connector at the lower portion of
instrument panel (on the driver’s side), to the side of the
center console box.
3) Turn ignition switch to ON.
OBD0674A
4) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 77—Body/10 V, or more and 1 V
or less at every 2 seconds
: Go to step 6.
: Go to next.
OBD0534A
: Connector & terminal
(B84) No. 88—Body/10 V, or more
: Go to step 5.
: Go to step 2.
2
CHECK POWER SUPPLY FOR RELAYS.
Turn ignition switch to OFF.
: Is the fuse in power supply circuit broken?
: Replace the fuse.
: Go to step 3.
OBD0535
3CHECK MAIN FAN RELAY 1, SUB FAN RELAY
1 AND MAIN FAN RELAY.
1) Remove main fan relay 1. (With A/C models only)
2) Measure resistance between main fan relay 1 termi-
nals.
: Terminal
No. 1—No. 3/97±10Ω
: Go to next step.
: Replace main fan relay 1.
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OBD0536
3) Remove sub fan relay 1. (With A/C models only)
Remove main fan relay. (Without A/C models only)
4) Measure resistance between sub fan relay 1 or main
fan relay terminals.
: Terminal
No. 1—No. 3/100±17Ω
: Go to step 4.
: Replace sub fan relay 1 or main fan relay.
OBD0530A
4
CHECK HARNESS CONNECTOR.
1) Disconnect connector from ECM.
2) Disconnect connector from sub fan relay 1 or main fan
relay.
3) Check if the harness connector is open circuit or has
poor contact with the following circuits.
: Connector & terminal
(B84) No. 88—(F28) No. 3 / 10Ω, or less
NOTE:
With A/C models only.
: Go to next.
: Repair open circuit of harness between ECM con-
nector and main fan relay 1 connector.
: Is there poor contact in ECM or main fan
relay 1 connector?
: Repair ECM or main fan relay 1 connector.
: Go to next.
OBD0531A
: Connector & terminal
(B84) No. 88—(F40) No. 4 / 10Ω, or less
: Go to next.
: Repair open circuit of harness between ECM con-
nector and sub fan relay 1 (with A/C models) or
main fan relay (without A/C models) connector.
: Is there poor contact in ECM or sub fan
relay 1 (with A/C models) or main fan relay
(without A/C models) connector?
: Repair ECM or sub fan relay 1 (with A/C models)
or main fan relay (without A/C models) connector.
: Go to next.
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OBD0686A
: Connector & terminal
(F28) No. 1—(B72) No. 5 / 10Ω, or less
: Go to next.
: Repair open circuit of harness between main fan
relay 1 connector and ignition switch connector.
: Is there poor contact in main fan relay 1 or
ignition switch connector?
: Repair main fan relay 1 or ignition switch connec-
tor.
: Go to next.
NOTE:
With A/C models only.
OBD0687A
: Connector & terminal
(B52) No. 4—(B72) No. 2 / 10Ω, or less
: Go to next.
: Repair open circuit of harness between sub fan
relay 1 (with A/C models) or main fan relay (with-
out A/C models) connector and ignition switch
connector.
: Is there poor contact in sub fan relay 1 (with
A/C models) or main fan relay (without A/C
models) or ignition switch connector?
: Repair sub fan relay 1 (with A/C models) or main
fan relay (without A/C models) or ignition switch
connector.
: Replace ECM with a new one.
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OBD0534A
5
CHECK HARNESS CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove main fan relay 1 and sub fan relay 1. (with A/C
models)
Remove main fan relay. (without A/C models)
3) Disconnect test mode connector.
4) Turn ignition switch to ON.
5) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 88—Body / 10 V, or more
: Repair short circuit of harness and replace ECM.
: Go to next.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Replace ECM.
OBD0674A
6
CHECK MONITOR LINE.
1) Turn ignition switch to OFF.
2) Connect test mode connector.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 77—Body / 10 V, or more and 1
V, or less at every 2
seconds.
: Repair poor contact in ECM connector.
: Repair open circuit of harness between ECM con-
nector and sub fan relay 1 (with A/C models) or
main fan relay (without A/C models).
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OBD0538
BJ: DTC P1502
—RADIATOR FAN FUNCTION PROBLEM
(FAN
—F)—
DESCRIPTION:
Refer to“BI: DTC P1500—RADIATOR FAN RELAY 1
CIRCUIT MALFUNCTION—[T11BI0]”.
DTC DETECTING CONDITION:
Two consecutive trips with fault
TROUBLE SYMPTOM:
Occurrence of noise
Overheating
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