DTC P0691 COOLING FAN 1 CONTROL CIRCUIT LOW
DTC P0691 COOLING FAN 1 CONTROL CIRCUIT LOW |
DTC DETECTING CONDITION:
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Two consecutive driving cycles with fault
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GENERAL DESCRIPTION
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TROUBLE SYMPTOM:
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Radiator fan does not operate properly.
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Overheating
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Important | ||
After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode . |
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WIRING DIAGRAM:
CHECK OUTPUT SIGNAL FROM ECM.
Turn the ignition switch to OFF.Connect the test mode connector.
Turn the ignition switch to ON.
While operating the radiator fan relay, measure voltage between ECM terminal and ground.
Note | ||
Radiator fan relay operation can be executed using Vehicle Diagnostic Interface. For procedure, refer to “Compulsory Valve Operation Check Mode”. |
Connector & terminal
(B84) No. 17 (+) — Chassis ground (−):
(B84) No. 28 (+) — Chassis ground (−):
Does the voltage change 0 — 10 V?
Yes |
Repair poor contact in ECM connector.
No |
CHECK GROUND SHORT CIRCUIT IN RADIATOR FAN RELAY CONTROL CIRCUIT.
Turn the ignition switch to OFF.Disconnect the connectors from ECM.
Measure the resistance of harness between ECM connector and chassis ground.
Connector & terminal
(B84) No. 17 — Chassis ground:
(B84) No. 28 — Chassis ground:
Is the resistance more than 1 MΩ?
Yes |
No |
Repair ground short circuit in radiator fan relay control circuit.
CHECK POWER SUPPLY FOR RELAY.
Remove the main fan relay 1 and main fan relay 2 from A/C relay holder.Turn the ignition switch to ON.
Measure the voltage between fuse and relay box (F/B) connector and chassis ground.
Connector & terminal
(F27) No. 27 (+) — Chassis ground (−):
(F27) No. 32 (+) — Chassis ground (−):
Is the voltage more than 10 V?
Yes |
No |
Repair open circuit in harness between ignition switch and fuse and relay box (F/B) connector.
CHECK MAIN FAN RELAY.
Turn the ignition switch to OFF.Measure the resistance between main fan relay terminals.
Terminals
No. 32 — No. 34: (Main fan relay 1)
No. 25 — No. 27: (Main fan relay 2)
Is the resistance 87 — 107 Ω?
Yes |
No |
Replace the main fan relay.
CHECK OPEN CIRCUIT IN MAIN FAN RELAY CONTROL CIRCUIT.
Measure the resistance of harness between ECM and fan relay connector.Connector & terminal
(B84) No. 17 — (F27) No. 32:
(B84) No. 28 — (F27) No. 27:
Is the resistance less than 1 Ω?
Yes |
No |
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Repair harness and connector.
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CHECK POOR CONTACT.
Check poor contact in ECM or fan relay connector.Is there poor contact in ECM or fan relay connector?
Yes |
Repair poor contact in ECM or fan relay connector.
No |
Contact Service Center.