F23A1/F23A5

DTC P1486: Range/Performance Problem in Thermostat

NOTE: If the DTCs listed below are stored at the same time as DTC P1486, troubleshoot those DTCs first, then recheck for P1486.

P0107, P0108, P1128, P1129: MAP Sensor
P1106, P1107, P1108: Barometric Pressure Circuit
P1253, P1257, P1258, P1259: VTEC system
P0401: EGR Flow Insufficient
P1491: EGR Valve Lift Insufficient
P1498: EGR Valve Lift Sensor High Voltage
P0116, P0117, P0118: Engine Coolant Temperature Circuit
P0112, P0113: Intake Air Temperature Circuit
P0500: Vehicle Speed Sensor
P0335, P0336, P1359: Crankshaft Position Sensor
P0300, P1399: Random Misfire
P0301, P0302, P0303, P0304: Cylinder 1,2,3 or 4 Misfire
detected.
P0505: Idle Control System Malfunction
P1519: Idle Air Control Valve

DTC P1486 can set occasionally when the hood is opened.
1. Check the engine coolant level. Is the engine coolant level low?
NO-Go to step 2.
YES-Refill the engine coolant. If necessary, check the cooling system.
2. Turn the ignition switch ON (II).
3. Check the radiator fan.
Does the radiator fan keep running?
YES-Check the radiator fan circuit with A/C model or without A/C model, radiator fan switch circuit, and the radiator fan switch.
It they are OK, substitute the ECM/PCM and recheck.
Diagnostic Strategies

If the symptom/indication goes away, replace the original ECM/PCM.
NO-Test the thermostat.