Honda 2004 Odyssey Service Manual page 426

DTC P0128 '02-04 Models:
Malfunction
NOTE: If the DTCs listed below are stored at the same
time as DTC P0128, troubleshoot those DTCs first, then
recheck for P0128.
P0107, P0108, P1128, P1129: Manifold Absolute
Pressure (MAP) sensor
P1106, P1107, P1108: Barometric Pressure (BARO)
sensor
P1259: VTEC system
P0401, P1491, P1498: Exhaust Gas Recirculation (EGR)
system
P0116, P0117, P0118: Engine Coolant Temperature
(ECT) sensor
P0112, P0113: Intake Air Temperature (IAT) sensor
P0335, P0336: Crankshaft Position (CKP) sensor
P0300: Random misfire
P0301, P0302, P0303, P0304, P0305, P0306: No. 1, No. 2,
No. 3, No. 4, No.5 or No. 6 cylinder misfire
P0505: Idle Control System Malfunction
P1519: Idle Air Control (IAC) valve
DTC P0128 can occasionally set when the hood is
opened while the engine is running.
Cooling System
1. Turn the ignition switch ON (II).
2. Make sure the A/C off.
3. Check the radiator fan.
Does the radiator f an keep running?
YES Check the radiator fan circuit
(see page 10-22), the radiator fan switch circuit (see
page 10-22), and the radiator fan switch (see page
10-22). If they are OK, substitute a known-good
PCM and recheck (see page 11-5). If the symptom/
indication goes away, replace the original PCM.
NO Go to step 4.
4. Clear the DTC with the HDS.
5. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on.
Is DT C P0128 indicated?
YES Test the thermostat (see page 10-11).
NO Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the radiator fan sensor and the PCM.
11-117