Heated Oxygen Sensor (Ho2S) - Honda Prelude 1993 Service Manual

PGM-FI System
Troubleshooting Flowchart - Heated Oxygen Sensor (HO2S)
SENSOR
TERMINALS
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The Heated Oxygen Sensor (HO2S) detects the oxygen content in the exhaust gas and signals the ECM. In op€ration,
the ECM receives the signals from the sensor and varies the duration during which fuel is injected. The HO25 has an
internal heater, The heater stabilizes the sensor's output. The HO2S is installed in the exhaust manifold
(H2341 engine
(USA: Si/Canada: SR). H22A1 engine (USA: Si VTEC/Csnada: SR-VI: in the exhaust pipe A)'
HEATER
TEBMINALS
The Maltunction Indicator Lamp (MlL) indicates Diagnostic Trouble code {DTC) 1: A problem in th€
Heated Oxygen Sensor (HO2S) circuit.
VOLTAGE IVI
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-
1 1 - 5 6
RICH - AIR.
- LEAI{
FUEL
RATIO
- Tha MIL hsa becn roDortod on.
- Yvlth sorvico chack connoclor
iumpod l.60 page I 142), codo
1 i3 indicatod.
Do the ECM Reset Procedure {see
p a g e 1 1 - 4 3 ) .
Warm up engine to normal oPeF
ating t€mperature (the radiator fan
comes on),
Run engine tor 60 seconds.
Road test with the manualtrqls-
mission in 4th geat I AfIt lA
position).
Starting st 1,600 rpm, accelerate
using wide open throttl€ for at
least 5 seconds. Then doceler€te
tor at least 5 seconds with the
throttle completoly closed.
Intormittont lrllur., systom l. OK
al thb time. Ch.ck to,. poot con-
noctlons o. loorc wiror at C432
{locatod al tight shock towcr),
C114 (HO2S) and ECM.
ls the MIL on and does it indi-
cate code 1?
Go !o pagl. and p€rtorm tcat for
.-.3 l-
p.fo 11-62).