Mazda RX-8 Workshop Manual page 274

Disconnect the HO2S connector.
Inspect for poor connection (such as
damaged/pulled-out pins, corrosion).
Is there any malfunction?
INSPECT PCM CONNECTOR FOR POOR
4 CONNECTION
Turn the ignition switch off.
Disconnect the PCM connector.
Inspect for poor connection (such as
damaged/pulled-out pins, corrosion).
Is there any malfunction?
INSPECT HO2S CIRCUIT FOR SHORT TO POWER
5 SUPPLY
HO2S and PCM connectors are
disconnected.
Turn the ignition switch to the ON
position (engine off).
Measure the voltage between the
following circuits:
Is the voltage more than 1.2 V?
INSPECT HO2S
6
Inspect the HO2S.
(See HEATED OXYGEN SENSOR
(HO2S) INSPECTION
Is there any malfunction?
VERIFY TROUBLESHOOTING OF DTC P0138
7 COMPLETED
Make sure to reconnect all
disconnected connectors.
Clear the DTC from the PCM memory
using the M-MDS.
(See AFTER REPAIR PROCEDURE [13B-
MSP].)
HO2S terminal A
(wiring harness-side)
and body ground
HO2S terminal B
(wiring harness-side)
and body ground
[13B-MSP].)
No Go to the next step.
YesRepair or replace the connector and/or terminals,
then go to Step 7.
No Go to the next step.
YesRepair or replace the wiring harness for a
possible short to power supply, then go to Step
7.
No Go to the next step.
YesReplace the HO2S, then go to the next step.
(See HEATED OXYGEN SENSOR (HO2S)
REMOVAL/INSTALLATION
No Go to the next step.
YesReplace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION
No Go to the next step.
[13B-MSP].)
[13B-MSP].)