

Diagnostic procedure


Dtc p2503
TroubleshootingMazda 6 Service Manual: Mechanical system test
Mechanical System Test Preparation
1. Engage the parking brake and use wheel chocks at the front and rear of the
wheels.
2. Inspect the engine coolant. (See ENGINE COOLANT LEVEL INSPECTION.)
3. Inspect the engine oil. (See ENGINE OIL INSPECTION.)
4. Inspect the ATF levels. (See AUTOMATIC TRANS ...
Mazda 6 Service Manual: Three-way catalytic converter (twc) inspection
Note
Make sure that no HO2S DTCs have been detected. If detected, this
inspection is not applicable for TWC inspection.
1. Connect the WDS or equivalent and monitor PIDs as following.
Monitor the right TWC using O2S11 PID for upstream HO2S and O2S12 PID
for downstream HO2S.
2. Be ...