Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0134, P0154 [AJ] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S related) been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE OR STORED DTCs NOTE: If fuel monitor DTC, DTC P0131, P0132, P0151 or P0152 is retrieved, ignore it until P0134 or P0154 is fixed. Turn ignition switch to OFF, then ON (Engine off). Verify pending code or stored DTCs using the WDS or equivalent. Is other DTC present?	Yes	Go to appropriate DTC troubleshooting procedures. (See DTC TABLE .)
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA Is DTC P0134 or P0154 on FREEZE FRAME DATA?	Yes	Go to the next step.
4		No	Go to troubleshooting procedures for DTC on FREEZE FRAME DATA. (See DTC TABLE .)
5	VERIFY CURRENT INPUT SIGNAL STATUS Warm up engine. Access O2S11 for P0134 or O2S21 for P0154 PID using the WDS or equivalent. Verify PID when racing engine (in PARK or NEUTRAL). Is PID reading normal? 0.55 V or more when the accelerator pedal is suddenly depressed (rich condition). 0.55 V or less just after release of accelerator pedal (lean condition)	Yes	Go to step 8.
5		No	Go to the next step.
6	INSPECT INSTALLATION OF HO2S (RF, LF) Check if HO2S (RF, LF) is loosely installed. Is HO2S (RF, LF) installed securely?	Yes	Go to the next step.
6		No	Install HO2S (RF, LF) securely, then go to Step 10. (See EXHAUST SYSTEM REMOVAL/INSTALLATION .)
7	INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM Visually check if any gas leakage is found between exhaust manifold and HO2S (RF, LF). (See EXHAUST SYSTEM INSPECTION .) Is there gas leakage?	Yes	Repair or replace any faulty exhaust parts, then go to Step 10. (See EXHAUST SYSTEM REMOVAL/INSTALLATION .)
7		No	Inspect the following harnesses for open or short to GND, repair or replace harness if necessary: HO2S (RF) terminal A (harness-side) to PCM terminal 18 (harness-side) HO2S (LF) terminal A (harness-side) to PCM terminal 19 (harness-side) Repair or replace harness if necessary. If all items above are normal, replace faulty sensor. Then go to Step 10.
8	INSPECT SEALING OF ENGINE COOLANT PASSAGE WARNING: Removing radiator cap when radiator is hot is dangerous. Scalding coolant and steam may shoot out and cause serious injury. When removing radiator cap, wrap a thick cloth around and turn it slowly. Remove radiator cap. Implement procedure to bleed air from engine coolant, then run engine at idle. Are there any small bubbles, which make engine coolant white at filling opening? NOTE: Large bubbles are normal since they are remaining air coming out from engine coolant passage.	Yes	Air gets in from poor sealing on head gasket or other areas between combustion chamber and engine coolant passage. Repair or replace faulty parts, then go to Step 10.
8		No	Go to the next step.
9	INSPECT ENGINE COMPRESSION Inspect engine compression. (See COMPRESSION INSPECTION .) Is it normal?	Yes	Go to the next step.
9		No	Implement engine overhaul for repairs, then go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P0134 or P0154 COMPLETED Make sure to reconnect all disconnected connectors. Turn the ignition switch to the ON position. Clear the DTC from the memory using the WDS or equivalent. Start engine. Run Drive Mode 1 and 3. Is PENDING CODE same as DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
11		No	Troubleshooting completed.