DTC P0134 [LF, L3]


DTC P0134	Front HO2S no activity detected
DETECTION CONDITION	• The PCM monitors the input voltage from the front HO2S when the following conditions are met. If the input voltage from the sensor never exceeds 0.55 V for 83.2 s, the PCM determines that sensor circuit is not activated. MONITORING CONDITIONS - HO2S, HO2S heater and TWC Repair Verification Drive Mode - Following conditions are met • Engine speed is above 1,500 rpm. • Engine coolant temperature is above 70 °C {158 °F}. Diagnostic support note • This is a continuous monitor (HO2S). • The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. • PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. • FREEZE FRAME DATA is available. • DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Front HO2S deterioration • Front HO2S heater malfunction • Leakage exhaust system • Open circuit or short to ground in wiring harness t between front HO2S terminal A and PCM terminal 2AG • Insufficient compression • Engine malfunction


STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related service 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 AND STORED DTC Note • If fuel monitor DTC, DTC P0132 is retrieved, ignore it until P0134 is fixed. • Turn the ignition switch off, then to the ON position (Engine off). • Verify pending and stored DTCs using the WDS or equivalent. • Is other DTC present?	Yes	Go to the appropriate DTC troubleshooting procedures.
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P0134 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 [LF, L3].)
5	VERIFY CURRENT INPUT SIGNAL STATUS • Warm up engine. • Access O2S11 PID using WDS or equivalent. • Verify PID while racing engine in NEUTRAL. • Is PID normal? - More than 0.55 V when suddenly depressing accelerator pedal (rich condition) - Less than 0.55 V just after releasing the of accelerator pedal (lean condition)	Yes	Go to step 8.
5		No	Go to the next step.
6	INSPECT INSTALLATION OF FRONT HO2S • Inspect if the front HO2S is loosely installed. • Is the sensor installed securely?	Yes	Go to the next step.
6		No	Install sensor securely, then go to Step 10.
7	INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM • Visually inspect if the re is any gas leakage between the exhaust manifold and front HO2S. • Is there gas leakage?	Yes	Repair or replace any malfunctioning exhaust part, then go to Step 10.
7		No	• Inspect the following harnesses for open circuit or short to ground, repair or replace wiring harness if necessary. - Front HO2S terminal A (wiring harness-side) to PCM terminal 2AG (wiring harness-side) • Repair or replace wiring harness if necessary. • If all items above are normal, replace malfunctioning sensor. Then go to Step 10.
8	INSPECT SEALING OF ENGINE COOLANT PASSAGE • Perform the ENGINE COOLANT LEAKAGE INSPECTION. (See ENGINE COOLANT LEAKAGE INSPECTION.) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to inspection results, then go to Step 10.
8		No	Go to the next step.
9	INSPECT ENGINE COMPRESSION • Inspect engine compression. (See COMPRESSION INSPECTION [LF, L3].) • Is it normal?	Yes	Go to the next step.
9		No	Perform engine overhaul for repairs, then go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P0134 COMPLETED • Make sure to reconnect all disconnected connectors. • Turn the ignition switch to the ON position (Engine off). • Clear the DTC from memory using the WDS or equivalent. • Perform the HO2S heater, HO2S, and TWC Repair Verification Drive Mode. (See OBD DRIVE MODE [LF, L3].) • Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [LF, L3].)
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE • Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE [LF, L3].) • Are any DTC present?	Yes	Go to the applicable DTC troubleshooting. (See DTC TABLE [LF, L3].)
11		No	Troubleshooting completed.