DTC P0134


DTC P0134	HO2S circuit no activity detected
DETECTION CONDITION	• The PCM monitors the input voltage from the HO2S when the following conditions are met. If the input voltage from the sensor never exceeds 0.55 V for 120 s or more, the PCM determines that sensor circuit is not activated. MONITORING CONDITIONS - HO2S, HO2S heater and TWC repair verification drive mode - The Following conditions are met • The Engine speed is 1,500 rpm or more. • The Engine coolant temperature is 80 °C {176 °F} or more. • Within feed-back range Diagnostic support note • This is a continuous monitor (CCM). • 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. • The PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle. • The FREEZE FRAME DATA is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• HO2S deterioration • HO2S heater malfunction • Leakage exhaust system • Open or in the short to ground circuit between HO2S terminal A and PCM terminal 2AI • Insufficient compression • Engine malfunction


STEP	INSPECTION		ACTION
1	PERFORM DTC CONFIRMATION PROCEDURE • Perform the DTC CONFIRMATION PROCEDURE. (See DTC CONFIRMATION PROCEDURE.) • Is the same DTC present?	Yes	Go to the next step.
1		No	Intermittent concern exists. Go to the INTERMITTENT CONCERN TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING.)
2	VERIFY RELATED PENDING AND STORED DTCS Note • If a fuel monitor DTC, DTC P0131, or 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. • Are any other DTCs present?	Yes	Go to the applicable DTC troubleshooting procedures.
2		No	Go to the next step.
3	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P0134 on the FREEZE FRAME DATA?	Yes	Go to the next step.
3		No	Go to the troubleshooting procedures for the DTC on the FREEZE FRAME DATA. (See DTC TABLE.)
4	VERIFY CURRENT INPUT SIGNAL STATUS • Warm up the engine. • Access the O2S11 PID using the WDS or equivalent. • Verify the PID while racing the engine (in NEUTRAL (MTX) or PARK (ATX)). • Is the PID reading normal? - More than 0.55 V when suddenly depressing the accelerator pedal (rich condition). - Less than 0.55 V just after releasing of the accelerator pedal (lean condition)	Yes	Go to step 7.
4		No	Go to the next step.
5	INSPECT INSTALLATION OF HO2S • Check if the HO2S is loosely installed. • Is the sensor installed securely?	Yes	Go to the next step.
5		No	Install the sensor securely, then go to Step 9.
6	INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM • Visually check if any gas leakage is found between the exhaust manifold and the HO2S. • Is there any gas leakage?	Yes	Repair or replace any the malfunctioning exhaust parts, then go to Step 9.
6		No	• Inspect the following wiring harnesses for an open or short circuit to ground circuit, repair or replace the wiring harness if necessary - The HO2S terminal A (wiring harness-side) to the PCM terminal 2AI (wiring harness-side) • Repair or replace the wiring harness if necessary. • If all items above are normal, replace the malfunctioning sensor. Then go to Step 9.
7	INSPECT SEALING OF ENGINE COOLANT PASSAGE Warning • Removing the radiator cap when the radiator is hot is dangerous. Scalding coolant and steam may shoot out and cause serious injury. • When removing the radiator cap, wrap a thick cloth around it and turn it slowly. • Remove the radiator cap. • Implement the procedure to bleed air from the engine coolant, then idle engine. • Are there any small bubbles, that makes the engine coolant white at the filling opening? Note • Large bubbles are normal since they are due to remaining air coming out from the engine coolant passage.	Yes	Air gets in from poor sealing on the head gasket or other areas between the combustion chamber and engine coolant passage. Repair or replace the malfunctioning parts, then go to Step 9.
7		No	Go to the next step.
8	INSPECT ENGINE COMPRESSION • Inspect the engine compression. (See COMPRESSION INSPECTION [ZJ, ZY].) • Is it normal?	Yes	Go to the next step.
8		No	Implement the engine overhaul for repairs, then go to the next step.
9	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 KOER self-test. (See KOEO/KOER SELF-TEST.) • Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION.)
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE.) • Are any DTCs present?	Yes	Go to the applicable DTC troubleshooting. (See DTC TABLE.)
10		No	Troubleshooting completed.