DTC P0054

DTC P0054	HO2S heater resistance
DETECTION CONDITION	The PCM monitors the HO2S heater resistance when under the HO2S heater control. If the resistance is more than 107.27 ohms or less than 9.39 ohms for 5s , the PCM determines that there is a HO2S heater circuit problem. Diagnostic support note This is a intermittent monitor (A/F sensor heater, HO2S heater). 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 the first drive cycle. FREEZE FRAME DATA (Mode 2/Mode 12) is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	HO2S connector or terminals malfunction HO2S heater malfunction Short to ground or open circuit in HO2S heater power supply circuit Short to ground in wiring harness between ignition switch and HO2S terminal C ENG 20 A fuse malfunction Open circuit in wiring harness between ignition switch and HO2S terminal C Short to ground between HO2S terminal O and PCM terminal 2BE PCM connector or terminals malfunction Open circuit between HO2S terminal D and PCM terminal 2BE PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (Mode 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor heater, HO2S heater related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line 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	INSPECT HO2S CONNECTOR CONDITION Switch the ignition to off. Disconnect the HO2S connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal and/or connector, then go to Step 9.
3		No	Go to the next step.
4	INSPECT HO2S HEATER Inspect the HO2S heater. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION ). Is there any malfunction?	Yes	Replace the HO2S, then go to Step 9. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION ).
4		No	Go to the next step.
5	INSPECT HO2S HEATER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND HO2S connector is disconnected. Switch the ignition to ON (engine off). Measure the voltage between HO2S terminal C (wiring harness-side) and body ground. Is the voltage B+?	Yes	Go to the next step.
5		No	Repair or replace the wiring harness for a possible short to ground or open circuit, then go to Step 9.
6	INSPECT HO2S HEATER CONTROL CIRCUIT FOR SHORT TO GROUND HO2S connector is disconnected. Switch the ignition to off. Inspect for continuity between HO2S terminal D (wiring harness-side) and body ground. Is there continuity?	Yes	If the short to ground circuit could be detected: Repair or replace the wiring harness for a possible short to ground. If the short to ground circuit could not be detected: Replace the PCM (short to ground in PCM internal circuit). (See PCM REMOVAL/INSTALLATION ). Go to Step 9.
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR CONDITION Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal and/or connector, then go to Step 9.
7		No	Go to the next step.
8	INSPECT HO2S CIRCUIT FOR OPEN CIRCUIT HO2S and PCM connectors are disconnected. Inspect for continuity between HO2S terminal D (wiring harness-side) and PCM terminal 2BE (wiring harness-side). Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9	VERIFY DTC TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Switch the ignition to ON (engine off). Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE ). Perform the KOEO or KOER self test (using M-MDS) or Drive Mode 03 (PCM Adaptive Memory Production, EGR System, A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S, and TWC Repair Verification Drive Mode) (not using M-MDS). (See KOEO/KOER SELF TEST ). (See OBD-II DRIVE MODE ). Is the PENDING CODE for this 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 inspection. (See DTC TABLE ).
10		No	DTC troubleshooting completed.