DTC P0138:00 [ZY, Z6]

id0102c7702600

DTC P0138:00

HO2S circuit high input

DETECTION CONDITION

•  If the input voltage is 1.2 V or more for 5 s or more, the PCM determines that the HO2S circuit voltage is high.

Diagnostic support note

•  This is an intermittent monitor (A/F sensor, 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 the first drive cycle.

•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

•  The DTC is stored in the PCM memory.

POSSIBLE CAUSE

•  HO2S connector or terminals malfunction

•  PCM connector or terminals malfunction

•  Short to power supply in wiring harness between HO2S terminal A and PCM terminal 2AH

•  HO2S malfunction

•  PCM malfunction

DTC P0138:00	HO2S circuit high input
DETECTION CONDITION	• If the input voltage is 1.2 V or more for 5 s or more, the PCM determines that the HO2S circuit voltage is high. Diagnostic support note • This is an intermittent monitor (A/F sensor, 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 the first drive cycle. • FREEZE FRAME DATA (Mode 2)/Snapshot data is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• HO2S connector or terminals malfunction • PCM connector or terminals malfunction • Short to power supply in wiring harness between HO2S terminal A and PCM terminal 2AH • HO2S malfunction • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT HO2S CONNECTOR AND TERMINALS • Switch the ignition to off. • Disconnect the HO2S connector. • Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). • Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 7.
3		No	Go to the next step.
4	INSPECT PCM CONNECTOR AND TERMINALS • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). • Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 7.
4		No	Go to the next step.
5	INSPECT HO2S SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • HO2S and PCM connectors are disconnected. • Switch the ignition to ON (engine off). • Measure the voltage between HO2S terminal A (wiring harness-side) and body ground. • Is there any voltage?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 7.
5		No	Go to the next step.
6	INSPECT HO2S • Switch the ignition to off. • Reconnect the HO2S and PCM connectors. • Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [ZY, Z6].) • Is there any malfunction?	Yes	Replace the HO2S, then go to the next step. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [ZY, Z6].)
6		No	Go to the next step.
7	VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [ZY, Z6].) • Perform the KOEO/KOER self test. (See KOEO/KOER SELF TEST [ZY, Z6].) • Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [ZY, Z6].)
7		No	Go to the next step.
8	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [ZY, Z6].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [ZY, Z6].)
8		No	DTC troubleshooting completed.