DTC P0138:00 [L8, LF, L5]

id010242702600

DTC P0138:00

HO2S circuit high input

DETECTION CONDITION

•  The PCM monitors input voltage from HO2S. If the input voltage from the HO2S is above 1.2 V for 0.8 s, the PCM determines that circuit input is high.

Diagnostic support note

•  This is a continuous monitor (A/F sensor, HO2S).

•  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.

•  The DTC is stored in the PCM memory.

POSSIBLE CAUSE

•  HO2S malfunction

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

•  HO2S or PCM terminal shorted

•  PCM malfunction

DTC P0138:00	HO2S circuit high input
DETECTION CONDITION	• The PCM monitors input voltage from HO2S. If the input voltage from the HO2S is above 1.2 V for 0.8 s, the PCM determines that circuit input is high. Diagnostic support note • This is a continuous monitor (A/F sensor, HO2S). • 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. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• HO2S malfunction • Short to power supply in wiring harness between HO2S terminal A and PCM terminal 2Q • HO2S or PCM terminal shorted • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME on the 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	VERIFY RELATED PENDING OR STORED DTC • Switch the ignition to off, then to the ON. (Engine off) • Verify pending code or stored DTCs using the M-MDS. • Are other DTCs present?	Yes	Go to the appropriate DTC troubleshooting procedures. (See DTC TABLE [L8, LF, L5].)
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is the DTC P0138:00 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 [L8, LF, L5].)
5	INSPECT HO2S SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • Switch the ignition to off. • Disconnect HO2S connector. • Switch the ignition to ON. (Engine off) • Measure the voltage between HO2S terminal A (wiring harness-side) and body ground. • Is the voltage B+?	Yes	Replace a short to power supply, then go to Step 7.
5		No	Go to the next step.
6	INSPECT HO2S • Inspect the HO2S. (See AIR FUEL RATIO (A/F) SENSOR, HEATED OXYGEN SENSOR (HO2S) INSPECTION [L8, LF, L5].) • Is HO2S normal?	Yes	Go to the next step.
6		No	Replace the HO2S, then go to the next step. (See AIR FUEL RATIO (A/F) SENSOR, HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [L8, LF, L5].)
7	VERIFY TROUBLESHOOTING OF DTC P0138:00 COMPLETED • Make sure to reconnect all disconnected connectors. • Switch the ignition to ON. (Engine off) • Clear the DTC from the memory using the M-MDS. • Perform the KOEO or KOER self-test. (See KOEO/KOER SELF TEST [L8, LF, L5].) • Is the DTC P0138:00 present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L8, LF, L5].)
7		No	Go to the next step.
8	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L8, LF, L5].) • Are any DTC present?	Yes	Go to the applicable DTC troubleshooting. (See DTC TABLE [L8, LF, L5].)
8		No	Troubleshooting completed.