Mazda CX-7 2007 Workshop Manual page 130

DTC P0138[L3 WITH TC]
DTC P0138 Rear HO2S circuit high input
• The PCM monitors the input voltage from the rear HO2S. If the input voltage from the rear HO2S sensor is
above 1.2 V for 0.8 s, the PCM determines that the circuit input is high.
Diagnostic support note
• This is an intermittent monitor (HO2S).
DETECTION
• The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or
CONDITION
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.
• DTCs are stored in the PCM memory.
• Rear HO2S malfunction
• Short to power supply in the wiring harness between rear HO2S terminal A and PCM terminal 2Q
POSSIBLE
• Rear HO2S or PCM terminal shorted
CAUSE
• PCM malfunction
REAR HO2S
REAR HO2S
WIRING HARNESS-SIDE CONNECTOR
01-02–88
ON-BOARD DIAGNOSTIC [L3 WITH TC]
5
A
B
1BE 1BA 1AW 1AS 1AO 1AK 1AG 1AC 1Y 1U 1Q 1M
A C
1BF 1BB 1AX 1AT 1AP 1AL 1AH 1AD 1Z 1V 1R 1N
B D
1BG 1BC 1AY 1AU 1AQ 1AM 1AI 1AE 1AA 1W 1S 1O
1BH 1BD 1AZ 1AV 1AR 1AN 1AJ 1AF 1AB 1X
2BE 2BA 2AW 2AS 2AO 2AK 2AG 2AC 2Y 2U 2Q 2M
2BF 2BB 2AX 2AT 2AP 2AL 2AH 2AD 2Z 2V 2R 2N
2BG 2BC 2AY 2AU 2AQ 2AM 2AI 2AE 2AA 2W 2S 2O
2BH 2BD 2AZ 2AV 2AR 2AN 2AJ 2AF 2AB 2X 2T 2P
PCM
2Q
1BC
PCM
WIRING HARNESS-SIDE CONNECTOR
id010239805100
1I 1E 1A
1J 1F 1B
1K 1G 1C
1T 1P 1L 1H 1D
2I 2E 2A
2J 2F 2B
2K 2G 2C
2L 2H 2D