1A-98 Engine General Information and Diagnosis:
Step
8
Air intake system check
1) Check air intake system for clog or leak.
Is it OK?
DTC P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-2)
Wiring Diagram
GRN
3
WHT
1
11
15
14
13
12
11
30
28
27
26
29
45
44
43
42
41
59
60
58
57
56
1. Main fuse box
2. Shield wire
3. Ignition switch
DTC Detecting Condition and Trouble Area
DTC P0137:
HO2S-2 voltage is lower than specified value while engine is idling after driving with
high engine load (high speed) for specified time. And HO2S-2 max. voltage minus
HO2S-2 min. voltage is less than specified value for 40 sec.
(2 driving cycle detection logic)
DTC P0138:
HO2S-2 voltage is higher than specified value while engine is idling after driving with
high engine load (high speed) for specified time. And HO2S-2 max. voltage minus
HO2S-2 min. voltage is less than specified value for 40 sec.
(2 driving cycle detection logic)
Action
4
BLK/WHT
5
BLK
WHT
8
12
E01
10
9
8
7
6
5
4
3
25
24
23
22
21
20
19
18
40
39 38
37
36
35
34
33
55
54 53
52
51
50
49
48
4. Junction block assembly
5. "IG COIL" fuse
6. HO2S-2
DTC detecting condition
Replace HO2S-1
referring to "Heated
Oxygen Sensor (HO2S-
1 and HO2S-2)
Removal and
Installation (If Equipped)
in Section 1C".
If DTC still exists,
substitute a known-
good ECM and recheck.
6
BLK
7
2
BLU
BRN
ORN
2
1
15
14
13
12
11
17
16
30
28
27
26
29
32 31
45
44
43
42
41
59
47 46
60
58
57
56
7. Heater
8. To HO2S-1 heater
9. ECM
Yes
Repair or replace air
intake system.
9
BLK/WHT
E01-29
RED/BLU
C01-47
5V
C01-11
C01-57
10
C01
10
9
8
7
6
5
4
3
25
24
23
22
21
20
19
18
40
39 38
37
36
35
34
33
55
54 53
52
51
50
49
48
10. To HO2S-1
11. Individual circuit fuse box No.1
12. "IG ACC" fuse
Trouble area
• HO2S-2
• HO2S-2 circuit
• Fuel system
• ECM
• Fuel shortage
• Exhaust system
• Air intake system
No
S7RW0A1104036
2
1
17
16
32 31
47 46
I6RW0D110028-01