Wiring Diagram:
Courtesy of SUBARU OF AMERICA, INC. DIAGNOSTIC PROCEDURE (DTC P1153)
| Step |
Check |
Yes |
No |
1
CHECK FOR ANY OTHER DTC ON DISPLAY. |
Is any other DTC displayed? |
Inspect the relevant DTC using "List of Diagnostic Trouble Code (DTC)". < Ref. to
, LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . > |
Go to step 2. |
2
CHECK FRONT OXYGEN (A/F) SENSOR DATA.
- Start engine.
- While observing the Subaru Select Monitor or OBD-II general scan tool screen, warm-up the engine until coolant temperature is above 75°C (167°F).
If the engine is already warmed-up, operate at idle speed for at least 1 minute.
- Read data of front oxygen (A/F) sensor signal using Subaru Select Monitor or OBD-II general scan tool.
NOTE:
- Subaru Select Monitor
For detailed operation procedure, refer to the "READ CURRENT DATA FOR ENGINE". < Ref. to
, SUBARU SELECT MONITOR . >
- OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II general scan tool instruction manual .
|
Is the measured value within 0.86 - 1.15 at idle? |
Go to step 3. |
Go to step 4. |
3
CHECK REAR OXYGEN SENSOR SIGNAL.
- Race engine at speeds from idling to 5,000 rpm for a total of 5 cycles.
NOTE:
To increase engine speed to 5,000 rpm, slowly depress accelerator pedal, taking approximately 5 seconds, and quickly release accelerator pedal to decrease engine speed.
- Operate the LED operation mode for engine.
NOTE:
- Subaru Select Monitor
For detailed operation procedure, refer to the "LED OPERATION MODE FOR ENGINE".
< Ref. to
, SUBARU SELECT MONITOR . >
|
Does the LED of {Rear O2 Rich Signal} blink? |
Check front oxygen (A/F) sensor circuit. |
Check rear oxygen sensor circuit.
< Ref. to
REAR OXYGEN SENSOR
. > |
4
CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following items.
- Loose installation of portions
- Damage (crack, hole etc.) of parts
- Looseness of front oxygen (A/F) sensor
- Looseness and ill fitting of parts between front oxygen (A/F) sensor and rear oxygen sensor
|
Is there any fault in exhaust system? |
Repair or replace faulty parts. |
Replace front oxygen (A/F) sensor.
< Ref. to
FRONT OXYGEN (A/F) SENSOR
. > |