2020 Subaru Ascent BaseFACTORY OEM SERVICE PROCEDURE

Inspection Mode H

DTC Item Condition Number of driving cycles on the detecting condition
P0071 AMBIENT AIR TEMPERATURE SENSOR CIRCUIT "A" RANGE/PERFORMANCE
  • 6 hours or more have elapsed since ignition switch is OFF under a completely warmed up condition.
  • For models with block heater, at least 6 hours must have elapsed without operating the block heater.
 2
P0116 ENGINE COOLANT TEMPERATURE SENSOR 1 CIRCUIT RANGE/PERFORMANCE 2
P0196 ENGINE OIL TEMPERATURE SENSOR "A" RANGE/PERFORMANCE 2
P050A COLD START IDLE CONTROL SYSTEM PERFORMANCE - 2
P050B COLD START IGNITION TIMING PERFORMANCE - 2
P24B9 EVAP SYSTEM LEAK DETECTION PUMP PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE - 2
P24D6 EVAP SYSTEM PRESSURE SENSOR/SWITCH "B" CIRCUIT RANGE/PERFORMANCE - 2
  1. With the ignition switch ON (engine stopped), read the values in [Engine Coolant Temperature] and [Intake Air Temperature].
    NOTE:
    • SUBARU SELECT MONITOR. 

      For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .

    • General scan tool. 

      For detailed operation procedures, refer to the general scan tool operation manual. 

  2. If the values from step 1) satisfy the following conditions, idle the engine for two minutes or more.

    Condition: 

    |Engine coolant temperature - Intake air temperature|≤ 5°C (9°F)

    NOTE:
    • If the conditions are not satisfied, turn the ignition switch to OFF and wait until the parameters are satisfied. 
    • Hold the select lever in "P" range or "N" range at idling. 
  3. Read the temporary code using the Subaru Select Monitor or general scan tool. Ref. to COMMON (DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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