P0139

Tests 1 - 5:

Test 6:

SYMPTOM
P0139 - 1/2 O2 SENSOR SLOW RESPONSE

TEST NOTE
This symptom is diagnosed using the test P0133 - 1/1 O2 SENSOR SLOW RESPONSE.

WHEN MONITORED
Start engine. Allow engine to idle. For 1st part of test, if limits are exceeded, test passes. If not, 2nd part of test runs. amb/batt temp >44 °F, Baro >22.13" H20, battery >10.5 volts, MAP >11.79 & <18.15" H20, RPM >1350 & <2200 and vss >50 and <65.

SET CONDITION
The oxygen sensor signal voltage is switching from below 0.39 volts to above 0.58 volts and back fewer times than required.

POSSIBLE CAUSES
- Intermittent condition
- Exhaust leak
- O2 sensor signal circuit voltage drop
- O2 sensor ground circuit voltage drop
- O2 sensor