P1127 - Exhaust Not Warm Enough, Downstream Sensor Not Tested
WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
P1127 - EXHAUST NOT WARM ENOUGH, DOWNSTREAM SENSOR NOT TESTED
| Description: | The heated oxygen sensor (HO2S) monitor uses an exhaust temperature model to determine when the HO2S heaters are cycled ON. The test fails when the inferred exhaust temperature is below a minimum calibrated value. | ||
| Possible Causes: |
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| Diagnostic Aids: | Monitor the HO2S Heater PIDs to determine their ON/OFF state. DTC P1127 is present if the exhaust is not hot. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| Dedicated NGV | - | GO to HA: Natural Gas Fuel Control STEP 49 | - |
| All Others | - | GO to H: Fuel Control STEP 68 | - |