DTC P1646: Linear O2 Sensor Control Chip (Bank 1)
WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, 2011 Ford Fusion, 2010 Mercury Milan, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
P1646 - LINEAR O2 SENSOR CONTROL CHIP (BANK 1)
| Description: | The powertrain control module (PCM) monitors the application-specific integrated circuit that controls and monitors the universal heated oxygen sensor (HO2S). The test fails when the PCM detects an internal circuit or communication concern. | ||
| Possible Causes: |
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| Diagnostic Aids: | Internal PCM concern. Reprogram or update the calibration. Check for other DTCs and diagnose those first. Make sure to check for aftermarket performance products before installing a new PCM. Clear the DTCs, repeat the self-test. If the DTC is retrieved again, install a new PCM. Refer to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , PROGRAMMING THE VID BLOCK FOR A REPLACEMENT PCM . | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | Refer to the Description, Possible Causes and Diagnostic Aids for the DTC in table | ||