DTC P1646: Linear O2 Sensor Control Chip (Bank 1)
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 | ||