Hey folks,
I drive a 2012 Mazda 3 hatchback (2.0L automatic) and recently ran into an issue I could use some help with.
While driving on the highway, the car jerked hard, and the AT light came on. The check engine light has been on for a while now. I scanned it and only got one permanent code:
P0138 – O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)
(This is the downstream oxygen sensor, after the catalytic converter.)
What’s strange is that the scanner didn’t detect any transmission-related codes, even though the AT light came on and I’m now feeling rougher shifts.
Also, just to note — I had the transmission fluid changed about 8 months ago during routine maintenance.
Questions:
Could a faulty downstream O2 sensor cause the AT light or impact shifting?
Is this maybe a wiring/grounding issue affecting both the O2 sensor and TCM?
Anyone had a similar issue with no trans codes but shifting problems?
Is it safe to continue driving like this temporarily?
Thanks in advance
I drive a 2012 Mazda 3 hatchback (2.0L automatic) and recently ran into an issue I could use some help with.
While driving on the highway, the car jerked hard, and the AT light came on. The check engine light has been on for a while now. I scanned it and only got one permanent code:
P0138 – O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)(This is the downstream oxygen sensor, after the catalytic converter.)
What’s strange is that the scanner didn’t detect any transmission-related codes, even though the AT light came on and I’m now feeling rougher shifts.
Also, just to note — I had the transmission fluid changed about 8 months ago during routine maintenance.
Questions:
Could a faulty downstream O2 sensor cause the AT light or impact shifting?
Is this maybe a wiring/grounding issue affecting both the O2 sensor and TCM?
Anyone had a similar issue with no trans codes but shifting problems?
Is it safe to continue driving like this temporarily?
Thanks in advance
