11 replies to this topic

[thatTTguy]

Hey everyone

So my check engine lights been on for a week or two now because of a P0031 Oxygen (A/F) sensor heater control circuit low (Bank 1 Sensor 1) code. I've tried cleaning it, reset the ecu and cleared fault codes, but the light comes back on straight away. The wires and plugs have been checked and look fine, so basically it looks like a new oxygen sensor is in order.

Before I fork out the stupid amount for a new one is there anything else I should be trying/looking for? Is there any fuses maybe?


Thanks
Adam

[Morgan]

My little guide here says that a faulty earth may cause this code?

[mark300]

if you've tried all that without any success sounds to me like its time for a new one.

[Sam]

This is what came up for me a few weeks ago. Was a dead O2 sensor. Replaced and good as new! Except the engine died a few days later... :/

[thatTTguy]

My little guide here says that a faulty earth may cause this code?

Haha awesome guide app thing! Yeah I might have another look tonight, trace the wires back a bit further but im doubtful

This is what came up for me a few weeks ago. Was a dead O2 sensor. Replaced and good as new! Except the engine died a few days later... :/

Awww no! that sucks dude.
just wondering did you buy the sensor from a dealer or online?

Edited by thatTTguy, 20 September 2012 - 04:27 PM.

[Sam]

Bursons. But that wasn't what made it go boom... Haha

[alexGT]

you can't clean oxygen sensors, just replace with new one.

[RX25SE]

This is not a fault with the sensor. It should produce a fluctuating DC voltage between 0.1v (lean) to 0.9v (rich) down one of the wires. The ECU also applies approx 400-450mV bias voltage to check there is something hanging off the end of the wire.

The fault here sounds as if the heating circuit (works like a 12v cigarette lighter) is drawing too little current due to high resistance. As Ty suggested, this may be a faulty earth.
You could check the coil resistance (two wires should be the same colour) too see if the heater has open circuit. You will need to look up the coil resistance specs.

The heater is used to bring the o2 sensor 'online' faster a the only start to produce a voltage at around 300degC.

[Morgan]

As Ty suggested

Morgan*

[RX25SE]

Morgan*

Sorry Morgs!


Brain fade seems to be working fine ATM!

[Morgan]

S'all gewd. Could be mistaken for worse people

Hai Ty

[thatTTguy]

Awesome! well not really awesome lol :/ ...but thanks for the help!