Please help, strange problems.

[Richiew1986]

Hi, I bought an Astra J a couple of weeks ago, since then a few problems have surfaced. It started after I removed the battery to replace the air bag and steering wheel. Code 16 came on, found that a bulb had blown so replaced that, code gone but still no brake lights. I then noticed that the brake lights would illuminate with the reverse light.

Today while driving I noticed that the brake lights are coming on but not when I press the pedal, seems to be in response to slowing down, then coming of when accelerating. maybe unrelated but my remote locking keyfob stopped working too.  I've never came across this problem before and think it's really strange, hope someone can help me shine some light on it. Really would appreciate some expertise on this, I'm going my wits end with it.

Looked on Opcom and there does seem to be some trouble codes. 

U0140-71 Lost communication with Body Control Module - Invalid data

C0277-06 Brake Pedal Position sensor circuit- Low voltage/open

C0277-4B Brake Pedal Position sensor circuit- Calibration not learned

C0890-003 Control module voltage reference output 3 circuit - undervoltage

[Jerry]

Looks like the faulty brake pedal sensor.

[Richiew1986]

Looks like the faulty brake pedal sensor.

[Richiew1986]

I've replaced the brake pedal sensor today with a brand new one, no difference.

[Jpbroad1970]

Bcm issues happen where they get a bit of moisture inside. Worth taking it out to have a look inside. Just remember to disconnect battery first. Bcm can throw up all sorts of faults.

[Jerry]

If you will check the BCM like Jpbroad1970 suggested, maybe a simple reset (battery disconnection) would help?

Maybe is just a poor grounding. If you have a multi-meter you can check for yourself. One contact on the bulb holder has almost no resistance to the chassis. The second should have the battery voltage (~ 12V) when the brake pedal is pressed. 

What about the third brake light (it's a LED type) does it works? Sometimes they are connected to the BCM but I'm not sure how it is on J. It would be worth checking this out as well.

[Richiew1986]

If you will check the BCM like Jpbroad1970 suggested, maybe a simple reset (battery disconnection) would help?

Maybe is just a poor grounding. If you have a multi-meter you can check for yourself. One contact on the bulb holder has almost no resistance to the chassis. The second should have the battery voltage (~ 12V) when the brake pedal is pressed. 

What about the third brake light (it's a LED type) does it works? Sometimes they are connected to the BCM but I'm not sure how it is on J. It would be worth checking this out as well.

The third brake light doesn't work in the usual way of pressing the brake pedal, but it does come on with the others when the car is in reverse.

[Jerry]

If you will check the BCM like Jpbroad1970 suggested, maybe a simple reset (battery disconnection) would help?

Maybe is just a poor grounding. If you have a multi-meter you can check for yourself. One contact on the bulb holder has almost no resistance to the chassis. The second should have the battery voltage (~ 12V) when the brake pedal is pressed. 

What about the third brake light (it's a LED type) does it works? Sometimes they are connected to the BCM but I'm not sure how it is on J. It would be worth checking this out as well.

The third brake light doesn't work in the usual way of pressing the brake pedal, but it does come on with the others when the car is in reverse.

Interesting, the stop lights only work when you put in reverse?
This makes me think that there may be a problem with a short circuit on the wires maybe.
I would remove one stop lamp bulb and use a multi-meter to measure the voltage (between ground and possitive contact):
1. When you press the brake pedal. -> you shoud read ~ 12V
2. When you put in reverse. -> no voltage 0V
3. When you have in reverse and press the brake pedal. -> you shoud read ~ 12V

---

Did you already checked the wires in the rubber hose coming out of the tailgate?
Maybe there the wires are damaged.

[Richiew1986]

Just to add closure to the thread, it was the BCM that was the problem. everything is back to normal with a new one in.