Daily Dash Light Flash

Since the cold sub zero temps have set in it seems that the flashing dash lights come on each time I start the truck. Any thoughts as to why the cold is exacerbating this issue?

 

Temperature can affect electronics because things expand and contract with temperature change.

I'm still suspect of those grounds, they look pretty crusty.
Could always check voltage drop from the negative terminal of the battery to each ground wire (not the ring terminal or bolt) when it's acting up to verify them.

Also a full system code scan of the truck may be helpful.

 

Thanks. Im waiting for some warmer weather to clean the grounds. Would it be helpful to run a temporary ground from the negative on the battery to the ground points to quickly troubleshoot where the bad ground might be?

 

You could go to the body and frame just to rule out main grounds but the individual ones would be pretty hard to do that on

 

I pulled the battery and cleaned a few of the grounds under the hood. After putting everything back together now I have a P0333 code for the knock sensor. I only cleaned these…

any suggestions?

 

Any updates ?? Very curious to see the resolution to this...

 

I will add an update. For now I am waiting for the right weather and some time.

 

Here is an update.

I cleaned and reassembled the four body grounds under the hood. I tested these four grounds as well as two grounds that sit on the back of the engine.

I also checked the frame ground at the drivers side front wheel

I still have the flashing dash lights when I start it as well as the addition of a Knock Sensor error now.

Any other suggestions??

Thanks

 

Could my cleaning the grounds have caused the Knock Sensor issue? It literally started after I cleaned the grounds and started the truck up. It seems related to the grounds and not to a critter eating wires or a bad sensor. With the CEL on the trucks seems to rev higher and use more gas on highway trips. Seems figuring out the Knock Sensor issue has become my new priority. Does anyone have a recommendation on next steps to take?? Thanks

 

I wouldn't think cleaning the grounds has anything to do with the knock sensor codes, more likely chewed or corroded wires.
Can you get a mirror and look around behind the intake manifold where the knock sensors wires come up?

 

I cannot see the wires well with a mirror but I can see some acorns and debris. So I suspect i have a chewed wire.

 

Its been some time since my last post. I replaced the knock sensor harness. It was chewed clean off. I still have the flashing lights on the dash for 5 minutes or so after I start it for the first time each day. Grounds look good to me. Could this be a computer issue? One thing that I noted the other day is if I start it and immediately put it in reverse the back up camera works. As I mentioned before when the dash lights are flashing the camera doesnt work but it seems that if I get it into gear quick the camera will work. Im not sure if that is a helpful diagnostic piece. I appreciate any suggestions!

 

ALTERNATOR…

As the last few months have passed, the daily flashing lights have been occurring every time I start the truck. Last week it began starting hard and when I tested the battery I could see an overcharge from the alternator. Incidentally I had tested the charging system and the grounds when all of this all started last year and it seemed within correct limits.

I bought a new battery and the overcharge continued so I disconnected the alternator b post, started the truck and had no flashing dash lights. I swapped out the alternator and now no dash warning lights. So it would seem that an overcharge from the alternator was the culprit. Thanks all for your suggestions. I hope the helps someone else. If you have odd warning lights flashing at start up for 5 minutes or so try disconnecting the b post of your alternator to see if that is the problem.

 

Very interesting and crazy but at least it's fixed, pretty rare to see an alternator overcharge.

 

Agreed. It was an odd problem.

 

im having similar issues today. But its when I hit a dip or small bump in the road. Hoping its a ground, and not alternator. But its definitely been a couple years since Ive done an alternator

 

For me it was a constant flashing light after starting up, it was not intermittent. Sounds like you have a ground issue. But you could always test the alternator to rule it out.

 

I will check. I need to figure out where the grounds are