Frank R

Hello, I am a new Tahoe owner and was hoping someone could help me diagnose an issue. I recently bought an ’03 Tahoe LT with the 5.3 engine, 137k miles. I bought the vehicle primarily for towing my camper and up until now have been generally happy with it. About a month ago, the SES light came on and it threw a code for the MAF sensor. I took it out and cleaned it and the SES never came back.

I’ve also had intermittent symptoms of a weak battery – when you turn the key nothing will happen for maybe 3-5 seconds no clicks, nothing, then it will turn over very slowly and then start. Like I said it’s intermittent – sometimes it will sit for a week and fire right up and other times if I shut it off for 2 minutes to get gas it will be hard to start. No rhyme or reason to it, but everytime it is hard starting I’ve noticed that the clock resets to 12:00. I’ve also got intermittent ABS light/symptoms and the doors will occasionally lock and unlock very quickly for no reason. I have no idea if these issues have a common cause or not.

Yesterday, when leaving the campground towing my trailer it started right up, no problem. I shut it off to empty the trailer tanks (5 minutes) and it was very hard to start and twice it started and died immediately. The third time it stayed running and I pulled out. I immediately noticed it had absolutely no power, the engine would not rev over 1k RPM. I also noticed that the odometer/message center and gear indicator were not lit up in the instrument cluster. I pulled over, shut it off and re-started. It started easily and the odometer and gear indicator were back. However, the Message center read “Low Engine Power” and again the motor would not rev. I shut it off and restarted a few times but it made no difference. I then pulled the MAF – it looked fine and I reinstalled. Tried it again – it fired right up and ran fine all the way home. I have a SES light on now, but have not been able to have the code pulled yet as I was afraid to shut it off on my way home.

My apologies for the lengthy post, but I wanted to give all the info I could. I would greatly appreciate any input you can offer on troubleshooting this issue. I have a couple camping trips coming up soon and I just don’t trust this for towing at the moment. Thank you! <input value="2" type="hidden">
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in2pro

Welcome to the forum....

I would have the battery and charging system checked (load tested)
I would also strongly suggest cleaning up the battery cables at all ends, check for any any corrosion and replace cables that show any signs of corrosion.

Check the ground cable and the ground strap from the engine block to the chassis/body

The hard starting could be fuel pump related, I would suggest checking the fuel pressure just to eliminate the fuel pump as an issue of the hard start.

I am betting most of the issues you are seeing are a weak battery and poor electrical connections, most likely a ground cable/connection.


Please do get that error code read and let us know what you find and we can go from there



.

Frank R

Thank you for your input thus far.

Ok, I took the Tahoe to work this morning so I could get the code(s) pulled and have the battery and alternator checked. It started right up (was parked for about 2.5 days) and the clock was not reset. The SES light did not come on. It ran fine for the entire trip and started fine each time I shut it off. The only issue was the intermittent ABS light. I took it to Advance Auto – there were no codes showing. I had them check the battery and alternator and the results were as follows:

Battery:
CHARGE REQUIRED
Voltage: 12.5
Measured: 463CCA
Rated: 650CCA
Temp: 104

Charging System:
No Load: 14.03V, 2.1 A
Loaded: 13.88V, 3.5A

Drain Test: 0.09A

The cables at the battery look clean and in good condition. I still need to check the other ends when I can get dirty. Same with the ground strap – what I can see of it looks good, but I need to inspect further. Any additional thoughts?

in2pro

Those battery readings should tell you something, how long was your drive in? if it was a really short drive then the "Charge Required" might marginally be acceptable but if your trip was at highway speeds for more the 15-20 min, in my opinion should have been enough to show charged...
I personally would replace the battery if it was more then 3-4 yrs old its an easy fix and there is really nothing to be gained from wrenching every last volt of usefulness out of it... granted I could be jaded due to the fact my 07 goes through batteries at about that rate... I am on number 4...

What's the first thing you do when the TV Cable remote starts acting up...?

Frank R

I push the buttons harder

The drive from home to where it was tested was approx 7 miles, split evenly between highway speeds and in-town, stop and go driving.