Starting Disabled, Service Throttle/Service Stabiltrak/Service Battery Charging System [2013 Savanna]

[Vantastic]

2013 GMC Savanna 1500 AWD

125,000 miles

 

Last year:

Last year my van broke down and wouldn't start, throwing a "Starting Disabled, Service Throttle" error on the dash. When I removed the negative battery from the cable from the battery and reconnected it I was able to start it and get to a autoparts store. I installed a new TPS (throttle position) sensor and haven't had any issues sense until recently. Shortly after I replaced the battery

 

Last week:

Van died in a customers driveway with the error code "Starting Disabled, Service Throttle/Service Stabiltrak". It also threw a check engine code, "P0601 Generic: Internal control module. Memory check sum error." I waited two minutes, van fires right up and I drove it another week. I cleared the check engine light after noting which one it was to see if it would come back, it never did

 

Today: 

Van dies on the highway with ALL the error codes this time, "Starting Disabled, Service Throttle/Service Stabiltrak/Service Battery Charging System". The 'service battery charging system' is new I hadn't had that one before. No check engine light. The van would not start until I disconnected and reconnected the negative battery cable from the battery. I checked what I could based off research on Google:

 

• Checked battery, it is only 6 months old and is at 12.97 volts
• Checked voltage with the van running to check alternator: 14.8volts
• Checked battery terminals for corrosion(none)
• Battery cables firmly attached
• Belts to alternator seem to be in good condition and run smoothly
• Starter sounds good, fires engine up right away
• No strange engine noises or rumbling sounds
• Van's electrical system still work (lights, radio, dash)

 

I just started an HVAC company and this is my work van, its gonna be rough on the new business if I need to take it to a dealership. However I will if I must

Edited July 25, 2023 by Vantastic

[Jsdirt]

There is ZERO reason to take a ten year old vehicle to a dealership, unless you enjoy a 300% markup on a repair any competent private garage can do. They don't call 'em "stealerships" for nothing!

 

Now I have to say this before someone gets their feathers ruffled, even though I feel like a broken record ... THIS IS NOT BECAUSE OF THE TECHS WORKING THERE. It's because of GM corporate! They screw the techs as badly as their customers. If I never give another PENNY to GM again in my life, it'll be too much money! 

 

 

 

OK ...this screams of a bad connection somewhere. Since your an HVAC tech, troubleshooting isn't a foreign concept to you, and you'll be able to track this down with a wiring diagram. The shitty part about this is you have to pay for service info. That's the world automakers have created today. They've built vehicles so complicated that working without one has become just about impossible, unless you have endless hours to spend under a hood ... which owning your own business tells me, no F'in way is that true! 

 

If you want to fix this, and any other issues down the road, you'll need at a minimum a good scanner. The basic ones will only read codes only in the PCM, but if you spend more money you'll get bi-directional control (Makes troubleshooting by yourself 1,000% easier), multiple module code-clearing capability, and good live data. Would be good to be watching live data when the problem happens. If you suddenly lose communication with the PCM from the scan tool when the issue happens, then you can focus on checking powers and grounds to the PCM.

 

Best thing you can do right off the bat, just to rule out any issues is do a THOROUGH visual inspection of ALL wiring. Focus on areas of heat and vibration. ANY areas where the harness contacts metal, no matter how protected they look, are suspect. Wiring today is made by the lowest bidder. You've got over 1,000 miles of it in that truck, and just ONE wire can cause this. Sometimes just a good visual will reveal an issue. Takes LOTS of patience, however.

 

Next course of action if a visual turns up nothing, is to remove ANY ground you see - including the battery ground (And positive just to be sure) - sand / wire wheel / brush where it contacts & the bolt, and reinstall. I mean ANY ground wire you see - behind the engine, driver's side of engine by P/S pump, under the truck - do 'em all. Give them a tug and make sure they're intact.

 

Check the fuse box under the hood. If you see anything green, that's bad. That's corrosion of copper. Green in any connectors or wiring is bad as well. We see it a lot up here in the salt belt of MA.

 

Something you'll probably never see as an HVAC tech is wiring so shitty that it can and will break INSIDE INTACT JACKETING! I've seen it 100 times! If a wiggle test reveals a problem area, tugging on that wire with a hand on each side of the suspected issue (Like you're trying to pull it apart) can sometimes stretch the jacketing - a dead ringer for broken copper strands inside. I wouldn't have believed it if I hadn't seen it for the first time over 7 years ago on something much older than yours.

 

If all that fails, go to https://www.alldata.com/diy-us/en/diy-repair-information  and grab a diagram. Will be the best money you ever spend. Keeping your symptoms in mind & focusing on those systems that could cause this particular issue should get you zoned into the right wiring.

 

The last option is if you don't want to be bothered with any of this, just research local NON DEALER shops in your area with good reviews. Check all the different places for reviews - Google Maps, Yellow Pages, etc.. Go with the best one - particularly a shop that does a lot of electrical & driveability troubleshooting, and just wash your hands of it all.

[Vantastic]

Thank you Jsdirt for taking the time to write up that thoughtful response. I have been working on going through all of your suggestions but would like to update that I was able to use a friend's scanner the next time it died on me and I am seeing these error codes under the ECM Data Stream:

 

• Reduced Engine Power History: Throttle Actuator Control (TAC) DTC
• PO601-00:
  • Control Module Read Only Memory (ROM)
  • Last Test: Failed/Current
  • This Ignition: Passed & Failed
  • Since Clear: Passed & Failed

I have been checking for bad connections somewhere as you suggested and haven't found anything yet. Also cleaned up grounds, looked for problem areas around metal/heat sources, ect.

 

I will keep searching and probably grab a diagram from alldata.com as recommended. 

 

Thank you again for your assistance

[Jsdirt]

I would focus your attention around the throttle body, and especially the wiring to the actuator. Those have been problem areas on past GM trucks. Can't recall for certain, but I believe there was a TSB out on that particular issue - any time the throttle body was replaced it was required to replace the pigtail as well.