Help needed, U code (time to ditch the hoe?)

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

BlackDogBrian

TYF Newbie
Joined
Aug 1, 2017
Posts
29
Reaction score
4
Good Morning folks, looking for your help.

In short - need to decide if it is time to cut bait and get rid of my tahoe?

I purchased this PPV this summer. When I did, there was an error light on the dash. I assumed <insertassumptioncommentshere> that this might be a simple cracked wire at the hubs.
No error codes on my handheld scanned.

Today, have it in at the mechanics. They tell me getting a number of unrealted codes (U codes - body control issue). Long and short of it, they aren't getting an easy place to start.

He doesn't feel that there is anything mechanically wrong, if I was willing/able to live with the lights on the dash. The only thing I don't like - the traction control and the ABS don't work.
In the land of the ice and snow, I feel like these are manditory...

Has anyone else had any similar issues with a former Police vehicle?

Thanks in advance for your thoughts.
b.
 

Ron C

Full Access Member
Joined
Nov 4, 2017
Posts
727
Reaction score
173
Location
Los Alamos, NM
Good Morning folks, looking for your help.

In short - need to decide if it is time to cut bait and get rid of my tahoe?

I purchased this PPV this summer. When I did, there was an error light on the dash. I assumed <insertassumptioncommentshere> that this might be a simple cracked wire at the hubs.
No error codes on my handheld scanned.

Today, have it in at the mechanics. They tell me getting a number of unrealted codes (U codes - body control issue). Long and short of it, they aren't getting an easy place to start.

He doesn't feel that there is anything mechanically wrong, if I was willing/able to live with the lights on the dash. The only thing I don't like - the traction control and the ABS don't work.
In the land of the ice and snow, I feel like these are manditory...

Has anyone else had any similar issues with a former Police vehicle?

Thanks in advance for your thoughts.
b.


I thought that 'U' error/malfunction codes are error-codes where the pcm gets contradicting information, or data, that is inconsistent. For example a TPS that reports a setting that is not possible, or a shitf module that reports the stick is in park AND in neutral... stuff like that. However those codes are always proceeded with a general error, before the actual error is sent. (and these are always very vague...)

You can use a hand held reader, and look up error codes online. I believe errors you always get to see with these things, but other stuff like "stats etc" you would need a very specific one (or those expensive dealer ones). Also, you can clear errors, and watch for them coming up again. Some old errors might keep triggering the "check engine' light
 

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,821
Reaction score
44,945
Location
Li'l Weezyana
I have no personal experience with the PPV/SSV, but aren't some of the factory wires cut or at least tapped when some departments install some of their equipment? Maybe when that equipment was removed, circuits were left open or exposed. Don't their radar an/or dash camera equipment tap into the speed sensor? I'd guess that a failure on the speed sensor circuit could cause the traction control and ABS systems to be disabled. I'd first verify that there isn't anything that was messed with shorting out or just open circuits. Of course, use whatever code(s) you can get to help direct you to the problem.
 

techbiker

Full Access Member
Joined
Nov 12, 2017
Posts
114
Reaction score
86
There are traction control/ABS wires that run down both frame rails to the rear of the Tahoe. These unplug easily, especially if they get bumped when changing the rear shocks. When that happens, you get multiple warnings on the gauge cluster including an ABS and Traction Control warning.

Sounds like you just need a better mechanic or some time and a jack to check for loose/unplugged wires. Plugs contacts can also corrode. Drop the code reader and instead check all of your wiring.
 

CobraKing

Full Access Member
Joined
May 29, 2017
Posts
160
Reaction score
79
@BlackDogBrian Take a look under the dash and under the driver and passenger seats for any wires that have been cut. Then also look at the cargo area in the rear. The hackers who take off the police equipment literally just cut the harnesses and plugs. Try to look for any wires that may be touching each other.

Also as @techbiker said you need to inspect the plugs and harnesses under the car, it's possible one of them may have been damaged at some point.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,619
Reaction score
26,349
Location
Treasure Coast, Florida
You cannot properly diagnose these problems with those generic scanners, you need a TECH2. Where do you live? Maybe someone here, or maybe you know someone who has one? They are not expensive anymore. Post the exact codes and we'll see if we can help from this end.
 
OP
OP
BlackDogBrian

BlackDogBrian

TYF Newbie
Joined
Aug 1, 2017
Posts
29
Reaction score
4
thanks for the initial responses folks.

I've been told there are a whole bunch of errors conflicting, not sure where to start (and would be very pricey to fix everything potential...)
I will try a few of the items you've suggested, but I think it might be too much.

One big thing.... my truck came with a second battery. I assume this is what alot of the police lights etc were run off. it is still connected to the power, but the negative wire was cut off two inches from the negative battery terminal.... How would I rehook this up, is it a matter of grounding that negative post? or do I run this negative post to the negative post on the main battery? or just don't bother?
 

Ron C

Full Access Member
Joined
Nov 4, 2017
Posts
727
Reaction score
173
Location
Los Alamos, NM
thanks for the initial responses folks.

I've been told there are a whole bunch of errors conflicting, not sure where to start (and would be very pricey to fix everything potential...)
I will try a few of the items you've suggested, but I think it might be too much.

One big thing.... my truck came with a second battery. I assume this is what alot of the police lights etc were run off. it is still connected to the power, but the negative wire was cut off two inches from the negative battery terminal.... How would I rehook this up, is it a matter of grounding that negative post? or do I run this negative post to the negative post on the main battery? or just don't bother?


I have a setup like that in my 79 Jeep CJ5, There is/should be a battery separator (probably), they are fairly inexpensive from what I remember. Both batteries get charged at the same time, but they are separated from different circuits. In my situation, I have a red top for the vehicle and all it's stuff, and have a yellow deep cycle one that runs the winch. I can pretty much discharge the yellow top and nothing happens to the red top. Basically anything "extra" would run of the extra battery. I bought the separator from autozone or napa or so, and it comes with instructions on how to set it up. (man thing is that the negative poles need to be directly connected if not mistaken, but the instruction say how to do it. The separator has some poles to connect the alternator too and the batteries.
 

Ron C

Full Access Member
Joined
Nov 4, 2017
Posts
727
Reaction score
173
Location
Los Alamos, NM
Good Morning folks, looking for your help.

In short - need to decide if it is time to cut bait and get rid of my tahoe?

I purchased this PPV this summer. When I did, there was an error light on the dash. I assumed <insertassumptioncommentshere> that this might be a simple cracked wire at the hubs.
No error codes on my handheld scanned.

Today, have it in at the mechanics. They tell me getting a number of unrealted codes (U codes - body control issue). Long and short of it, they aren't getting an easy place to start.

He doesn't feel that there is anything mechanically wrong, if I was willing/able to live with the lights on the dash. The only thing I don't like - the traction control and the ABS don't work.
In the land of the ice and snow, I feel like these are manditory...

Has anyone else had any similar issues with a former Police vehicle?

Thanks in advance for your thoughts.
b.


On the error codes: I had a vehicle with some codes that I frowned upon. I used a reader and cleared the errors, waited until the light came on, and went through it. I noticed the order of the codes can be a little weird/off because the error requests of a sensor can be ignored, or erased, or added later when the PCM feels like it. I erased them, and checked what happened, but than again, I didn't have too many errors.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,260
Reaction score
39,384
Location
Stockton, Ca.
thanks for the initial responses folks.

I've been told there are a whole bunch of errors conflicting, not sure where to start (and would be very pricey to fix everything potential...)
I will try a few of the items you've suggested, but I think it might be too much.

One big thing.... my truck came with a second battery. I assume this is what alot of the police lights etc were run off. it is still connected to the power, but the negative wire was cut off two inches from the negative battery terminal.... How would I rehook this up, is it a matter of grounding that negative post? or do I run this negative post to the negative post on the main battery? or just don't bother?
Just go by any audio shop and have them make you up a new ground wire from any loose pieces they have around (they all do) it wont cost much, that wont resolve any of your code issue's but you will at least have both battery's hooked back up, you can just run it to the alternator bracket or just to the frame like mine is in this picture

batt.jpg
 

Forum statistics

Threads
132,381
Posts
1,867,160
Members
97,029
Latest member
mikefdny
Top