Codes P0700 and U0073

Tiny
CHRISTA DICKSON
  • MEMBER
  • 2008 CADILLAC ESCALADE
  • 140,000 MILES
Vehicle pulling p0700 and u0073, warning lights illuminating, trac control stops working and RPM's wig out bad. It acts like it wants to shut off. Also not sure what this wire is, I included a pic. But it looks like it broke. Not sure what it is or if it's supposed to be connected.
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Saturday, November 21st, 2020 AT 4:06 PM

12 Replies

Tiny
CHRISTA DICKSON
  • MEMBER
Sorry for some reason it wont let me upload, but the wire in talking about is a small wire coming off of the bolt on the side on the 175 fuse located on firewire.
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Saturday, November 21st, 2020 AT 4:18 PM
Tiny
ASEMASTER6371
  • EXPERT
Good evening,

The 700 is a general code for the transmission indicating there are other codes. The 73 is a communication issue.

https://www.2carpros.com/articles/automatic-transmission-problems

Can you communicate with the transmission control module. The most common issue is dirty connections at the connectors for the module. I posted the location of the module for you below.

Roy

GM has several TSB with similar symptoms.

08-07-30-021H: Loss of High Speed GMLAN Communications, Intermittent No Crank, IP Gauge Fluctuation, Intermittent Door Lock Cycling / Chime Operation, Various IP Warning Lamps Illuminated, Transmission May Not Shift, Communication DTCs U0073, U0100, U0101, U0102, U0109, U0121 or U0140 Set - (Jun 25, 2015) in ALLDATA

1. PIT4667D: Diagnostic Tips - Diagnosing High Speed LAN Concerns - (Jul 13, 2015) in ALLDATA Community

2. TSB 08-07-30-021H: Loss of High Speed GMLAN Communications, Intermittent No Crank, IP Gauge Fluctuation, Intermittent Door Lock Cycling / Chime Operation, Various IP Warning Lamps Illuminated, Transmission May Not Shift, Communication DTCs U0073, U0100, U0101, U0102, U0109, U0121 or U0140 Set - (Jun 25, 2015) in ALLDATA

4. PIT4730A: Additional Diagnostic Information For U0140 Or U0073 - keywords comm DIC gage gauge inop inoperative int lan message speedo start tach - (Jun 18, 2010) Library request

5. PIT3993C: No Crank / No Start At Times - keywords code communication DTC high lan speed U0100 U0101 U0102 U0140 U2100 U0073 - (Nov 7, 2007) in ALLDATA Community

73

DTC U0073 or U2100

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Vehicle > Initial Inspection and Diagnostic Overview
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC U0073 00
Control Module Communication Bus Off

DTC U0073 71
ECU HS Bus Off

DTC U0073 72
ECU LS Bus Off

DTC U2100 00
Controller Area Network (CAN) Bus Communication

DTC U2100 47
Controller Area Network (CAN) Bus Communication

Circuit/System Description

The serial data circuits are serial data buses are used to communicate information between the control modules. The serial data circuits also connect directly to the data link connector (DLC).

Conditions for Running the DTCs

Supply voltage at the modules are in the normal operating range.
The vehicle power mode requires serial data communications.

Conditions for Setting the DTC

The module setting the DTC has attempted to establish communications on the serial data circuits more than 3 times.

Action Taken When the DTCs Sets

The module suspends all message transmission.
The module uses default values for all parameters received on the serial data circuits.
The module inhibits the setting of all other communication DTCs.

Conditions for Clearing the DTC

A current DTC clears when the malfunction is no longer present.
A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Circuit/System Verification

1. Refer to Data Link References to determine which serial data system is used for a specific module. See: Information Bus > Initial Inspection and Diagnostic Overview > Data Link References
2. This DTC cannot be retrieved with a current status. Diagnosis is accomplished using the symptom Scan Tool Does Not Communicate with High Speed GMLAN Device or Scan Tool Does Not Communicate with Low Speed GMLAN Device.
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Saturday, November 21st, 2020 AT 4:22 PM
Tiny
CHRISTA DICKSON
  • MEMBER
Okay, great. Thanks for your reply. I have got a couple things i'm going to check on it today before I resort to getting another TCM. I only have al very basic scanner al the moment. Only pulls basic engine codes so i'm not able to check any of that further. This is on my cousins car she just spent $10,000.00 cash on it 2/ months ago, so i'm just trying to help her figure it out. (I am currently in school for high performance modification certification). So i'm not clueless by any means but have a lot to learn as well. And i'm limited to this basic scanner currently.
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Tuesday, November 24th, 2020 AT 3:36 AM
Tiny
ASEMASTER6371
  • EXPERT
Let me know when you get an advanced scanner. Then you can monitor the solenoids and command them on and off.

Roy
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Tuesday, November 24th, 2020 AT 4:31 AM
Tiny
CHRISTA DICKSON
  • MEMBER
Is there a place I can rent one? Or do you think replacing the TCM will fix the problem? That was the route I was going to go for now.
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Tuesday, November 24th, 2020 AT 1:53 PM
Tiny
ASEMASTER6371
  • EXPERT
You would have to call around and see if they will rent one.

The TCM is an expensive guess since you need to buy a new one and have it flashed or programmed to your car.

I attached the location and procedure for you below.

Roy
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Tuesday, November 24th, 2020 AT 1:59 PM
Tiny
CHRISTA DICKSON
  • MEMBER
I'm on my way to Pick-N-Pull now. I'm going to try to get one from there since it'll be a lot cheaper. So that's where I'm headed. There's two different things I've read one is that it's up in the engine compartment and the other is that it's in the back in the transmission case which one is it? It's up in the front of the engine bay right correct? And I've gotten one from Pick-n-Pull before and the third one that I got actually fixed my problem on my Mazda it wouldn't even like move when I had to come to a dead stop trying to accelerate again was difficult and replacing the TCM fixed that issue. The third one that I got was a good one from Pick-n-Pull and so I didn't have that problem anymore. But with that one I really didn't have to reflash or program anything. I just put it in and then it learned itself. Again I thought that would be the same situation here from what I understood and I'm sorry if this is so long but I'm using talk to text while I'm driving. But if you could let me know I would greatly appreciate it, thanks.
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Tuesday, November 24th, 2020 AT 2:10 PM
Tiny
CHRISTA DICKSON
  • MEMBER
Okay, update: I had left my tools on my Mustang and was in Avalon so i'm not going to make it to the yard today. They stop letting people in 4:30, so ill halve to go tomorrow. I'm just asking if you were me didn't have a more advanced scanner and were looking for the cheapest way to get cousin's Escalade running normal. Which route would you go or what do you suggest I do from here?
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Tuesday, November 24th, 2020 AT 2:20 PM
Tiny
ASEMASTER6371
  • EXPERT
You are taking a chance with a junkyard unit. It still has to be programmed to you VIN number for it to function.

It is where the picture I sent you. It is under the battery in the engine compartment.

I would have someone with a scan tool check and see if the TCM is working first.

Roy
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Tuesday, November 24th, 2020 AT 2:22 PM
Tiny
CHRISTA DICKSON
  • MEMBER
Okay, I just drove it myself and got a little better of a idea of what exactly it's doing. I don't know l if it will make a difference or if you will be able to give me an idea without better scanner because I don't halve access to one or money for one at the exact moment. But the stabitrac off comes up then and only then the RPM's will repeatedly drop then come back up pretty fast.T feels likes its stuck in a lower gear when this happens. Also I was able to include al pic of the wire that i'm not sure what or if it should be connected or grounded or what? If you know. Thanks
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Wednesday, November 25th, 2020 AT 9:06 AM
Tiny
CHRISTA DICKSON
  • MEMBER
Also a humming sound coming from sound like drivers floor board if sitting with key in on position.
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Wednesday, November 25th, 2020 AT 9:14 AM
Tiny
ASEMASTER6371
  • EXPERT
Somebody added that wire to that stud. That is not factory at all.

As far as the stability control, that is an ABS issue.

https://www.2carpros.com/articles/abs-warning-light-on-easy-repair-guide

https://www.2carpros.com/articles/automatic-transmission-problems

If I were you, take it to a parts store and have them read the codes for you. It is a free service.

Then let me know what other codes come up.

Roy
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Wednesday, November 25th, 2020 AT 9:18 AM

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