NHTSA ID Number: 10114600
Manufacturer Communication Number: PIT4667D
Summary
This Preliminary Information communication advises the technician of additional steps for diagnosing General Motors
high speed local area network. This should only be used if normal service information doesn’t lead to a diagnosis this is not a replacement for normal service information.
107 Affected Products
Vehicles
| CADILLAC | ESCALADE | 2007-2014 |
| CADILLAC | ESCALADE ESV | 2007-2014 |
| CADILLAC | ESCALADE EXT | 2007-2013 |
| CHEVROLET | AVALANCHE | 2007-2013 |
| CHEVROLET | SILVERADO 1500 | 2007-2011 |
| CHEVROLET | SILVERADO 2500 | 2007-2014 |
| CHEVROLET | SILVERADO 3500 | 2013 |
| CHEVROLET | SUBURBAN | 2007-2014 |
| CHEVROLET | TAHOE | 2007-2014 |
| GMC | SIERRA 2500 | 2007-2014 |
| GMC | SIERRA DENALI | 2007-2013 |
| GMC | YUKON | 2007-2014 |
| GMC | YUKON DENALI | 2007-2013 |
| GMC | YUKON DENALI XL | 2007-2013 |
| GMC | YUKON XL | 2007-2014 |
| HUMMER | H2 | 2008-2009 |
SEOCONTENT-START
Bulletin No.: PIT4667D
Date: Jul-2015
Subject: Diagnostic Tips – Diagnosing High Speed LAN Concerns
Models: 2007-2014 Cadillac Escalade, ESV, EXT
2007-2013 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2014 Chevrolet Silverado HD, Suburban, Tahoe
2007-2013 GMC Sierra and Yukon Model
2014 GMC Sierra HD and Yukon Models
2008-2009 Hummer H2
This PI was superseded to update Model Year and Recommendation/Instructions. Please discard PIT4667C.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Note: As of the 2015 calendar year, the Data Bus Diagnostic Tool is available to assist in diagnosing issues with High Speed LAN. Refer to the Data Bus Diagnostic Tool User Guide, available in SI under Select and View a User Guide on the base screen. If after using the Data Bus Diagnostic Tool and the cause of the issue has not been found continue with the below information.
The data link connector (DLC) allows a scan tool to communicate with the high speed GMLAN serial data modules. The serial data is transmitted on 2 twisted wires that allow speed up to 500 Kb/s. The twisted pair is terminated with two 120-ohm resistors, one is internal to the engine control module (ECM) and the other at the opposite end of the high speed bus after the last module. If a communication signal is lost, the software application will set a no communication code (“U” code) against the respective control module. This code is mapped on the Tech 2 screen as a code against the physical device. Note: a loss of serial data DTC does not represent a failure of the module that the code is set in. If you experience a current or intermittent loss of communication with a high speed LAN module, the following diagnostic tips may help you locate the source of the concern.
Recommendation/Instructions
Note: This document is only to provide additional tips when diagnosing high speed LAN concerns and is not meant to replace SI or be a diagnostic flow chart as each tip is its own test. Always, perform and refer to SI for the latest diagnostic information and procedures.
1. If the Tech 2 cannot communicate with any high speed LAN modules check for proper terminal drag at the DLC terminals 6 & 14 using test probe J35616-14 or -2A. In many cases, DLC terminals 6 & 14 can become damaged from repeat probing and/or installing the scan tool.
2. Verify the high speed LAN circuit integrity by measuring the resistance across DLC terminals 6 & 14 with a DVOM and the battery(s) disconnected. A normal reading would be 60 ohms +/- 5 ohms. A reading something less than 60 ohms would indicate that high speed LAN bus is shorted together. If the reading is something higher than 60 ohms this indicates high resistance/open in the high speed LAN bus.
3. If the high speed LAN circuit integrity is good and the scan tool still will not communicate with any high speed LAN modules, there could be a module corrupting the high speed LAN bus. To try an isolate which module is causing the concern, try the following three different methods:
– Remove the battery feed fuse for each high speed LAN module one at a time, while monitoring the scan tool to see if communication returns with the other modules.
– Disconnect each module one at a time and bypass the module by using jumper wires to connect the high speed LAN bus back together. NOTE: Many high speed LAN modules use small .64 series terminals. ONLY use the connect test probe/terminal when bypassing the module. If the .64 series test probes/terminals are needed, please refer to the latest version of PIT5074 for the information – Another method to isolate the high speed LAN modules is to separate the bus into two halves by disconnecting the C3 (X3) connector from the back of the left I/P junction block. The following steps listed below will explain how to locate and disconnect the C3 (X3) connector. With the C3 (X3) connector removed, only the ECM, TCM, and BCM will be online with the scan tool. If you are able to communicate with these modules, the concern is on the side of the bus that is disconnected.
Note: This step will cause an open in the high speed LAN bus and if you measure the resistance across DLC terminals 6 & 14 it will be around 120 ohms. This is ok while performing this test.
Locate the left IP junction block, and remove the cover Squeeze the locator tabs and remove junction block from holding bracket.
Locate the Green C3(X3) connector that is located on the back of the junction block. Remove the C3(X3) connector from the bottom of the IP fuse block, this will isolate the high speed LAN modules in two halves.
INTERMITTENT HIGH SPEED LAN CONCERNS
For intermittent issues try the following test:
If the high speed LAN communication concern is intermittent or you get a vehicle that returns with multiple “U “codes, use the following test to try and isolate the area of concern.
– Disconnect the vehicles battery(s).
– Locate the DLC connector and probe terminals 6 & 14 using the proper test terminals contained in terminal test kit J-35616-14 or -2A.
– Using a DVOM, measure the resistance across terminals 6 & 14 at the DLC connector. The resistance should be around 60 ohms and remain steady.
– Have an assistant wiggle test the wiring at each high speed LAN module while monitoring the DVOM reading looking for any type of fluctuation. If the reading varies while wiggle testing the wiring, check for proper terminal drag/terminal to wire crimp/ and circuit integrity at the effected module and repair as needed.
Note: Many high speed LAN modules use small .64 series terminals and are the main culprit for intermittent electrical concerns. When probing modules or inline connectors with .64 series terminals be sure the correct 64 test probe is being used. There are three easy ways to obtain these .64 series test terminals and refer to the latest version of PIT5074 for the information.
ADDITIONAL SI KEYWORDS:
U1814 U2100 U2099 U0100 U0101 U0102 U0121 U0140 U2100 U0073 ABS brake crank indicators IPC lamp light start Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
SEOCONTENT-END
Bulletin No.: PIT4667D
Date: Jul-2015
To View or Download this Document Click Here
- CEL Doctor: The ANCEL AD310 is one of the best-selling OBD II scanners on the market and is recommended by Scotty Kilmer, a YouTuber and auto mechanic. It can easily determine the cause of the check engine light coming on. After repairing the vehicle's problems, it can quickly read and clear diagnostic trouble codes of emission system, read live data & hard memory data, view freeze frame, I/M monitor readiness and collect vehicle information
- Sturdy and Compact: Equipped with a 2.5 foot cable made of very thick, flexible insulation. It is important to have a sturdy scanner as it can easily fall to the ground when working in a car. The AD310 OBD2 scanner is a well-constructed mechanic tool with a sleek design. It weighs 12 ounces and measures 8.9 x 6.9 x 1.4 inches. Thanks to its compact design and light weight, transporting the device is not a problem. The buttons are clearly labelled and the screen is large and displays results clearly
- Accurate Fast and Easy to Use: The AD310 scanner can help you or your mechanic understand if your car is in good condition, provides exceptionally accurate and fast results, reads and clears engine trouble emission codes in seconds after you fixed the problem. This device will let you know immediately and fix the problem right away without any car knowledge. No need for batteries or a charger, get power directly from the OBDII Data Link Connector in your vehicle
- OBDII Protocols and Car Compatibility: Many cheap scan tools do not really support all OBD2 protocols. AD310 scanner as it can support all OBDII protocols such as KWP2000, J1850 VPW, ISO9141, J1850 PWM and CAN. This device also has extensive vehicle compatibility with 1996 US-based, 2000 EU-based and Asian cars, light trucks, SUVs, as well as newer OBD2 and CAN vehicles both domestic and foreign. Pls confirm with our customer service whether it is compatible with your vehicle before purchasing
- Home Necessity and Worthy to Own: This is an excellent code reader to travel or home with as it weighs less and it is compact in design. You can easily slide it in your backpack as you head to the garage, or put it on the dashboard, this will be a great fit for you. The AD310 is not only portable, but also accurate and fast in performance. Moreover, it covers various car brands and is suitable for people who just need a code reader to check their car
- MAINTAIN PEAK PERFORMANCE AND SAFETY ON THE ROAD - Easily find and fix the problem with your vehicle using the INNOVA 5610 bidirectional scan tool. This OBD2 scanner diagnostic tool provides real-time solutions to troubleshoot issues. Access OBD2 and OEM live data with ease, making it an essential car scanner diagnostic tool. Perfect for those seeking reliable car diagnostic scanner and code readers & scan tools for vehicles.
- PRO-LEVEL FUNCTIONALITIES - Use the INNOVA 5610’s Enhanced Data Stream to view live data for advanced systems like ABS, SRS, transmission, and engine. The Special Reset Function lets you use dealership-level re-learn procedures. This car diagnostic scanner is ideal for those needing a bidirectional scan tool or mechanic tools automotive for professional repairs. Compatible with select vehicle makes and models; not universal.
- COMMAND WITH BIDIRECTIONAL CONTROLS - The INNOVA 5610 bidirectional scan tool sends commands to test functions such as fuel pump on/off or retracting the electronic parking brake. With this car scanner diagnostic for all cars, you can operate like a pro. Ideal for those seeking a car code reader and reset tool or advanced fixd car diagnostic tool capabilities. Compatible with select vehicle makes and models; not universal.
- EASY TO USE - The INNOVA 5610 OBD2 scanner diagnostic tool supports English, Spanish, and French. Easily use this scanner for car on most 1996 - 2023 (2024 coming soon) OBD2 vehicles to verify repairs. Designed for ease of operation, it’s a dependable code reader for cars and trucks and check engine code reader. To confirm vehicle coverage, please utilize Innova's Coverage Checker.
- BUY AND DRIVE WITH CONFIDENCE - Backed by ASE-Certified support, this car scanner pairs with the RepairSolutions2 app, trusted by 4M users, for wireless OBD scanner functionality. With free updates and no subscription fees, this durable car computer diagnostic reader ensures you’re prepared for any repair. A must-have diagnostic scanner for vehicles.
- 2026 Advanced ECU Coding Scan Tool: Maximize the capabilities of your vehicles with the ArtiDiag Pro. This scan tool, seamlessly compatible with renowned models such as VW, A-U-D-I, SKODA, SEAT, BENZ, and more, empowers you to uncover hidden features, deactivate annoying functions, and code retrofitted components for peak performance. Ensure a backup before coding and steer clear of problems on low battery levels.
- Efficient Diagnostics with Bidirectional Control: Say goodbye to uncertainty, streamline diagnostics, and reclaim valuable time with ArtiDiag Pro scan tool. This bidirectional scan tool exceeds expectations, enabling targeted tests on individual actuators to swiftly identify and resolve issues. Covering lights, door locks, fuel and coolant systems, windows, wipers, EVAP, and more in vehicle components.
- 35+ Services Resolve 90% of Repair Challenges: Unleash maximum productivity with the ArtiDiag Pro, a scan tool that tackles 90% of maintenance issues through its 35 special functions. Effortlessly clear oil maintenance indicators with oil reset. Engage the EPB Reset for brake system management and establish precise alignment with the Steering Angle Reset to define the straight-line reference position for your vehicle.
- FCA Autoauth : This diagnostic tool supports Autoauth for FCA SGW/Renault, Chrysler, Jeep, Dodge, Fiat etc. 2017 and later. NOTE: Due to Product Upgrade, there is no Chrysler 12+8 adapter, the BMW-20 Adapter in the package any more. We are sincerely sorry for the inconvenience. NOTE: Please confirm compatibility before purchase.(Topdon Website>Support>Vehicle Coverage)
- Professional Customer Support: At TOPDON, your satisfaction is our unwavering commitment. Experience hassle-free support and a lifetime of expert assistance. Should you encounter any challenges, reach out to us at 833-629-4832. For returns, please damage the packaging to prevent Amazon from reselling it. Please be advised that after two years, a subscription fee of 249 Bucks will apply.
- [Diagnose Like a Pro] BlueDriver Pro is a professional OBD2 scanner and diagnostic tool that helps you scan, understand, and clear vehicle trouble codes with confidence. Turn your phone into a powerful car diagnostic scanner—no guesswork, no unnecessary repairs.
- [Read and Clear More Codes Than Ever] Read and clear more codes than basic car code readers. Access enhanced diagnostics for Check Engine, ABS, SRS, Airbag, TPMS, Transmission.
- [Verified Fixes and Real-Time Data] Get unlimited, technician-verified repair reports matched to your VIN, with definitions, causes, and confirmed fixes. Monitor live vehicle data as you drive, view freeze frames, check smog readiness, and analyze Mode 6 test results.
- [Wireless & Bluetooth Enabled] - Say goodbye to wires. BlueDriver connects with Bluetooth via your phone/tablet to a sensor that plugs into your car's OBDII port. Get all of the capabilities of an expensive code reader & scan tool without any annoying wires.
- [Broad Make & Model Coverage] Strong support for GM, Ford, Stellantis (RAM, Jeep, Chrysler), Toyota, Honda, Nissan, Mazda, Subaru, Hyundai, Mercedes-Benz, BMW, and VW.
This product presentation was made with AAWP plugin.