What is P0101 lost communication with transfer case control module ?

Hooking up a factory or someother type professional scan tool an checking for DTC'S - diagnostic trouble codes stored in the 4X4 control module is the proper way to start diagnostics . Your best bet ,have a qualified repair shop check it out .

Principles of Operation
The electronic shift on the fly (ESOF) system is an electronic shift system that allows the operator to choose between 2 different 4-wheel drive modes as well as 2-wheel drive. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal pressed and the transmission must be in NEUTRAL (or the clutch pedal pressed in manual transmission vehicles).
When the mode select switch (MSS) on the instrument panel is turned, the 4WD control module (PCM) activates the electromagnetic clutch and powers the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the 4WD control module (PCM), power to the shift motor will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.

Feature Inputs:
• Mode select switch (MSS)
• Wheel speeds (via CAN communication)
• Contact plate position inputs A, B, C, D (grounded when closed, open circuit when open)
• Transmission neutral
• Brake ON/OFF (BOO)

Feature Outputs:
• Transfer case synchronization clutch
• Transfer case shift motor relays
• Integrated wheel-end (IWE) vacuum solenoid
• Instrument cluster indicators (via CAN communication)
• 4WD mode (via CAN communication to PCM)
• Inspection and Verification
  
  1. Verify the customer concern.
  1. Visually inspect for obvious signs of mechanical or electrical damage.
  
  
  Visual Inspection Chart Mechanical Electrical
  • Halfshafts
  • Integrated wheel ends (IWE)
  • Shift motor
  • Driveshaft and universal joints
  • Vacuum leaks
  • Fluid leaks
  • Matching tire sizes
  • Transfer case
  • Central junction box (CJB) mini fuses:
    • 11 (10A) (IWE vacuum solenoid)
    • 28 (5A)
    • 29 (15A)
    • 30 (15A)
  • CJB fuse 111 (20A)
  • Wiring harness
  • Mode select switch (MSS)
  • Synchronization clutch
  • Connector(s)
  • IWE vacuum solenoid
  • Circuitry
  
  
  1. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
  1. If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
  • check that the program card is correctly installed (if using NGS+).
  • check the connections to the vehicle.
  • check the ignition switch position.
  1. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
  1. Carry out the data link diagnostics test. If the diagnostic tool responds with:
  • SCP+, SCP-, UBP, CAN or ISO circuits fault; all electronic control units no response/not equipped, refer to Section 418-00 .
  • No response/not equipped for powertrain control module (PCM). Refer to Section 418-00 to diagnose module communication problems.
  • No response/not equipped for 4WD control module (PCM), Go To Pinpoint Test J .
  • System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the 4WD control module (PCM).
  1. If the DTCs retrieved are related to the concern, go to the 4WD Control Module (PCM) DTC Index to continue diagnostics.
  1. If no DTCs related to the concern are retrieved, GO to Symptom Chart .
  2. 4WD Control Module (PCM) Diagnostic Trouble Code (DTC) Index
     DTC Description Source Action B1317 Battery Voltage High 4WD Control Module (PCM) CHECK the battery and charging system for faults. REFER to Section 414-00 . CLEAR the DTC. REPEAT the self-test. B1318 Battery Voltage Low 4WD Control Module CHECK the battery and charging system for faults. REFER to Section 414-00 . CLEAR the DTC. REPEAT the self-test. B1342 ECU is Defective 4WD Control Module CLEAR the DTC. REPEAT the self-test. If DTC B1342 is retrieved, INSTALL a 4WD control module (integral to the PCM). REFER to Section 303-14 . REPEAT the self-test. C1728 Transfer Case Unable to Transition Between 2WD HIGH and 4WD HIGH 4WD Control Module Go To Pinpoint Test L . C1729 Transfer Case Unable to Transition Between 4WD HIGH and 4WD LOW 4WD Control Module Go To Pinpoint Test M . C1979 IWE Solenoid Circuit Failure 4WD Control Module Go To Pinpoint Test K . C1980 IWE Solenoid Circuit Short to Battery 4WD Control Module Go To Pinpoint Test K . P1812 Transmission 4-Wheel Drive Mode Select Circuit Failure 4WD Control Module Go To Pinpoint Test L . P1815 Transmission 4-Wheel Drive Mode Select Short Circuit to Ground 4WD Control Module Go To Pinpoint Test L . P1820 Transfer Case Clockwise Shift Relay Coil Circuit Failure 4WD Control Module Go To Pinpoint Test L . P1822 Transfer Case Clockwise Shift Relay Coil Short Circuit To Battery 4WD Control Module Go To Pinpoint Test L . P1824 Transmission 4-Wheel Drive Clutch Relay Circuit Failure 4WD Control Module Go To Pinpoint Test N . P1826 Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Battery 4WD Control Module Go To Pinpoint Test N . P1827 Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Ground 4WD Control Module Go To Pinpoint Test N . P1828 Transfer Case Counterclockwise Shift Relay Coil Circuit Failure 4WD Control Module Go To Pinpoint Test L . P1830 Transfer Case Counterclockwise Shift Relay Coil Short Circuit To Battery 4WD Control Module Go To Pinpoint Test L . P1849 Transmission Transfer Case Contact Plate A Short Circuit to Ground 4WD Control Module Go To Pinpoint Test L . P1853 Transmission Transfer Case Contact Plate B Short Circuit to Ground 4WD Control Module Go To Pinpoint Test L . P1857 Transmission Transfer Case Contact Plate C Short Circuit to Ground 4WD Control Module Go To Pinpoint Test L . P1861 Transmission Transfer Case Contact Plate D Short Circuit to Ground 4WD Control Module Go To Pinpoint Test L . P1867 Transmission Transfer Case Contact Plate General Circuit Failure 4WD Control Module Go To Pinpoint Test L . P1891 Transmission Transfer Case Contact Plate Ground Return Open Circuit 4WD Control Module Go To Pinpoint Test L . U1900 CAN Communication BUS Fault - Received Error 4WD Control Module DIAGNOSE the module communication network. REFER to Section 418-00 . U2023 Fault Received From External Node 4WD Control Module DIAGNOSE the module communication network. REFER to Section 418-00 . U2051 One Or More Calibration Files Missing/Corrupt 4WD Control Module Method 3 programming fault. REFER to Section 418-00 for 4WD control module (PCM) programming information.

HDM module ??????? No such module .
DTC U0100 00: Lost Communication With Engine/Powertrain Control Module (ECM/PCM)
DTC U0101 00: Lost Communication With Transmission Control Module (TCM)
DTC U0121 00: Lost Communication With Electronic Brake Control Module (EBCM)
DTC U0140 00: Lost Communication With Body Control Module (BCM)
DTC U0151 00: Lost Communication With Restraints Control Module
DTC U0155 00: Lost Communication With Instrument Panel Cluster (IPC) Control Module
DTC U0164 00: Lost Communication With HVAC Control Module
DTC U0168 00: Lost Communication With Vehicle Theft Deterrent (VTD) Control Module
DTC U0170 00: Lost Communication With Passenger Presence System (PPS)
DTC U0184 00: Lost Communication With Radio
DTC U0186 00: Lost Communication With Audio Amplifier
DTC U0194 00: Lost Communication With Digital Radio Receiver (DRR)
DTC U0198 00: Lost Communication With Communication Interface Module (OnStar®)
DTC U0209 00: Lost Communication With Heated Seat Module (HSM)
DTC U0214 00: Lost Communication With Remote Function Actuation (RFA)

These are all the modules onyour vehicle - no hdm module .

C0292
Lost Communications with Engine Control System
EBCM
DTC C0290 or C0292 in Antilock Brake System
Your best bet ! Take it to a quaified repair shop . Do you know what Class 2 data bus is ?

Class 2 Serial Data Line
The class 2 serial data line on this vehicle is a star configuration. The following modules communicate on the class 2 serial data line:
• Audio Amplifier, w/UQ7 and Y91
• Body Control Module (BCM)
• CD Changer (CDX), w/U1S and Y91
• Digital Radio Receiver (DRR), w/U2K or U2L
• Driver Door Module (DDM)
• Driver Seat Module (DSM), w/AN3
• Electronic Brake Control Module (EBCM)
• Electronic Suspension Control (ESC) Module, w/Z55
• Front Passenger Door Module (FPDM)
• Generator Battery Control Module (GBCM)
• HVAC Control Module
• HVAC Control Module - Rear Auxiliary
• Instrument Panel Cluster (IPC)
• Powertrain Control Module (PCM)
• Radio
• Rear Seat Audio (RSA) Controller, w/UK8
• Rear Seat Entertainment (RSE) Assembly, w/U42
• Rear Wheel Steering Control Module (RWSCM)
• Inflatable Restraint Sensing and Diagnostic Module (SDM)
• Transfer Case Shift Control Module (TCSCM), w/NP1/NP8
• Vehicle Communication Interface Module (OnStar), w/UE1
• Vehicle Theft Deterrent (VTD) Module, w/VD1
The class 2 serial data line allows a scan tool to communicate with these modules for testing purposes, checking for DTCs, and to activate/enable/disable functions. These class 2 serial data circuits are bused together via three splice packs and DLC:

Need to have it check for DTC'S - diagnostic trouble codes , see if a scan tool will communicate with it , see if it will show data PID'S .
SERVICE indicator (4WD/AWD) Lamp
The SERVICE indicator (4WD/AWD) lamp is an integral part of the cluster and cannot be serviced separately. This lamp is used to inform the driver of the vehicle of malfunctions within the automatic transfer case (ATC) system. The SERVICE indicator (4WD/AWD) lamp is controlled by the transfer case shift control module via CKT 1567.

Is your service indicator lamp lit ?
which of these does your jimmy have
Transfer Case - NVG 233-NP1 (Two Speed Selectable)
Transfer Case - NVG 236 (Two Speed Automatic)

What large square fuse ? The 4X4 switch get's it's B+ voltage from the four - wheel drive control module . computer controlled ! Has two relay's - transfercase hi to low & low to high ,located in the Auxiliary relay box #3 . location left side of radiator core support . Your best bet ,take it to a qualified repair shop that has a diagnostic tool that can communicate with the 4X4 control module . Read code's ! Probably has a code like one of these
P1812 Transmission 4-Wheel Drive Mode Select Circuit Failure 4WD control module Go To Pinpoint Test D . P1815 Transmission 4-Wheel Drive Mode Select Short Circuit to Ground 4WD control module Go To Pinpoint Test A .
But code have a few others as well .
B2105 Throttle Position Input Out of Range Low 4WD control module Go To Pinpoint Test B . B2106 Throttle Position Input Out of Range High 4WD control module Go To Pinpoint Test B . C1728 Transfer Case Unable to Transition Between 2H and 4H. 4WD control module Go To Pinpoint Test C . C1729 Transfer Case Unable to Transition Between 4WD HIGH and 4WD LOW 4WD control module Go To Pinpoint Test D . C1979 IWE Solenoid Circuit Failure 4WD control module Go To Pinpoint Test F . C1980 IWE Solenoid Short to Battery 4WD control module Go To Pinpoint Test F . P1812 Transmission 4-Wheel Drive Mode Select Circuit Failure 4WD control module Go To Pinpoint Test D . P1815 Transmission 4-Wheel Drive Mode Select Short Circuit to Ground 4WD control module Go To Pinpoint Test A . P1824 Transmission 4-Wheel Drive Clutch Relay Circuit Failure 4WD control module Go To Pinpoint Test A . P1826 Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Battery 4WD control module Go To Pinpoint Test A . P1827 Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Ground 4WD control module Go To Pinpoint Test A . P1849 Transmission Transfer Case Contact Plate A Short Circuit to Ground 4WD control module Go To Pinpoint Test D . P1853 Transmission Transfer Case Contact Plate B Short Circuit to Ground 4WD control module Go To Pinpoint Test D . P1857 Transmission Transfer Case Contact Plate C Short Circuit to Ground 4WD control module Go To Pinpoint Test D . P1861 Transmission Transfer Case Contact Plate D Short Circuit to Ground 4WD control module Go To Pinpoint Test D . P1867 Transmission Transfer Case Contact Plate General Circuit Failure 4WD control module Go To Pinpoint Test D . P1891 Transmission Transfer Case Contact Plate Ground Return Open Circuit 4WD control module Go To Pinpoint Test D .

Perhaps, but check all wiring, fuses first.

a bad module will do this try unplugging it and plugging it back in, find a scanner that will talk to the 4x4 module not just the PCM.

P240D The current transfer case sent from control unit N78(Transfer case control module)via
the CAN bus is implausible.
P240D There is a sporadic fault in CAN communication with control module N78 (Transfer
case control module) or the transfer case position is sporadically implausible
P2213 Nitrogen oxides (NOx) sensor,bank2-circuit malfunction (probly cause wiring NOx sensor.

you need to replace the tccm and get it programmed.


2-04-21-006E: Inoperative 4WD/AWD Lamps, Inoperative 4WD/AWD System, DTC C0550 Set No Communication with TCCM (Reprogram Transfer Case Control Module) - (Jul 20, 2006)
Subject: Inoperative 4WD/AWD Lamps, Inoperative 4WD/AWD System, DTC C0550 Set, No Communication with TCCM (Reprogram Transfer Case Control Module) Models: 2004 Buick Rainier 2002-2004 Chevrolet TrailBlazer, TrailBlazer EXT 2003-2004 Chevrolet Avalanche, Silverado, Suburban, Tahoe 2002-2004 GMC Envoy, Envoy XL 2003-2004 GMC Sierra, Yukon, Yukon XL 2004 GMC Envoy XUV 2002-2004 Oldsmobile Bravada with Electronic Shift or Active Transfer Case (RPOs NP1, NP4 or NP8)

This bulletin is being revised to add Subject information and change the labor operation. This bulletin cancels and supersedes Bulletin Number 03-04-21-006. Please discard Corporate Bulletin Numbers 02-04-21-006D and 03-04-21-006 (Section 04 -- Driveline/Axle).
ConditionSome customers may comment that the 4WD/AWD indicator lights on the selector switch do not work, or the 4WD/AWD system may be inoperative and/or the service 4WD light is illuminated. The condition is typically intermittent and always occurs at key-up. Upon investigation, the technician may find DTC C0550 set.
CauseThe Transfer Case Control Module (TCCM) has not received the wake-up call during key-up and has remained in the "sleep mode".
When the TCCM is in the "sleep mode", it will not communicate with the class II bus or the Tech 2®.
Correction

1. Try to communicate with the TCCM. If no communication, go to step 2. If communication is possible, go to step 5.
2. Remove the underhood (ATCM or TREC) TCCM fuse.
3. Wait 30 seconds.
4. Reinstall the fuse. The module should "wake up" and communicate with the Tech 2®.
5. Check for codes in the TCCM. If a C0550 is found current or in history with or without other codes, replace the module and go to step 6.
6. Reprogram the TCCM with the latest TIS software using normal SPS procedures.
7. Verify operation and that no codes are present.

Important: For the 2002 model year, the TCCM must be replaced and reprogrammed.
Warranty Information

break down of the codes is

po303 - that would be a misfire on cylinder 3
uo101 - cant communicate with TCM
uo107 - lost communication with throttle actuator control module