Sierra, Silverado 2006-2007

6.0L V8 VIN N Auto 13

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Trouble Code: U1001



Serial Data Communications Failure

Possible Causes:



An intermittent open between a module and a star connector may cause this DTC to set.
 
A poor connection at a module or a star connector may cause this DTC to set.
 
An intermittent open in a star connector may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1254



Lost Communication with XXX

Possible Causes:



An intermittent open between a module and a star connector may cause this DTC to set.
 
A poor connection at a module or a star connector may cause this DTC to set.
 
An intermittent open in a star connector may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1300



Class 2 Data Link Low

Possible Causes:



These DTCs cannot be retrieved with a current status. Diagnosis of current DTC is accomplished via the symptom, Scan Tool Does Not Communicate with a Class 2 Device. Refer to Scan Tool Does Not Communicate with Class 2 Device .
 
An intermittent condition is likely to be caused by a short on the class 2 serial data circuit. Use the Scan Tool Does Not Communicate with a Class 2 Device procedure in order to isolate an intermittent condition. Refer to Scan Tool Does Not Communicate with Class 2 Device .
 

Trouble Code: U1301



Class 2 Data Link High

Possible Causes:



These DTCs cannot be retrieved with a current status. Diagnosis of current DTC is accomplished via the symptom, Scan Tool Does Not Communicate with a Class 2 Device. Refer to Scan Tool Does Not Communicate with Class 2 Device .
 
An intermittent condition is likely to be caused by a short on the class 2 serial data circuit. Use the Scan Tool Does Not Communicate with a Class 2 Device procedure in order to isolate an intermittent condition. Refer to Scan Tool Does Not Communicate with Class 2 Device .
 

Trouble Code: U1305



Class 2 Data Link Low or High

Possible Causes:



These DTCs cannot be retrieved with a current status. Diagnosis of current DTC is accomplished via the symptom, Scan Tool Does Not Communicate with a Class 2 Device. Refer to Scan Tool Does Not Communicate with Class 2 Device .
 
An intermittent condition is likely to be caused by a short on the class 2 serial data circuit. Use the Scan Tool Does Not Communicate with a Class 2 Device procedure in order to isolate an intermittent condition. Refer to Scan Tool Does Not Communicate with Class 2 Device .
 

Trouble Code: U1500



Inter-Device Dedicated Bus Malfunction

Possible Causes:



The diagnostic procedure used for DTC U1500 in OnStar® systems with single module generations of OnStar® differ greatly from previous generations with 2 modules. While these older generations denoted a failure of the 3-wire bus between the modules by setting a U1500, single module OnStar® systems use this DTC to denote an internal module failure. The determination of whether a one or 2-module generation of OnStar® is used should be confirmed. Refer to OnStar Description and Operation .
 
This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the VCIM.
 
If this DTC is retrieved as both a current and history DTC, replace the VCIM.
 

Trouble Code: U1881



Electro-Hydraulic Power Steering (EHPS) Module Lost Communication With Energy Storage Control Module (ESCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1882



Energy Storage Control Module (ESCM) Lost Communication With Electro-Hydraulic Power Steering (EHPS) Module

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1883



Hybrid Control Module (HCM) Lost Communication With Driver Door Module (DDM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1884



Hybrid Control Module (HCM) Lost Communication With Passenger Door Module (PDM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1885



Energy Storage Control Module (ESCM) Lost Communication With Hybrid Control Module (HCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1886



Energy Storage Control Module (ESCM) Lost Communication With Powertrain Control Module (PCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1887



Energy Storage Control Module (ESCM) Lost Communication With Starter/Generator Control Module (SGCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1888



Hybrid Control Module (HCM) Lost Communication With Energy Storage Control Module (ESCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1889



Hybrid Control Module (HCM) Lost Communication With Body Control Module (BCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1890



Hybrid Control Module (HCM) Lost Communication With HVAC Control Module

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1891



Hybrid Control Module (HCM) Lost Communication With Instrument Panel Cluster (IPC)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1892



Hybrid Control Module (HCM) Lost Communication With Electro-Hydraulic Power Steering (EHPS) Module

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1893



Hybrid Control Module (HCM) Lost Communication With Powertrain Control Module (PCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1894



Hybrid Control Module (HCM) Lost Communication With Starter/Generator Control Module (SGCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1895



Electro-Hydraulic Power Steering (EHPS) Module Lost Communication With Powertrain Control Module (PCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1896



Electro-Hydraulic Power Steering (EHPS) Module Lost Communication With Starter/Generator Control Module (SGCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1897



Starter/Generator Control Module (SGCM) Lost Communication With Energy Storage Control Module (ESCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1898



Starter/Generator Control Module (SGCM) Lost Communication With Hybrid Control Module (HCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

Trouble Code: U1899



Starter/Generator Control Module (SGCM) Lost Communication With Powertrain Control Module (PCM)

Possible Causes:

Important:



For DTC U1892, ensure all power and ground circuits to the electric-hydraulic power steering (EHPS) module including the motor are tested. A loss of voltage or ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication.
 
DTCs U1883 and U1884 can be set inadvertently, when braking during the trailer towing. If only these codes are set as history only, clear the codes.
 
An intermittent open between a module and a star connector may cause this DTC to set.
 
An intermittent open on high speed GMLAN may cause this DTC to set.
 
An open voltage or ground circuit to a module may cause this DTC to set.
 
An internal module malfunction may cause this DTC to set.
 

 
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