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HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 21 (BODY CONTROL MODULES)DIAGNOSTIC TESTSDTC U1300: CLASS 2 DATA LINK SHORTED TO GROUNDDESCRIPTION
1999 GMC Forward Control 5.7 R, Automatic

DTC U1300: Class 2 Data Link Shorted To Ground: Description

1999 GMC Forward Control 5.7 R, AutomaticSECTION Description
WARNING: This page is about a different car, the 2002 Chevrolet Monte Carlo, 2002 Chevrolet Impala, 2001 Chevrolet Monte Carlo, and 2001 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

Modules connected to class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among modules. In addition to this, state of health messages are transmitted by each module on class 2 serial data circuit about once every 2 seconds. When a module detects no serial data messages and a low voltage on class 2 serial data circuit for about 3 seconds, U1300 is set. Setting of all other class 2 serial communication DTCs is inhibited.

DTC U1300 is set when, no valid messages are detected on class 2 serial data circuit. Voltage level detected on class 2 serial data circuit is low. Conditions are met for about 3 seconds.

When DTC U1300 is set, module inhibits setting of all other class 2 DTCs. Module uses default values for all parameters received on class 2 serial data circuit.

Current DTC U1300 will clear and become a history DTC when a valid class 2 message is detected on class 2 serial data circuit or at end of current ignition cycle. History DTC U1300 will clear after 100 ignition on/off cycles with no repeat of malfunction.

RENDER: 1.0x

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