VIDEO

Informace

GMC

GMC P2149

See the basic definition of a diagnostic error. This will help you to clarify the main causes of the fault code. You will understand the program of the control unit
Basic DTC analysis according to OBD2 protocol standard.

OBD2 or On-Board Diagnostics displays messages for basic group styles. More comprehensible code composition has been standard since 2000. The DTC code consists of five characters and its composition will be shown in this video

Insight into programming

The basic unit for the operation of any computer is the bit. Logic 0 and 1 are expressed by a single bit. Diagnostics The error code is composed of 16 bits. The first two bits define one of the four basic circuits. The video will show you a comprehensive overview of the composition of the error report

A diagnostically understandable description of the Diagnostic Trouble Code

GMC P2149

Basic error definition

HECU Fault

Cause of DTC

Enable Conditions: Case 1: The electrical feedback signal does not match the actuation signal for the corresponding valve for more than 30 ms. Current controlled valves and under voltage conditions :detection time is 80 ms Case 2: A Fault is found if UVR is not within 0.1battery voltage lt; valve relay voltage lt; 0.8battery voltage A Fault is found if valve relay voltage ≥ 0.2battery voltage. After that all valves are switched on sequential, valve relay voltage and valve feedback is measured. Case 3: The valve and pump motor test detects electrical actuation malfunction of ABS valves. The test actuates all valves in series (to detect short cuts or shunts between the valve lines). Faults are detected if there is an error during the test. Case 4: The drift test is executed only once during an ignition Cycle. If it detects partly shorted valve coils, almost inoperative coils or malfunction of the valve driver, a failure is recognized.