My 08 Chevy Tahoe with 56k on it lost all power as I was driving I tried to crank it back up but it wouldn't start. Stable track, traction control , engine light reduced power on.Changed battery nada
Do you know anything about automotive electrical testing ? Do you know what it takes for your vehicle to start ? When you trun the key to start what happens ? The electronic's involved ? The ignition switch is a input to the BCM - body control module . When the key is turned to the start position the BCM see's that an then sends a coded message to the ECM - engine computer.over the serial data bus or network ! which will then energize the starter relay , located in the under hood fuse box . This will only happen if the ECM see's the input from the transmission range sensor , telling the PCM the vehicle is in park or neutral. an there isn't any problem with the anti- theft system . Plus all the other basic problems that can cause a no crank no start condition . Battery , battery connections , battery cables etc... Low Voltage will cause warning lights to come on , telling the driver those systems are disabled . The best thing you could do , have a qualified repair shop hook up a professional scan tool an check for DTC'S .
Circuit Description (Key Start)
When the ignition switch is placed in the Start position, a discrete 12-volt signal is supplied to the body control module (BCM) notifying it that the ignition is in the Start position. The BCM then sends a message to the engine control module (ECM) notifying it that CRANK has been requested. The ECM verifies that the transmission is in Park or Neutral. If it is, the ECM then supplies 12 volts to the control circuit of the STRTR relay. When this occurs, battery positive voltage is supplied through the switch side of the STRTR relay to terminal S of the starter solenoid.
Also if the charging system was not working properly the Computers on the vehicle would shut thing's down if the BCM see's low output from the alternator .
Electrical Power Management
The electrical power management (EPM) is used to monitor and control the charging system and alert the driver of possible problems within the charging system. The EPM system makes the most efficient use of the generator output, improves the battery state of charge (SOC), extends battery life.
The idle boost operation is a means of improving generator performance during a low voltage or low battery SOC condition.
Idle boost is activated in incremental steps, idle boost 1 must be active before idle boost 2 can be active. The criteria used by the body control module (BCM) to regulate EPM are outlined below.
Feb 25, 2017 |
2008 Chevrolet Tahoe