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.
I noticed the powertrain fuse clicking continuously when tryI ngvto crank it but still won't start and the negative terminal stays a little loose when tightened all the way and now the battery just went way dow. On the charging Guage on the instrument panel it's in the negative a bout 1/4.
I charged the battery yesterday to a 100 % wonder why it went back down again ? I also put another good battery in it yesterday and it still didn't crank
The alternator isn't working . The charging system on your vehicle is computer controlled . This is something you should take to a qualified repair shop,
https://www.motor.com/magazinepdfs/09200...
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SOURCE: 2004 Chevy Tahoe - Reduced engine power message
have autzone check for any stored trouble codes, replace the fuel cap, make sure you have plenty of gas
SOURCE: The "engine power is reduced" light comes on
po455 is Probable Cause[s]
1. Defective, loose or missing fuel cap
2. EVAP canister broke, hose cracked or not connected
3. Purge or vent solenoid defective
4 . Vacuum leak at engine po121 code po121 means Throttle Position Sensor/Switch A Circuit Range/Performance Problem . it is usually indicative of a faulty throttle position sensor or faulty wiring harness in the engine bay.
SOURCE: reduced engine power on
The traction control uses the speed sensor in the transmission and the wheel speed sensors to determine wheel spin. If a wheel spins braking is applied to it so that the power can be transferred to the other wheels. At some point the ECU detected a gross disagreement between the sensors and so as a precaution has entered into a limp home mode. On some systems if the fault is in error it can be cleared by putting the car into drive and moving forward a meter, putting in reverse and going a back a meter and doing this three times. If one or other of the sensors are faulty this process will not allow the error to be cleared. You need to check or have checked the error codes and the speed sensors.
SOURCE: 2009 chevy silverado traction control
DTC P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
Your vehicle has an electronic throttle body unit so it uses voltage signals to control throttle blade in the throttle body. There are a few different issues that can cause this problem.
First off there is a update for the PCM to address those codes, but you will have to take it to the dealer for that.
Second there is issues with the actuator on the throttle body binding up and causing the codes.
Third there is a yellow wire coming off the throttle body connector that breaks inside internally and cannot be seen to the naked eye. The best way to test that is to grab the wire about 5 inches from the connector and tug if it feels spongy or breaks, that
SOURCE: I HAVE AN 08 CHEVY
May or may not have anything to do with the engine light, the traction control system is shut down due to the check engine light , whenever the computer sees the engine is not operating within specs it will turn on the engine light and also the trac light, the first thing to do is have the computer scanned to see what the codes are that are stored in the computer.there are many auto part stores that will scan it for free and give you a print out of the codes, if you can get the codes i can help you further but the codes are the first step.as far as the tires i dont think that has anything to do with it,it sounds like a bad sensor or maybe something got left off during the fluid repair , the codes will help in this. good day
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New battery new ground wires ,had starter checked it's fine , tahoe still will not turn over or even crank .Still making clicking sound at starter fuse in fuse panel . Traded out same size fuse and still made clickin noise ..
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