redddog

Okay I have a 2007 Tahoe LS 5.3 has 2xx,xxx miles on it. I’ve been reading just about every thread I can find about the no start no crank that I can find, but only a few of them will have a small part of the issues I’ve been having not all of it. So for example all the lights work they don’t go crazy, door locks work with or with out key fob, checked every negative battery connection under the hood, check the master fuse, swapped relays checked voltage to starter. I even found where someone suggested the rear glass switch could possibly cause some issues. So I replaced that… which it needed to be done anyways. I haven’t check fuel rails or ignition switch. I’ve also tried the relearn key fob thing along with the relearn key trick. Nothing.

So what I have to do is sit in my truck with the key turned on for about 8-10 minutes before it will even crank and start. I put in some new speakers a few months ago but this started about a month after that. My wife locked my son in the car on day while I was out of town working and a cop jimmied the door. She also almost pulled every door handle off thinking that might help. smh I know but the handles are still intact and work fine.

repairman54

With your high mileage it could be something simple like a worn out ignition switch. Lots of power and signals are controlled by it.Power Mode Description and Operation

Serial Data Power Mode Master

Power to many of this vehicles circuits is controlled by the module that is designated the power mode master (PMM). This vehicles PMM is the body control module (BCM). The ignition switch is a low current switch with multiple discrete ignition switch signals to the PMM for determination of the power mode that will be sent over the serial data circuits to the other modules that need this information. The PMM will also activate relays and other direct outputs of the PMM as needed. The PMM determines which power mode (Off, Accessory, Run, Crank Request) is required, and reports this information to other modules via serial data. Modules which have switched voltage inputs may operate in a default mode if the PMM serial data message does not match what the individual module can see from its own connections.

The PMM receives ignition switch signals to identify the operators desired power mode. The PMM Power Mode Parameters table below illustrates the correct state of these input parameters (circuits) in correspondence to the ignition switch position:




Relay Controlled Power Mode

The body control module (BCM) uses the discrete ignition switch inputs Run/Crank Ignition 1 Voltage, Accessory Voltage, and Ignition 1 Voltage, to distinguish the correct power mode. The BCM, after determining the desired power mode, will activate the appropriate relays for that power mode.

The RAP relay remains on for a timed period after the Ignition key is removed. Refer to Retained Accessory Power Description and Operation See: Retained Accessory Power for more information on the retained accessory power (RAP) function.