Engine not starting properly and battery drains out overnight

Hi,

Can you tell me exactly what is happening? Also, has anyone scanned for diagnostic trouble codes? I'm not sure exactly what is happening, but if there is a starting issue and you have to wait for the dash lights to work, we need to see what is creating the delay.

In this case, I would scan the can-bus system. CAN stands for controller area network. Basically, all the modules/computers are tied together via a few wires. This type of scan will identify the codes regardless of the module/computer they are stored in. Here is a video showing how it's done.

https://youtu.be/InIlnsjOVFA

Let me know if this has already been done and if codes were found. If possible, let me know the codes that were retrieved. Also, let me know as much as possible of what you experience.

Take care,

Joe

the car battery drains if i do not start it during that time. after i jump the car can turn key all the way to right and nothing happens if i put it in accessory position and wait for dash lights it starts they ran diagnostics at chevy dealer they said it was 1 or more 0f 5 modules driver's door mod (ddm)or dash integration module (dim) or powertrain control mod (PCM)or RFA mod or rear integration mod or VTD passkey mod he said he could throw parts at it or i could pick car up as is i needed car back after 3 weeks without it.

after i jumpstart car dah light check gauges and tire reset come on and gas gauge does not work; shows empty after a litlle while of driving it slowly moves up from e.

Hi,

I would think they could have narrowed it down a bit for you. There are a couple of the modules you mentioned that wouldn't cause it. I know the PCM is tied into it. I also know the CAN system is tied into it.

By any chance, does their receipt have the diagnostic trouble codes they found? Also, you mentioned that "The car battery drains if I do not start it during that time." What time are you referring to?

When the lights turn back on, do they just start working normally or does it slowly go from dim to bright?

I attached the wiring schematic below for the starting system. I highlighted a few things. First, the starter relay. Do me a favor. Remove it and inspect the connections in the box for corrosion or damage. Next, if you look at pic 2, I highlighted the wiring for the computer data lines. That is part of the CAN system. CAN stands for controller area network. If they scanned the CAN, it should be a little more specific than just one of five modules. That's why I asked if the codes are listed on the receipt.

One other thing of interest. The starter relay is powered off a circuit breaker and not a traditional fuse. Something could be causing issues there as well.

Let me know if they included the codes that were found. Also, let me know if you are able to have the can-bus scanned.

Let me know.

Joe

See pics below. Note: the wiring schematic was one page long. I had to cut it in half to make it readable for you. Pic 3 shows the starter relay and the circuit breaker I mentioned. These are in the under-hood fuse box.

the time i was referring to is when i jump the car and let it charge battery if i turn it off and restart it works for a couple hours but if i do not keep restarting and charge battery it drains empty in about 6 hours maybe less time as far as codes i do not see any on the diagnostic system check theft deterrent it states there was a lack of communication which may be due to a partial malfunction of the class 2serial data circuit odue to total malfunction. the presence of DTCs U1161.U1162,U1163 or U1170 indicate 1 or more of the door modules is not communicating on the sbi circuits the presence of DTCs which begin with U indicate some other module is not communicating.

Hi,

Let's try to narrow things down. Basically, I need you to do a test for a parasitic draw.

Disconnect the negative battery terminal. Connect a voltmeter between the neg terminal (+ side of the multimeter) and the other wire (negative on the multimeter) to the neg battery post. Then, remove one fuse at a time from the under-hood fuse box to see what stops the battery draw.

Here is a link you may find helpful:

https://www.2carpros.com/articles/car-battery-dead-overnight

Let me know what you find.

Joe