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2013 buick regal 2.0 turbo with about 340,000 on the clock. It has sat for about a year ran good when parked. Wanted to use the car changed the battery and it won't start and is littered with codes. Cleared the codes and get P1682 and P0689 just with ingition turned on (has push button start with keyless entry) started checking fuses and half the box is dead. Tracked that down to 2 relays not working ignition main and engine controls ignition relays switched relays with another with the same result so I'm guessing the relays are good. Started checking power to the relays and the ignition main as batt V on pins 30 and 85 but the engine controls ignition which is hot in on or start has batt V in 3 (30) but only .64V on 2 (86). I have both the engine performance and power distribution wiring diagrams for reference but not sure where to go from here because nothing really says where that pin 86 gets power.
Even with the key on (button pushed with out stepping on the brake) KR73 does not turn on all the fuses that are tied to it don't have power. This is my first time trying to figure out automotive electronics so I might be a little slow on things.
With the FOB in the car and the brake pedal pushed press the start switch once and release it, the dash should power up, does the Anti-theft warning indicator turn off?
If the theft light goes out, you can check if the Black Connector at the BCM X4 Pin 15 is providing power when when the Push Button is pressed with
a test lamp connected to a good ground and back-probing the wire. The BCM supplies B+ to turn the relay on.
If you don't have B+ when the Push button is pressed, you may have Ignition Switch issues.
You can however, put your test lamp on B+ and touch the wire at X4 pin 15 and see if it starts.
Finally got back on the car. Pin 15 on X4 lights the test light nice and bright. What is the easiest way to check the wire itself? If the wire is good does that mean the fuse block is bad?
So power is leaving the BCM, just not making it to the fuse box to turn on the relay.
The wire can be open (broke) or shorted to ground.
KeyOFF. Un plug the bcm connector and the relay, attach a test light to ground. Verify the light lights on a known good power source, gently touch pin 15.
Does the lamp light? If it lights, the wire is shorted somewhere between that point and the relay. It doesn't light the wire is broken somewhere between those two points.
Checked pin 15 on X4 (at the BCM) which is what I thought you were talking about until I realized the photos don't show up on my phone. Just checked pin 15 on X2 in the fuse box, but there is nothing in pin 15 so did pin 14 (it's also labeled the same) and in both places I get no light on the test light. Just so I understand what I'm doing by these checks. Where is X2 pin 15 getting power from to be checking with a test light to ground with the BCM unplugged and key off? Don't that wire get it's power from the BCM key on?
Yes that wire gets its power key on, I was under the understanding you did have power there Key on, but not at the relay!!
The relay is power side switched from the BCM. At the relay (removed) the two small pins are the control side. One pin is a constant ground; you can identify it with a test lamp to battery positive, the other should have power when the BCM sends it.
I had you disconnect at x15 bcm to test if that wire is shorted to ground, because you would be applying B+ to it from the fuse panel.
At the BCM that pin 15 has power with the key on (didn't check the voltage but enough to light the test light) but at the relay there is only .64V not 12V which I am guessing the relay needs to switch on. So I should be able to plug the BCM back in and turn on the key and have 12V at pin 15 on the X2 connector. If that is true the there would be something in the fuse block messed up. Am I thinking right?
That 0.64 volts Is why I wanted you to unplug the BCM. then you could put the test light to battery positive and touch that wire at the fuse box to see if it lights. if it lights there is a short to ground somewhere between the fuse box and the BCM. if it doesn't light, the wire is broker open.
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