[FIXED] No crank/no start 06 Cadillac DTS

06 Cadillac DTS...No crank, no start, no OBD2 communication. Power at port 16 on DLC. Port 4 and 5 test out fine. Last code reading detected bank 1 sensor 1 02 sensor. Right before no crank/no start, she drove perfectly. I parked, ran into house for paperwork, ran back out to no crank/no start. Since then, I have replaced both 02 sensors, crank and cam sensors, underhood fuse block, and BCM. I also replaced IMS, and still have same issue. One more problem I noticed a few weeks back was my ABS/Traction control lamp lit up a couple of times, but hasn't since. Any input would be greatly appreciated.

Is the engine control module the only module you can’t communicate with?? Do you have 5 volt reference at the maf sensor? Or tps sensor? I’d be checking powers and grounds with communication linesat pcm. Does pins 6 and 14 get used at dlc? Or just pin 2?

Hope someone puts up information bus diagram and stArting system diagram.

Thank you so much for responding, Cheryl. Initially, what created the barrage of system component replacements was the 5v reference checks. I remember getting 5 at one, but not another. At this point, I pulled the starter relay, and got crank but no start. There was no doubt about fuel pressure. After finding no voltage at the injector, I went after the CKP, which is beneath the intake. I pulled it and checked voltage, although primitive, with VOM and a spinning cog. I had no voltage. Replacing it made no difference. This is where I said screw it, and started replacing everything I found to be a problem. THAT turned out to be the bigger problem. I went to the internet and found you guys.

In re: lines 6 and 14. I haven't checked distribution, but will do that in the morning. I did check continuity to make sure there were no breaks between BCM, ECM and DLC and found all are okay. I'll let you know what I find.

JReardon...thank you so much for the schematics. Searching the internet for these things can be extremely difficult. I really appreciate you and Cheryl for reaching out.

So can you communicate with everything else besides the engine control module? If so we need to check powers grounds data lines to it. Need a diagram of engine management system

Check 5 volt reference 1 and 2 key on.

Hey, Cheryl. Okay, for starters, Boston weather will not cooperate, but I did pull my DLC and found something interesting...No pin 2. I have pin 1, 4, 5, 6, 7, 14, and 16. I'm searching for protocol and wiring color code as I write this, although I'm pretty sure this is major concerning the lack of communication between DLC and OBD2 scan. Jreardon sent diagrams, so I'm going to check those and go from there. In the pic below, that green line is in slot 1. The following four lines are 4, 5, 6, 7.

Does the check engine light come on when you turn the key to the on position?

What do you mean by 4 and 5 checked Ok... they are grounds, what test did you do and what results did you get. How did you get the starter to work with the relay removed?

As Cheryl said, check powers and grounds... look for the 5v reference to TPS, MAF ect… use the diagram jreardon supplied it shows which devices have a 5v reference. Being as you're in Boston, I'm betting on rust.

scannerjohn wrote: How did you get the starter to work with the relay removed?

+1

scannerjohn wrote: Being as you're in Boston, I'm betting on THE PATRIOTS.

Huh, me too

Go Knights Go...

I just found out what was wrong with this 06 DTS I had at the garage. Car came in with a dead battery. After charge the speed in the display was three dashes no “0”. The light under the “P” in the display was not lit.. No crank, Scan showed only comm with the BCM. From the wiring diagram, all these modules under hood communicate with tan wires that run from one to the other. What I did to get this car started was to jump pins 3 & 4 and 18 & 19 on the ABS module. For some reason the communicate stopped at that module. Once I bypassed this module by jumping those wires it started. I am assuming the ABS module is junk. This car also had a leaking water pump which is right over that module.

I know it's been a while, but I didn't want you guys to think I forgot about you.

First, SCANNERDANNER, you've got an amazing program, with an amazing crew. The simplicity of your approach is second to none...I thank you.

Cheryl, you lit the spark needed to get my Caddy going. I am eternally grateful. This is my little girl, and I don't want to let her go.

JReardon...those diagrams were unbelievable. In my eyes, you guys are nothing short of the best.

Bill's garage, you completed this team. My ABS was the culprit. I had those very same symptoms. After using JR's references, searching the correct values through that nightmare of a harness solved my problem. As stated above, this is my little girl, and I was leary about jumping those pins, but the values were way off. Replaced the module, and brought her back to life.

I bow to you guys.

Thank you...

I’m having this exact same problem with my 2007 Cadillac dts it’s not detecting that my car is in park similar to yours and won’t crank but when the car is on I can move the lever without my foot on the brake also I’m not sure where the abs module is located. Any help would be greatly appreciated.

Julian i think it is by right front wheel well on passenger side .

Appreciate it got it running today thanks for responding in timely fashion.