No OBD2 and Crank No Start

ZLCHAPO

Member
I picked up chasis #101 from a friend about a month and a half ago who started the project then lost interest. The donor was a 2006 SS SC. He had already started on the harness so I was kinda behind the 8 ball from the start but I thought after reading post, diagrams, and pin outs I had her close but apparently I do not. The OBD2 port has power and ground but will not connect to my scanner and the car will crank and crank but never try to fire, the plugs aren’t even wet (bled the rail several times so I know it has fuel). I tried to jump the starter with the key on to bypass the high speed data with no luck. Any help or direction would be great!
 

Traé

Goblin Guru
When the key is cycled on, does the fuel pump prime, throttle body can be moved with the pedal, and information is present on the digital HUD?
Or does the HUD show “- - - - - - - - - - - -“?
 

ZLCHAPO

Member
When the key is cycled on, does the fuel pump prime, throttle body can be moved with the pedal, and information is present on the digital HUD?
Or does the HUD show “- - - - - - - - - - - -“?
Yes, yes, and yes. It used to display “low coolant” and “engine power reduced” but now only displays “low coolant” but that’s because it is. I don’t have my button panel hooked up to cycle through the cluster because the previous owner must’ve cut the green wire for the “back” button because I never saw it, but that’s a project for later. Now, of the two switches on the clutch I only have the bottom one connected because the connector for the top was gone when I got the harness. I can reach down and hold the button on the lower switch and that will allow the engine to crank so i imagine the top switch is for the cruise control deactivation. Dont know how important any of that information is to you but want to give you the best idea of what’s going on
 

Gtstorey

Goblin Guru
Check the high speed data network status per this post;

 

ZLCHAPO

Member
Check the high speed data network status per this post;

It shows 60.7 ohms with the key off.
 

Traé

Goblin Guru

If you are not reading anything on pin 2 this wire may have been removed. It is not mentioned in any of the videos and I luckily stumbled across it while researching while hyping myself up to do the harness myself.
 

ZLCHAPO

Member

If you are not reading anything on pin 2 this wire may have been removed. It is not mentioned in any of the videos and I luckily stumbled across it while researching while hyping myself up to do the harness myself.
No sir it’s there, I traced it all the way to the pcm. It has continuity the whole way but no voltage on it when it’s connected to the pcm with the key on
 

Traé

Goblin Guru
No sir it’s there, I traced it all the way to the pcm. It has continuity the whole way but no voltage on it when it’s connected to the pcm with the key on
Hmmmm, do you have most of the car together? I believe that there are some components that need plugged in to get the car to start. I made sure to have the turn signal stalk, the security ring (VATS) around the ignition plugged in and some other things. I actually cranked my engine while it was outside of the goblin before fully wrapping my harness just to make sure I did it right. I was having issues with it not even wanting to crank and I checked everything that you did. Mine ended up being one of the swappable connectors I sent to you, and my starter relay was loose in my fuse box.

Sorry for the long-winded answer and not being able to help you out. I am all out of ideas.
I will be keeping an eye on this to see what the resolution is as it has me intrigued. This is interesting seeing a lot of the symptoms I had but not having the same fix and it cranks. Could your injector fuse be blown?
 

ZLCHAPO

Member
Hmmmm, do you have most of the car together? I believe that there are some components that need plugged in to get the car to start. I made sure to have the turn signal stalk, the security ring (VATS) around the ignition plugged in and some other things. I actually cranked my engine while it was outside of the goblin before fully wrapping my harness just to make sure I did it right. I was having issues with it not even wanting to crank and I checked everything that you did. Mine ended up being one of the swappable connectors I sent to you, and my starter relay was loose in my fuse box.

Sorry for the long-winded answer and not being able to help you out. I am all out of ideas.
I will be keeping an eye on this to see what the resolution is as it has me intrigued. This is interesting seeing a lot of the symptoms I had but not having the same fix and it cranks. Could your injector fuse be blown?
Oh you’re good, I appreciate all the help you, Gtstorey, and Ross have been! The only things I don’t have hooked up are the lights themselves (headlight, turn, rear), panel buttons, and the fans for the radiator and heat exchanger. The harness is all laid in there unwrapped but zip tied up neatly because I figured I’d run into some trouble after having to put a couple wires back in that the previous owner had cut out. Three were actually the two high speed data wires from the pcm then one low speed from the bcm that went to the big junction block. I did also check the injector fuse and it’s good.
 

Gtstorey

Goblin Guru
If you have a scanner that only reads p-codes.(only connects to ECM) and you have the 60 ohms reading on the data wires, it sounds like the ECM isn’t broadcasting. Check a wiring diagram/pinout to confirm that you are getting power and ground at all of the ECM wires that should have power and ground.
 

ZLCHAPO

Member
If you have a scanner that only reads p-codes.(only connects to ECM) and you have the 60 ohms reading on the data wires, it sounds like the ECM isn’t broadcasting. Check a wiring diagram/pinout to confirm that you are getting power and ground at all of the ECM wires that should have power and ground.
I found a loose ground on C1 from where I cut the low pressure switch out for the AC, tied it in, checked the other two connectors and everything seems to be fine. Still no fire and no obd port. I have HPT and my buddy has a scanner that reads BCM’s but I’m kind of hesitant to hook either one to it
 

Gtstorey

Goblin Guru
Hpt will only read ECM and TCM anyway.

A short to ground on a data wire is also possible if you don’t see voltage.
 

ZLCHAPO

Member
Hpt will only read ECM and TCM anyway.

A short to ground on a data wire is also possible if you don’t see voltage.
It’s a straight shot from the pin 2 on the obd port to c1 connector so I don’t think that’s the issue. I found a pin out for all of the ecm connectors and I don’t have any juice with the key on to the 5v reference pins. Not sure if it needs to be running for those to have juice or not
 

Gtstorey

Goblin Guru
Should not need to be running to power the 5v bus. Sounds more like you don't have power or ground to all of the pins to the ecm as a best guess. A bad ECM could cause these symptoms but would be rare to have one die to this extent.

You really need to get the wiring diagrams along with the pinouts. Pinouts by themselves don't tell the complete story. There used to be some free links to OEM service manuals on here.
 

ZLCHAPO

Member
Should not need to be running to power the 5v bus. Sounds more like you don't have power or ground to all of the pins to the ecm as a best guess. A bad ECM could cause these symptoms but would be rare to have one die to this extent.

You really need to get the wiring diagrams along with the pinouts. Pinouts by themselves don't tell the complete story. There used to be some free links to OEM service manuals on here.
Alright I’ll keep after it, thank you again for the help
 
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