cranks but won't start?

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If it stays running when you add fuel, then everything signal wise is there, it's like its not firing the injectors when the ignition switch is in the crank position .
I would check at the injector connectors making sure they are getting pulsed , noid lights are handy for that . Or you can pull the injectors and rail to verify spray pattern in the cranking position.
Sounds very plausible it has no injector pulse in the crank position and does when you release the ignition switch to the run position.
 
Another thing, since your voltmeter is broken, are you relying on the gauge to tell you that its not charging? There may be a ground under the dash that needs hooked up for the cluster, and could be causing other issues too. Just another thing to check.
 
blown71duster said:
If it stays running when you add fuel, then everything signal wise is there, it's like its not firing the injectors when the ignition switch is in the crank position .
I would check at the injector connectors making sure they are getting pulsed , noid lights are handy for that . Or you can pull the injectors and rail to verify spray pattern in the cranking position.
Sounds very plausible it has no injector pulse in the crank position and does when you release the ignition switch to the run position.
Click to expand...

Blown71Duster just noticed you're in Troy, I live in your neck of the woods, Pleasant Hill.
 
Picked up a multimeter today and its not charging. I work a 24 hour shift tomorrow so i won't get anything accomplised tomorrow. Thursday i will return the fuel pressure tester and see if they have the noid kit. Thanks for all of the help and suggestions. Hopefully we get to the bottom of this. The truck is my daily driver. Im having to ride my bike to work and its supposed to finally start getting cold here!!
 
Say tomorrow when I check it and the injectors aren't firing when it's cranking, what does that mean?
 
Here is OEM service manual info :

ENGINE START-UP MODE

This is an Open Loop mode. The following actions occur when the starter motor is engaged.

The PCM receives inputs from:
•Battery voltage
•Engine coolant temperature sensor
•Crankshaft position sensor
•Intake manifold air temperature sensor
•Manifold absolute pressure (MAP) sensor
•Throttle position sensor (TPS)
•Starter motor relay
•Camshaft position sensor signal

The PCM monitors the crankshaft position sensor. If the PCM does not receive a crankshaft position sensor signal within 3 seconds of cranking the engine, it will shut down the fuel injection system.

The fuel pump is activated by the PCM through the fuel pump relay.

Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.

The PCM determines the proper ignition timing according to input received from the crankshaft position sensor
----------------------------------------------
This is a very unusual problem , usually the most common thing is to lose spark and the injection signal together and it usually is due to a loss of crank signal , very common problem on these.
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If you are loosing injector pulse with your ignition switch in crank position I would be checking power to the pcm with the ignition switch held in that position. There is power that should be hot in crank and run position. I would check both the powers and grounds here at the pcm .

Best way to check powers and grounds at the computer is to use a sealed beam headlamp ,it puts that circuit under load.
Get you a headlight with a couple of leads, ground one lead to the battery negative and use a straight pin or paper clip on the other lead and insert it into the pcm connector on your powers ( connector 1 pin 2 and pin 22 are powers ) look for a nice brightly lit headlamp and make sure it has power in run and crank on pin 2 cavity.
Reverse to check your grounds , one lead on the positive battery and the other checking the connector pins 31 and 32 . These are the two grounds ,once again looking for a brightly lit headlamp which tells you its a good ground under load.
These powers and grounds have to be good for everything to work.
The pcm controls the charging system , so the grounds have to be right to work .
 

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Had a few minutes before i have to help out at the kids school. I plugged in my buddies obdII scanner and my port won't even power it up? Where does that put us? Something is not getting power?
 
I know this is gonna sound elementary, but have you checked your fuses? I know the wiring from the data link connector comes from the PDC, just not sure if it's actually powered there or at the PCM. There are two grounds on the data link connector, one regular ground and one isolated ground. Make sure that the grounds for the PDC are connected.
 
Need to check power and grounds at DLC:

DATA LINK CONNECTOR - BLACK 16 WAY

CAV CIRCUIT FUNCTION
1 - -
2 - -
3 D1 20VT/BR CCD BUS(+)
4 Z33 16BK/RD GROUND
5 Z12 18BK/RD GROUND
6 D20 20VT/WT SCI RECEIVE
7 D21 20PK/DB SCI TRANSMIT
8 - -
9 - -
10 - -
11 D2 20WTR/BK CCD BUS (-)
12 - -
13 - -
14 D22 20LG SCI RECEIVE
15 - -
16 M1 20PK FUSED B(+)
 

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Looks like the junction block fuse 12 among others gets its power from a 40 amp fuse in the power distribution center
 

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So fuse 12 was blown, couldn't tell under the cover on it (Thanks guys). That gave me power to the data link connector. I cranked it and it threw a p1389 code.
 
UH OH - P1389 No Auto Shutdown (ASD) Relay Output Voltage At PCM

On the bright side - You're getting closer! Check the relay in the PDC.
 
As 68coupe suggested check the relay, switch with another known good. If that doesn't fix then you need to dig further. Makes sure the power and grounds are good to the pcm first!!!

OEM direct info on that code:
Symptom:
P1389-NO ASD RELAY OUTPUT VOLTAGE AT PCM
When Monitored and Set Condition:
P1389-NO ASD RELAY OUTPUT VOLTAGE AT PCM
When Monitored: With ignition key on, battery voltage above 10.4 volts, and engine RPM
greater than 400.
Set Condition: No voltage sensed at the PCM when the ASD relay is energized.
POSSIBLE CAUSES
WIRING HARNESS INTERMITTENT PROBLEM
ASD RELAY OUTPUT CIRCUIT OPEN
FUSED B+ CIRCUIT OPEN
ASD RELAY
PCM

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So the pcm is controlling the asd relay by sending a ground to energize it and at the same time it is looking for an input from the asd coming in on connector 3- pin12 . You wil want to make sure the two powers coming into the relay are good . Also here are some tests for that code:
Tests/Procedures:

1. Check the power at pin 3 of the Grey connector at the Powertrain Control Module (PCM) key on engine off, it should be system voltage.

2. Crank the engine over, the voltage should drop to about 1 volt. If it doesn't, check the Crank Position Sensor (CKP) and Cam Position Sensor (CMP) signals. If it does, check the input voltage on the Dark Green/Orange wire at pin 12 of the Grey connecter when cranking, it should be battery voltage.
--------

Tests/Procedures:

1. Remove the Automatic Shut Down (ASD) relay and jumper terminals 30 and 87.

2. Check for B+ on the Dark Green/Orange wire at pin 12 in the gray Powertrain Control Module (PCM) connector and on the White/Dark Blue wire at pin 25 in the gray PCM connector.

3. If not B+ on the White/Dark Blue wire, check the wire for a short to ground. If the wire is shorted, it may have damaged the internal circuit in the PCM. Internally, the Dark Green/Orange wire and the White/Dark Blue wire are connected.

Tech Tips:

Do not replace the PCM prior to finding the cause of the failure.
 

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Alright I have a ghost plug by the PCM. My main power wire that is supposed to go to hole 12 goes to this plug first, but i have no idea what goes here and i dont remember pulling anything out?



 
I believe that is your C105 plug .You are saying that the DG/OR from cavity 12 of connector 3 is going to this ? If so that is connector labeled C105

I will give you some things the male side wires out of the plug are feeding , so maybe you can trace them and find the male plug .
WT/OR wire is going from the male plug of the c105 to abs controller
Wire from the ac low pressure switch is going to the male plug , diagram is vague on that color
Both of your oxygen sensor wires DG/RD will feed to the missing connector also
Wt/DB from your generator is going to the plug-that would explain your no charge

I will show the wiring diagram for the low side ac switch and couple of pics of the connectors. Hopefully you can trace some of the wires above to the male connector -Good luck !!
 

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Id go back to the car and double check it was mounted to something within reach of what ever is further back up the wiring. Generally plugs on modern vehicles are all different shaped slightly so you cant mismatch. Guessing you left something on or in th car.
 
It's alive!!! As of 9:30 last night:cheers:. That plug was my issue. I never had any power at pin 12. Didn't have any continuity through the wire feeding pin 12 from the ASD. After pulling the loom apart and chasing wires I realized the power went to my mystery (C105) plug. Turns out the female side of that plug was stuffed up under the frame rail and out of sight. I swear I double and quadruple checked all that as did my buddy, but it was just in the perfect out of sight spot. Thank you everyone for taking the time out to help me sort this out. I was just about convinced the PCM was bad. THANK YOU THANK YOU..Now on to wiring my head and tail lights. Here we go again.
 
Where is the plug coming out of the harness and I will look at mine. I just took a quick look at mine and didn't see a plug configured like that.

Nevermind...... Glad you got it fixed!
 
The male portion is part of the front harness with connector 3 that goes to the PCM. That harness has the fan and headlights. The female portion is part of the harness with connector 1 and 2.

I feel this entire issue was a blessing, I have now learned a lot of the ins and outs of this set up which I'm sure will help myself or someone else along the way.
 
Just as a final note, my harness doesn't have the same plug. C105 on mine goes to the foglights. Good Luck and post some pictures of the truck. Sweet!
 
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