Ark's City Goblin #187 (2008 SS/TC donor)

benjy

benjy

Well-Known Member
Amazing. Thanks for taking us along for the journey. I was out of cell/wifi coverage for the weekend, and I was really looking forward to the developments, this did not disappoint :cool:
 
Ark :D

Ark :D

Goblin Guru
So after an evening of celebration via a bottle of wine, I'm back to trying to figure out the starting issue with this car.

I managed to get the remainder of the screw out of my original clutch position sensor, so now the original is all mounted back up. It's still not the original brake position sensor because it's gone. That being said, no crank. Does the brake sensor need to be calibrated for the car to start also?
 
Y

Yustas

Active Member
Non calibrated brake affects stop lights behavior but not crank. I was able to start the engine with brake pedal position sensor reporting out of range value.
 
Ark :D

Ark :D

Goblin Guru
Ok. I'll keep looking for a possible fix.

On a positive note, I've all but verified that it's just my scanner than won't connect via OBDII. I plugged in bradr's ABS Eliminator and it worked like a charm, so the communication is definitely there.
 
Mayor West

Mayor West

Goblin Guru
I have to do the same to mine (before disassembly) and I'm excited to be in the same boat as you when I am at that point.

Mines due to the clutch sensor.
 
B

Briann1177

Goblin Guru
Check your clutch sensor wiring. The tan and gray wires have a junction that ran to other emissions components that were deleted. If you weren't paying attention you might have cut too much out.

20200623_203158.jpg
 
Ark :D

Ark :D

Goblin Guru
It's a little late on a work night to dive into the wiring too deeply, but I did check voltages. With ignition ON:

Tan: no voltage
Light Green: anywhere from 1v to 4.5v or so, based on the potentiometer's position
Gray: constant 5v

Does that sound right?
 
B

Briann1177

Goblin Guru
That sounds right. As long as the sensor is in the correct position, there shouldn't be an issue. The engine fires right up when you jumped your starter motor so that kind of tells me there is something wrong with the crank circuitry.

1. Make sure you have 12V at the starter motor.
2. Make sure your purple wire is hooked back up to the starter motor.
3. Swap your crank relay out. Make sure you look at the CRNK relay and not the RUN/CRNK relay. Your instrument panel is working so it's not the RUN/CRNK relay causing problems.
4. Check your connections, grounds, etc. Especially check your engine-to-frame ground connection.
5. Check for 12V on the purple wire while you're cranking.
 
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Ark :D

Ark :D

Goblin Guru
More tomorrow, but I'll close tonight with;

  1. The 30A CRNK fuse is good. First I've dealt with this type of fuse, so I figured I would re-check it.
  2. The CRNK relay should be good. I swapped it with both the REAR DEFOG and FAN1 relays just to make sure I didnt have TWO bad relays.
  3. When I remove the CRNK relay and jump it with the ignition on, it fires right up, so I am undoubtedly getting 12v to the starter solenoid connector.
This pretty much has to be an issue with the car's logic. I will see what I can find out tomorrow.
 
Ross

Ross

Goblin Guru
I'm going to pay close attention to this as I am having this same issue with my 2006 SC LSJ. Sometimes the engine won't crank with the key. I have run a wire from the solenoid that I can put in the aux power jack (cigarette lighter for us old timers) and it will crank the starter on my car... just hate having to dig out a wire, and steal my own car. Since my dash gauges are intermittent, I am thinking it is a data issue with my car.
 
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Briann1177

Goblin Guru
I read through my service manual on how cranking occurs. When you turn the key to crank the BCM sends a discrete signal to the ECM over the data network. The ECM monitors for the correct position of the clutch sensor. The ECM also checks for any engine codes that will prevent a good start. If all that is good, then it activates the crank circuitry.

As far as I can tell from your previous video, the dash lights go off when you turn the key to crank. That tells me at least the BCM is getting the message. The next hop is the ECM. You have already verified your green and tan wiring so i wouldn't think that would be an issue.

That really only leaves your clutch sensor and crank circuits. Im far from an expert like bradr, but thats what I'm gathering based on what I'm reading. Im sure there is bit more to it than that.
 
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bradr

Well-Known Member
Ark :D said:
Ok. I'll keep looking for a possible fix.

On a positive note, I've all but verified that it's just my scanner than won't connect via OBDII. I plugged in bradr's ABS Eliminator and it worked like a charm, so the communication is definitely there.
Click to expand...
This only tells you that you have communication up to the BCM. The ABS eliminator does not communicate with the PCM. If your OBDII scanner will not communicate with the PCM, you likely still have an issue.
  1. Did the "Power Steering" Message get resolved?
  2. Are you seeing an accurate coolant temperature in the instrument cluster?
 
Ark :D

Ark :D

Goblin Guru
bradr said:
This only tells you that you have communication up to the BCM. The ABS eliminator does not communicate with the PCM. If your OBDII scanner will not communicate with the PCM, you likely still have an issue.
  1. Did the "Power Steering" Message get resolved?
  2. Are you seeing an accurate coolant temperature in the instrument cluster?
Click to expand...
Funny you should say that, I was actually thinking about that as I was trying to go to sleep last night.

  1. Yes - no more Power Steering message on the information center.
  2. I do not know. I have not run it long enough to see. I have the rear up on jack stands so I've been a little leery of running it that way. I still have to fully fill and burp the coolant system, also.
 
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bradr

Well-Known Member
Ark :D said:
I do not know. I have not run it long enough to see.
Click to expand...
No need for the engine to be running. Does the coolant temperature show something close to room temperature when the ignition is on, engine off?

The coolant temp sensor is wired to the PCM. The temperature is communicated over CANbus to the BCM, then the BCM sends it to the cluster on the single wire CANbus. The display will read "-40F" for the temp if the PCM is not connected.

EDIT: Updated behavior when PCM not connected.
 
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Ark :D

Ark :D

Goblin Guru
bradr said:
No need for the engine to be running. Does the coolant temperature show something close to room temperature when the ignition is on, engine off?

The coolant temp sensor is wired to the PCM. The temperature is communicated over CANbus to the BCM, then the BCM sends it to the cluster on the single wire CANbus. I think that the display will read "--" for the temp if the PCM is not connected. I will need to verify this on my car when I get a chance.
Click to expand...
In that case, I can check this out pretty easily. One thing though; would I have to cycle the "Info" button to see coolant temp displayed?
 
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