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ECM X1 & X2 Plug wires cut out

Doug Rostad

Well-Known Member
Doug Rostad
Can someone please confirm these wires should be cut out for the Goblin?

ECM X1
Pin 42 Dark Green Pressure sensor signal --> Pin 1 Fuel Tank Pressure Sensor
Pin 66 Gray 5v Reference --> Pin 3 Fuel Tank Pressure Sensor
Pin 70 White Vent Solenoid Control --> Pin B Evaporative Emissions Canister Solenoid Valve

ECM X2
Pin 30 Dark Green Purge Solenoid Control --> Pin B Evaporative Emissions Canister Solenoid Valve
Pin 42 Purple & White Low Reference --> Pin 1 A/C Refrigerant Pressure Sensor
Pin 55 White 5v Reference --> Pin 1 Secondary Air Injection Pump Solenoid
Pin 64 Tan Low Reference --> Pin 3 Secondary Air Injection Pump Solenoid
 
Ross
Those all seem like logical things to remove, as they aren't used in a goblin.
I'm not sure what donor car you have, but here is some electrical diagrams:
manual for your goblin donor. downloadable 7-zip or WinRaR
 
Doug Rostad
Those all seem like logical things to remove, as they aren't used in a goblin.
I'm not sure what donor car you have, but here is some electrical diagrams:
manual for your goblin donor. downloadable 7-zip or WinRaR
Thanks !I still have a "no crank" condition. The miring harness back on the table. Those were the only few cut out at the ECM. I still have a couple at the BCM im looking for the full BCM schematic. I will look in there!
 
Doug Rostad
Ok, Another Wiring question
On the BCM Plug X1 Pins 18 & 36 circuit 5060 Dark Green Low Speed GMLAN Serial Data wires that went to the radio.... Do these need to be tied into the other Dark Green Low Speed GMLAN Serial Data wires ?
 
Doug Rostad
The 2009 Cobalt 2.2L has a manual transmission.
What would the BCM Plug X1 Pin 33 Dark green and white wire" A/T Shift Lock Control Solenoid Supply Voltage" Output for auto shift display.... be connecting to on my car ?
 
Ross
The A/T is for automatic transmission... which has a shift lock.
Here is the connector pinout. It mentions the MN5 (Automatic Transmission 4 Speed) and MXO is a general code for an automatic transmission.
You have the 5 speed manual transmission, so no need to supply voltage to that solenoid.
46736
 
Doug Rostad
The A/T is for automatic transmission... which has a shift lock.
Here is the connector pinout. It mentions the MN5 (Automatic Transmission 4 Speed) and MXO is a general code for an automatic transmission.
You have the 5 speed manual transmission, so no need to supply voltage to that solenoid.
View attachment 46736
Thanks Ross ! I'm grasping at straws ,trying to find something I may have done wrong, or any discrepancies , I just can't find anything that is keeping it from cranking.
I will have the harness back in the car by 6pm tonight, to continue checking voltages. I'm thinking about starting at the 5v at the clutch pedal. And go from there.
 
Ross
It might just be the connectors. They are designed for a limited use, and can get damaged (loose connection) or get dirt in them, and prevent electricity from flowing. So even if the harness is correctly modified, you can get issues. You can isolate the issue when the harness is installed, and you use an electrical meter to find any problems.

Back in February you were chasing down a communication issue. Is that where you are today? Bring me up to speed on where your goblin is at.
In March you were blowing fuses, after buying many ECM and BCMs.
 
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Doug Rostad
It might just be the connectors. They are designed for a limited use, and can get damaged (loose connection) or get dirt in them, and prevent electricity from flowing. So even if the harness is correctly modified, you can get issues. You can isolate the issue when the harness is installed, and you use an electrical meter to find any problems.

Back in February you were chasing down a communication issue. Is that where you are today? Bring me up to speed on where your goblin is at.
In March you were blowing fuses, after buying many ECM and BCMs.
I figured out the data ,tan and tan and brown wires changed the ECU then I started to have 61.4 ohms at the DLC. AND MY 5V ,, , 2.48 on one and 2.52 on the other. no more blown fuses either, oh also the throttle started to respond..
 
Ross
Congrats on getting the high speed LAN to the correct resistance.
Your two 5 volt circuits are both under 3V?
Weird that both circuits have an issue. Where did you measure the voltage at?
Something is dragging down the voltage... probably related to why it isn't starting.
 
Doug Rostad
Congrats on getting the high speed LAN to the correct resistance.
Your two 5 volt circuits are both under 3V?
Weird that both circuits have an issue. Where did you measure the voltage at?
Something is dragging down the voltage... probably related to why it isn't starting.
I mean the High speed voltage from the OBDII pins 5 and 6 and 5 and 14
 
Doug Rostad
I could not get the passckey light to go off,, so I bought a steering column with a key , cylinder and module. Now the passkey light is now off after being able to program the key.
 
Ross
Well that is progress! Does the engine start or do we have new symptoms now?
OBDii pins 6 and 14 are the GM high speed LAN wires, which are bouncing between 1.5 and 3.5 volts, so the voltage measurements you got were normal.
 
Doug Rostad
Well that is progress! Does the engine start or do we have new symptoms now?
OBDii pins 6 and 14 are the GM high speed LAN wires, which are bouncing between 1.5 and 3.5 volts, so the voltage measurements you got were normal.
So, Sunday I went to the garage to check voltages going from the key switch to the BCM (where I hear the relay clicking as I turn the key) when I tried to cycle through my info buttons oil / tire pressure/ water temp... they stopped working" they worked Saturday. Then I checked throttle response,,,, nothing,,, it worked Saturday. Being completely defeated, I turned and walked away.
Last night I bought a complete body wiring harness $213.00 today I bought a NOS dash wiring harness $98.63 both part numbers I got from Chevrolet , per my VIN number. I will be removing my engine wiring harness , lay that out and check for any discrepancies from after removing the A/C and smog pump connectors from the harness.
 
G
This is not that unusual. The individual wire connectors get looser the more they are messed with. The large connectors aren't really designed to be taken loose multiple times and if you start having issues where you are trouble shooting them a lot, the worse they get. You also have to be careful when using a voltmeter to check things and not spread the connectors open even more.

The ECM's individual wire connectors can be take out and tightened but it's a little tedious. The small BCM/ECM connectors are really hard to do much with. I've added a hold down to one of my BCM connectors to keep it from moving, even though the OEM lock is still there.

At some point, you might want to invest in the VCX Nano so you can get a better idea what isn't working correctly.
 
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