P1219 CID stuck low
- Thread starter onebad7.3
- Start date
cowboy_dan
Member
There are two main communication lines between the PCM and the IDM for running the injectors. One is the CID and I don't remember the other.
Basically the other one will pulse up and down in a sorta-square wave to signal when each cylinder is supposed to inject.
The CID stands for Cylinder ID. The CID pulses up for four of the other signal's pulses, and down for the other four to indicate which set of injectors is supposed to be injecting. If the CID is stuck high or low, the IDM will never know which injector to start with. Think of the CID signal as being a synchronizing signal to make the other signal match the engine position.
In your case, it means the voltage is too low, and it is not coming high enough to be used.
Without having internal diagrams of the PCM and the IDM, this could mean a bad connection (corrosion, pins pushed back it he connector body, loose connector, etc..) or a damaged wire (think shorted to ground).
Basically the other one will pulse up and down in a sorta-square wave to signal when each cylinder is supposed to inject.
The CID stands for Cylinder ID. The CID pulses up for four of the other signal's pulses, and down for the other four to indicate which set of injectors is supposed to be injecting. If the CID is stuck high or low, the IDM will never know which injector to start with. Think of the CID signal as being a synchronizing signal to make the other signal match the engine position.
In your case, it means the voltage is too low, and it is not coming high enough to be used.
Without having internal diagrams of the PCM and the IDM, this could mean a bad connection (corrosion, pins pushed back it he connector body, loose connector, etc..) or a damaged wire (think shorted to ground).
JD3020
Active member
Yes. Mine got full of water and what day it shorted out and took out one bank of injectors. Had to drive about 15 miles to get home on 4 cylinders.
Tom S
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Can you hear any water in there if you shake it?
No,
I checked all the wiring out and everything looks like new. I thought maybe it was a wire shorting out, I didn't find anything, but one could hang himself with all the wires in there.
PCA serial buss
FDCS & CID
Fuel Delivery Command Signal (blue)
Cylinder Identification (red)
CID goes high to signal the start of revolution one and remains high for the duration of the first revolution, then it goes low for the duration of the second revolution. 75uS (microseconds) after CID goes high, the first FDCS signal arrives, signaling that it is time to turn on injector #1 and it is kept on until FDCS goes low. The next FDCS signal means it is time to turn on injector #2, and so on. The engine firing order is 1-2-7-3-4-5-6-8 with 1-2-7-3 fired during the first rotation and 4-5-6-8 fired during the second rotation, so 1-2-7-3 are fired while CID is high, and 4-5-6-8 while it is low. At some point after the end of firing injector #3, depending on injector pulse width and RPM, CID goes low. 75uS after it goes low, the signal for injector # 4 arrives, followed by 5-6-8. Some time after #8 ends, CID will go high again and the cycle is repeated.
Fuel Delivery Command Signal (blue)
Cylinder Identification (red)
CID goes high to signal the start of revolution one and remains high for the duration of the first revolution, then it goes low for the duration of the second revolution. 75uS (microseconds) after CID goes high, the first FDCS signal arrives, signaling that it is time to turn on injector #1 and it is kept on until FDCS goes low. The next FDCS signal means it is time to turn on injector #2, and so on. The engine firing order is 1-2-7-3-4-5-6-8 with 1-2-7-3 fired during the first rotation and 4-5-6-8 fired during the second rotation, so 1-2-7-3 are fired while CID is high, and 4-5-6-8 while it is low. At some point after the end of firing injector #3, depending on injector pulse width and RPM, CID goes low. 75uS after it goes low, the signal for injector # 4 arrives, followed by 5-6-8. Some time after #8 ends, CID will go high again and the cycle is repeated.
cowboy_dan
Member
FDCS & CID
Fuel Delivery Command Signal (blue)
Cylinder Identification (red)
CID goes high to signal the start of revolution one and remains high for the duration of the first revolution, then it goes low for the duration of the second revolution. 75uS (microseconds) after CID goes high, the first FDCS signal arrives, signaling that it is time to turn on injector #1 and it is kept on until FDCS goes low. The next FDCS signal means it is time to turn on injector #2, and so on. The engine firing order is 1-2-7-3-4-5-6-8 with 1-2-7-3 fired during the first rotation and 4-5-6-8 fired during the second rotation, so 1-2-7-3 are fired while CID is high, and 4-5-6-8 while it is low. At some point after the end of firing injector #3, depending on injector pulse width and RPM, CID goes low. 75uS after it goes low, the signal for injector # 4 arrives, followed by 5-6-8. Some time after #8 ends, CID will go high again and the cycle is repeated.
:whs:
I was close, just missing a few details. lol
