LSJ injectors not pulsing
LSJ injectors not pulsing
Well the 4 injectors have their 12V reference off the injector fuse, but the other side of the injector circuit where it goes to pins 33, 53, 54, 55 on the PCM is not doing its job.
All 4 cylinders are bone dry
I know the injectors work I tested them and they are also within coil spec
I have fuel pressure at the rail and spark.
I have a CKP signal on both wires and my RPM gauge moves when cranking
My CMP code is disabled for now, but the sensor was aligned correctly (after 3rd time)
This all leads me to believe the PCM grounding circuit which pulses the 4 injectors is not performing, could this be caused by an anti-theft system of some sort?
car is a 2004 lsj redline
fuel system schematic for reference:
All 4 cylinders are bone dry
I know the injectors work I tested them and they are also within coil spec
I have fuel pressure at the rail and spark.
I have a CKP signal on both wires and my RPM gauge moves when cranking
My CMP code is disabled for now, but the sensor was aligned correctly (after 3rd time)
This all leads me to believe the PCM grounding circuit which pulses the 4 injectors is not performing, could this be caused by an anti-theft system of some sort?
car is a 2004 lsj redline
fuel system schematic for reference:
No it's my PCM. Not sure if it's oem 100%, I bought the car used but the PCM was stock tuned..
Also found this may be helpful:
"If the spark is clean and matching engine rpm but the injectors are not then check the signal from the Throttle Position Sensor (TPS). A failing TPS can trigger the computer’s program to activate what is called the clear flood mode. This command is activated if the TPS voltage is high. The computer in response will reduce injector pulses or even turn them off while cranking the engine. There are 2 other critical inputs that the computer needs and that is the coolant temperature and load sensor information. Both of these can be checked with a scan tool while checking TPS values. When diagnosing a possible computer failure you have to confirm that the computer is receiving “all” the information it needs to operate (good inputs). If the in going information is good, but what is coming out is bad you could be looking at a replacement computer. "
Also found this may be helpful:
"If the spark is clean and matching engine rpm but the injectors are not then check the signal from the Throttle Position Sensor (TPS). A failing TPS can trigger the computer’s program to activate what is called the clear flood mode. This command is activated if the TPS voltage is high. The computer in response will reduce injector pulses or even turn them off while cranking the engine. There are 2 other critical inputs that the computer needs and that is the coolant temperature and load sensor information. Both of these can be checked with a scan tool while checking TPS values. When diagnosing a possible computer failure you have to confirm that the computer is receiving “all” the information it needs to operate (good inputs). If the in going information is good, but what is coming out is bad you could be looking at a replacement computer. "
someone have any input on the passlock system?
Vehicle Theft Deterrent (VTD) Description
The vehicle theft deterrent system is designed in order to prevent vehicle theft by disabling the fuel injectors unless the lock cylinder is engaged by the correct mechanical key. The theft deterrent system uses the following 4 components for theft prevention:
* The lock cylinder
* The ignition switch
* The body control module (BCM)
* The powertrain control module (PCM)
When starting the engine, the PCM searches for a password from the BCM through the Class 2 serial data circuit. If the password is not recognized or not present, the PCM will disable the fuel injectors. Two modes of tamper detection are provided:
* No password received The engine will start and stall quickly. SECURITY telltale will flash on the instrument panel cluster (IPC) and then stay ON steady.
* Incorrect or disable password received (More than 3 invalid passwords are received) The engine is disabled for at least 10 minutes and the SECURITY telltale will illuminate solid on the IPC during the 10 minutes.
After the vehicle has passed theft detection, the PCM will continue normal operation.
Ignition Switch
The mechanical key and lock cylinder is located on the steering column. The main electrical switching portion of the assembly is separate from the key and lock cylinder. The VTD portion of the ignition switch is the PasslockĀ cylinder.
The PasslockĀ lock cylinder is a locking cylinder that turns a magnet past a stationary hall effect sensor. When turned to crank, the hall effect sensor is latched which applies a fixed resistance to the PasslockĀ signal data circuit. The voltage measured by the BCM on the PasslockĀ signal data circuit is the PasslockĀ data value.
Body Control Module (BCM)
The BCM compares the PasslockĀ data value to a value that it has stored in memory. If the values match the BCM sends a password via the class 2 serial data line to the PCM.
Powertrain Control Module (PCM)
When the PCM receives the correct password, the PCM enables the fuel injection system, allowing the vehicle to operate correctly. The PCM may allow the car to start and quickly stall during a failed theft condition.
If the BCM does not receive a PasslockĀ data value, the BCM will enter a short tamper mode. During this mode, the VTD system will not allow the car to operate for 4 seconds.
If the PasslockĀ data value is incorrect, the VTD system will enter the long tamper mode. In the long tamper mode, the following actions will occur:
* The THEFT SYSTEM indicator will flash.
* The fuel injectors will be shut off for approximately 10 minutes.
Although the vehicle may start, the engine will quickly stall due to a fuel cut-off.
In the event of an open in the serial data communication between the BCM and the PCM or a failure in the PasslockĀ lock cylinder, the following actions occur:
* The VTD system will become fail-enabled if the car has already passed theft for that ignition cycle (i.e. the engine is running).
* The PCM or the BCM may set diagnostic trouble codes (DTCs).
* The THEFT SYSTEM indicator will light continuously.
* The PCM will become fail-enabled for future ignition cycles.
If a failure occurs when the ignition is off, while the VTD system is not fail-enabled, the PCM will never receive a valid password, and will not allow vehicle operation by disabling the fuel injectors.
Vehicle Theft Deterrent (VTD) Description
The vehicle theft deterrent system is designed in order to prevent vehicle theft by disabling the fuel injectors unless the lock cylinder is engaged by the correct mechanical key. The theft deterrent system uses the following 4 components for theft prevention:
* The lock cylinder
* The ignition switch
* The body control module (BCM)
* The powertrain control module (PCM)
When starting the engine, the PCM searches for a password from the BCM through the Class 2 serial data circuit. If the password is not recognized or not present, the PCM will disable the fuel injectors. Two modes of tamper detection are provided:
* No password received The engine will start and stall quickly. SECURITY telltale will flash on the instrument panel cluster (IPC) and then stay ON steady.
* Incorrect or disable password received (More than 3 invalid passwords are received) The engine is disabled for at least 10 minutes and the SECURITY telltale will illuminate solid on the IPC during the 10 minutes.
After the vehicle has passed theft detection, the PCM will continue normal operation.
Ignition Switch
The mechanical key and lock cylinder is located on the steering column. The main electrical switching portion of the assembly is separate from the key and lock cylinder. The VTD portion of the ignition switch is the PasslockĀ cylinder.
The PasslockĀ lock cylinder is a locking cylinder that turns a magnet past a stationary hall effect sensor. When turned to crank, the hall effect sensor is latched which applies a fixed resistance to the PasslockĀ signal data circuit. The voltage measured by the BCM on the PasslockĀ signal data circuit is the PasslockĀ data value.
Body Control Module (BCM)
The BCM compares the PasslockĀ data value to a value that it has stored in memory. If the values match the BCM sends a password via the class 2 serial data line to the PCM.
Powertrain Control Module (PCM)
When the PCM receives the correct password, the PCM enables the fuel injection system, allowing the vehicle to operate correctly. The PCM may allow the car to start and quickly stall during a failed theft condition.
If the BCM does not receive a PasslockĀ data value, the BCM will enter a short tamper mode. During this mode, the VTD system will not allow the car to operate for 4 seconds.
If the PasslockĀ data value is incorrect, the VTD system will enter the long tamper mode. In the long tamper mode, the following actions will occur:
* The THEFT SYSTEM indicator will flash.
* The fuel injectors will be shut off for approximately 10 minutes.
Although the vehicle may start, the engine will quickly stall due to a fuel cut-off.
In the event of an open in the serial data communication between the BCM and the PCM or a failure in the PasslockĀ lock cylinder, the following actions occur:
* The VTD system will become fail-enabled if the car has already passed theft for that ignition cycle (i.e. the engine is running).
* The PCM or the BCM may set diagnostic trouble codes (DTCs).
* The THEFT SYSTEM indicator will light continuously.
* The PCM will become fail-enabled for future ignition cycles.
If a failure occurs when the ignition is off, while the VTD system is not fail-enabled, the PCM will never receive a valid password, and will not allow vehicle operation by disabling the fuel injectors.
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