Ignition problem - serial communication link

In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM (Theft Deterrent Module). These 3 parts are in CONSTANT communication. If the key is in the ignition, then these parts are sending signals to each other.
The security light illuminates when that signal gets broken, or not seen at all. When the communication breaks, the car misinterprets this as an attempt at theft and goes into antitheft mode. (like it thinks it's being hot wired) The car shuts down because it is not getting that signal from YOUR specific key. This is why the security light turns on and shuts down your vehicle. It will either turn off the starter, or the fuel injectors. The vehicle may run for 2-3 seconds before shutting down. This link explains it pretty well.
http://www.diy-gm-security.com/




Do It Yourself GM Security bypass

Well now that some problem ! The problem with going to the parts store to have codes checked is they only check PCM - engine computer codes . Your vehicle has more then just the PCM/ECM
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The instrument panel cluster (IPC)

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The engine/powertrain control module (ECM/PCM)

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The electronic brake control module (EBCM)

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The HVAC control module

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The radio

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The dash integration module (DIM)

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The rear integration module (RIM)

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SP303

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The inflatable restraint sensing and diagnostic module (SDM
All These modules share information on the class 2 serial data bus any one of these modules could have a lose or bad ground causing these problems !
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Scan tool power battery positive voltage at terminal 16.

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Scan tool power ground at terminal 4.

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Common signal ground at terminal 5.

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Class 2 serial data at terminal 2.

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Keyword serial data at terminal 7, w/TR7.

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High Speed GMLAN (+) serial data at terminal 6, w/LY7 or LP1.

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High Speed GMLAN (-) serial data at terminal 14, w/LY7 or LP1.

The serial data circuits are the means by which the control modules on the vehicle communicate with each other and the scan tool. There are 3 different types of protocols on this vehicle.
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The class 2 serial data

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The keyword 2000 serial data

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The high speed GMLAN serial data

The scan tool will power up with the ignition off. Some modules however, will not communicate unless the ignition is on and the power mode master (PMM) module sends the appropriate power mode message. Refer to Body Control System Description and Operation for operation of the PMM.
Class 2 Serial Data
The data link connector (DLC) allows a scan tool to communicate with the class 2 serial data line. This serial data line is the means by which the microprocessor-controlled modules in the vehicle communicate with each other. Once the scan tool is connected to the class 2 serial data line through the DLC, the scan tool can be used to monitor each module for diagnostic purposes and to check for diagnostic trouble codes (DTCs). Class 2 serial data is transmitted on a single wire at an average of 10.4 kbps. This value is an average, class 2 uses a variable pulse width modulation to carry data and depending on the message it may operate faster or slower. The bus will float at a nominal 7.0 volts during normal operation. Each module can pull this lower during the transmission. The bus is not at battery positive voltage or ground potential during normal operation. When the ignition switch is in RUN, each module communicating on the class 2 serial data line sends a state of health (SOH) message every 2 seconds to ensure that the module is operating properly. When a module stops communicating on the class 2 serial data line, for example if the module loses power or ground, the SOH message it normally sends on the data line every 2 seconds disappears. Other modules on the class 2 serial data line, which expect to receive that SOH message, detect its absence; those modules in turn set an internal DTC associated with the loss of SOH of the non-communicating module. The DTC is unique to the module which is not communicating, for example, when the inflatable restraint sensing and diagnostic module (SDM) SOH message disappears, several modules set DTC U1088. Note that a loss of serial data DTC does not normally represent a failure of the module that set it.
You need to have all the modules on the vehicle checked an you need to take your vehicle to a qualified repair shop . You blame the PCM/ECM , I don't think so , sounds like a bad ground . Windows an locks not working are not part of the ECM/PCM . There are modules inside the doors.
Each door lock actuator is powered and controlled by the door module mounted in the individual door, but the rear integration module (RIM), which is the master control for the door lock system, determines when the lock functions are permitted. The RIM receives and examines lock function requests from the individual door modules, or from the remote function actuator (RFA) via the class 2 serial data circuit. The RIM also examines the transmission shift selector position and the ignition switch position information available over the class 2 serial data circuits. If the RIM determines that all conditions are correct for a lock or unlock function to be permitted, it sends a class 2 message back to the individual door modules commanding them to perform the lock or unlock function requested.
Your vehicle also has
Electronic Park Lock Description and Operation
If the vehicle is equipped with automatic transmission and a floor mounted console gear shift, it has an electronic park lock system (EPL). The EPL system purpose is to prevent the ignition key from being turned to the OFF position when the transmission is in any position other than PARK and the vehicle may still be moving. The EPL system consists of an ignition lock cylinder solenoid, and a park position switch that is located in the A/T shift lock control switch. The ignition lock cylinder solenoid contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the Park position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column
Fail-safe Operation
Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the power mode master (PMM) fail to send a power mode message. The fail-safe plan covers those modules using exclusively serial data control of power mode as well as those modules with discrete ignition signal inputs.
Serial Data Messages
The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid PMM message until they can check for the engine run flag status on the serial data circuits. If the PMM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running, the modules fail-safe to RUN. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.
Discrete Ignition Signals Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

With all of the electrical problems your having , your best bet would be to take it to a ASE certified repair shop ! Because the first place to start is hooking a professional grade scan tool to see if all the modules on the vehicle are communicating with the scan tool an each other ! I don't know the existent of your knowledge of your vehicle ! Your vehicle has at lest ten computers onboard an they all communicate on a serial data communication network , Class2 The data link connector (DLC) allows a scan tool to communicate with the class 2 serial data line. This serial data line is the means by which the microprocessor-controlled modules in the vehicle communicate with each other. Once the scan tool is connected to the class 2 serial data line through the DLC, the scan tool can be used to monitor each module for diagnostic purposes and to check for diagnostic trouble codes (DTCs). Class 2 serial data is transmitted on a single wire at an average of 10.4 kbps. This value is an average, class 2 uses a variable pulse width modulation to carry data and depending on the message it may operate faster or slower. The bus will float at a nominal 7.0 volts during normal operation. Each module can pull this lower during the transmission. The bus is not at battery positive voltage or ground potential during normal operation. When the ignition switch is in RUN, each module communicating on the class 2 serial data line sends a state of health (SOH) message every 2 seconds to ensure that the module is operating properly. When a module stops communicating on the class 2 serial data line, for example if the module loses power or ground, the SOH message it normally sends on the data line every 2 seconds disappears. Other modules on the class 2 serial data line, which expect to receive that SOH message, detect its absence; those modules in turn set an internal DTC associated with the loss of SOH of the non-communicating module. The DTC is unique to the module which is not communicating, for example, when the inflatable restraint sensing and diagnostic module (SDM) SOH message disappears, several modules set DTC U1088. Note that a loss of serial data DTC does not normally represent a failure of the module that set it.
. The ignition on you caddy has a safety system known as
Electronic Park Lock (EPL)/Ignition Lock Cylinder Control Actuator for floor shift or
Linear Shift Assembly: If the vehicle is equipped with a column mounted gear shift, it has a linear shift assembly on the steering column. The linear shift assembly has a cable that runs from the linear shift assembly to the ignition lock cylinder case. The purpose of this cable is to prevent the ignition key from being turned to the OFF position when the transmission is in gear and the vehicle may still be moving. The linear shift assembly cable contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column.
On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the dash integration module (DIM). The PMM receives 2 signals from the ignition switch.
To determine the correct power mode the PMM uses the following circuits
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Accessory voltage

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Run/Crank voltage

Did you change the lock cylinder ? You need to put the passlock?"¢ sensor out of your old steering column into the replacement one. Is the security light lit in the instrument cluster ?
The design of the passlock?"¢ system is to prevent the vehicle operation if the proper ignition key is not used in order to start the vehicle. The mechanical key, in normal operation, will turn the ignition lock cylinder. The passlock?"¢ sensor monitoring the position of the lock cylinder will relay the passlock?"¢ data to the body control module (BCM). The BCM will determine the validity of the passlock?"¢ data. The BCM will send a password to the vehicle/powertrain control module (VCM/PCM). When the VCM/PCM receives the correct password the VCM/PCM allows the fuel injectors to operate normally. The passlock?"¢ system requires the VCM/PCM and the BCM to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line CKT 1807. For an explanation of the class 2 serial data operation refer to Data Link Communications Circuit Description in Data Link Communications

For the anti-theft system in your S-10 , no key relearn is needed . No chip (transponder) in the key ! Has a sensor that is part of the lock cylinder housing , and a magnet that is part of the lock cylinder ! When you turn the key the magnet passes the sensor creating a signal that is sent to the BCM - body control module ! The BCM will send a password to the vehicle/powertrain control module (VCM/PCM). When the VCM/PCM receives the correct password the VCM/PCM allows the fuel injectors to operate normally. The passlock™ system requires the VCM/PCM and the BCM to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line CKT 1807. For an explanation of the class 2 serial data operation refer to Data Link Communications Circuit Description in Data Link .
Is the security light lit ?
Conditions
Use this procedure after replacing:
• Passlock™ Sensor
• BCM
• VCM
• PCM

10 Minute Re-Learn Procedure
Tools Required
• Tech 2
• Techline terminal with current SPS (Service Programming System) software
Connect the Tech 2 to the vehicle.
Select "Request Information" under "Service Programming".
Disconnect the Tech 2 from the vehicle and connect it to a techline terminal.
On the techline terminal, select "Theft Module Re-Learn" under "Service Programming".
Disconnect the Tech 2 from the techline terminal and connect it to the vehicle.
Turn ON the ignition, with the engine OFF.
Select "VTD Re-Learn" under "Service Programming".
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF (the vehicle is now ready to relearn the Passlock™ Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK).
Turn OFF the ignition, and wait 5 seconds.
Start the engine (the vehicle has now learned the password).
With the Tech 2 (scan tool), clear any DTCs.

your best bet , take it to a GM dealer

Without the proper testing equipment an knowledge ( factory service info. ) You have no idea what's up . an don't have a chance of fixing this . Checking for DTC'S - diagnostic trouble codes is always the first step . Take's a professional type scan tool to read these codes. Serial data info from module incharge to PCM/ECM ,enable or disable fuel and or starter operation . Sends coded messages Your best bet , take it to a qualified repair shop . That white component is the ignition switch .
The design of the passlock™ system is to prevent the vehicle operation if the proper ignition key is not used in order to start the vehicle. The mechanical key, in normal operation, will turn the passlock™ lock cylinder. The passlock™ sensor will relay the passlock™ data to the body control module (BCM). The BCM will determine the validity of the passlock™ data. The BCM will send a code password to the vehicle/powertrain control module (VCM/PCM). When the VCM/PCM receives the correct code the VCM/PCM allows the fuel injectors to operate normally. The passlock™ system requires the VCM/PCM and the BCM to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line CKT 1807. For an explanation of the class 2 serial data operation refer to Data Link Communications Circuit Description in Wiring Systems

The SECURITY light is a common problem on GM cars. The key is not just a key, it also communicates with the ignition/lock cylinder, and then to the TDM (theft deterrent module) also known as the computer. When these parts dont communcate properly, the car thinks its being stolen and turns off the starter. The hard part is finding out which part is failing. Mechanics can use this to their advantage and change everything, running up a large bill. I have found that bypassing the system is the most cost effective method and you also never have to worry about the problem EVER again. Ive bypassed dozens of GM vehicles, and never had any issues after that. Here is a link that explains the problem and offers some solutions.
http://vatspasslockpasskeysecurityhelp.yolasite.com/

Monte Carlos effected by Vats or Passlock security Failure that can be fixed by bypassing
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2005 Good luck, hope this helps. Any questions, please comment back.

U1064 - Loss of Communications with DIM (Dash Integration Module)
Here is some TSB

Refer to Data Link Connector (DLC) Schematics

Circuit Description
The class 2 serial data line communicates information between modules. Each module connected to the serial data line is assigned a recognition code, or address. This code is used in order to identify which modules are communicating. Modules communicate with each other by periodically sending state of health (SOH) messages. When the ignition switch is in RUN, each module communicating on the serial data line sends a SOH message every 2 seconds. This ensures that the system is operating properly. When the dash integration module (DIM) stops communicating on the class 2 serial data line, the SOH that is normally sent on the serial data line every 2 seconds disappears. The module, which expects to receive that message, detects the absence of the message. The module in turn sets DTC U1064 associated with the loss of SOH of the DIM.

Conditions for Setting the DTC
The module does not receive a state of health (SOH) message back from the DIM. The module retries the request 3 times, and then sets DTC U1064.

This DTC only sets if U1300 or U1301 is not current.
Action Taken When the DTC Sets
DTC U1064 is stored in the module.

The module uses the default values for the initialization data. This DTC does not cause driver warning message to appear.

Conditions for Clearing the DTC
This DTC clears (status changes from current to history) under any of the following conditions:
The module detects a state of health message from the DIM.
At each ignition cycle.
A history DTC clears after 50 consecutive ignition cycles if the conditions for setting the DTC are no longer present.
Current and history DTCs may be cleared using a scan tool.

Diagnostic Aids
DTC U1064 does not normally represent a failure within the module.
When loss of class 2 serial data communication DTCs (DTCs with the letter U as the prefix) are stored as history DTCs, know all possible serial data DTCs set in each module before diagnosing the serial data line.

If U1064 is stored in the module memory, inspect for the same DTC stored in other modules capable of storing this DTC.
If the DTC is a history DTC, the problem may be intermittent.

Test Description: The numbers below refer to the step numbers on the diagnostic table:

U1064 is the result of loss of communication with the dash integration module (DIM). Note that other modules on the class 2 serial data line may also set U1064 if the DIM is not communicating with the serial data line.

Clear all DTCs after the repair procedure is complete.
Step
Action
Value(s)
Yes
No

1
Did you perform the Data Link Communications Diagnostic System Check?
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Go to Step 2
Go to Diagnostic System Check - Data Link Communications

2
Use a scan tool in order to attempt the establish communication with the dash integration module (DIM).

Does the scan tool communicate with the DIM?
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Go to Step 3
Go to Diagnostic System Check - Body Control System in Body Control System.

3
Inspect and repair the class 2 serial data line CKT 1807 (PPL) for intermittent connections. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Is the repair complete?
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Go to Step 4
--

4
Turn off the ignition switch.
Reconnect or install any connectors or components that were disconnected or removed.
Turn on the ignition switch.
Clear any DTCs.
Is the repair complete?



U1096 - Loss of Communications with IPC

The computers on the Chevy require a certain voltage to operate and if the voltage drops below a preset limit then it will tripper a loss of communication with the other modules, this drop in voltage happens when the car is started and the draw on the starter uses a large amount of amperage. I suggest to check power/ground in the instrument cluster and if good do a resistance test on Data wire.

If your car is not experincing any messages like "service vehicle soon" and no warning lights are illuminating then disregard these codes.


Hope helps.

try turning the steering wheel while you turn the key

Power to many of this vehicle's circuits are controlled by the module that is designated the Power Mode Master (PMM). This vehicle's PMM is the Body Control Module (BCM). The PMM controls which power mode (Run, Accessory, Crank, or Off) is active.
Serial Data Power Mode
On vehicles that have several control modules connected by serial data circuits, one module is the Power Mode Master (PMM). The BCM is the PMM on this vehicle. The PMM receives 3 discrete ignition switch signals to differentiate which power mode will be sent over the Class 2 Serial Data circuit.
To determine the correct power mode the PMM uses the following circuits:
• Ignition 0
• Ignition 1
• Ignition 3

Discrete Ignition Signals
Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open, or 0 volts, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.
Do you know what class 2 is ?

Class 2 Serial Data Link
The following modules use the class 2 serial data link to communicate with each other:
• The body control module (BCM)
• The digital radio receiver (DRR)
• The electronic brake control module (EBCM)
• The inflatable restraint sensing and diagnostic module (SDM)
• The powertrain control module (PCM)
• The radio
• The vehicle theft deterrent (VTD)
The class 2 serial data link also allows a scan tool to communicate with the above modules for diagnostic and testing purposes.
The class 2 serial data link on this vehicle is configured in a star pattern. There is no redundant path for the serial data to flow through. If a class 2 serial data circuit develops an open condition, the module connected by that circuit will not be able to communicate.

It is an electronic starter. ????? No it's not ! View a starter circuit here at http://www.bbbind.com/free_tsb.html Enter vehicle info. under system click on engine ,then under sub system click starting .