Data Communication System: Diagnosis Chevrolet Aveo I facelift

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Circuit Description

Modules that are connected to the shared communication circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have pre-recorded information about what messages are needed to be exchanged on the serial data circuits for each virtual network. The messages are usually supervised and some periodic messages are used by the receiver module as an availability indication of the transmitter module.

DTC Descriptors

This diagnostic procedure supports the following DTC

DTC U0101 Lost Communication With Transmission Control Module (TCM)

Conditions for Running the DTCs

1. The ignition is ON.
2. The DTC U0101 diagnostic runs continuously when the above condition is met.

Conditions for Setting the DTC

The engine control module (ECM) cannot communicate with the TCM.

Action Taken When the DTC Sets

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the system. Refer to «Checking Aftermarket Accessories»(ref-300847-S33638130562008101600000) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Scan Tool Does Not Power Up»(ref-300869-S07534338862008101600000)
2. «Scan Tool Does Not Communicate with CAN Device»(ref-300869-S34963452092008101600000)

The data link connector (DLC) provides operating power for the scan tool at terminal 16. The ground for the scan tool is provided at terminal 4. The 16- pin DLC provides the serial data signals at terminals 7 (engine control module (ECM), transmission control module (TCM), immobilizer serial data), 8 (theft deterrent serial data), 12 (ABS serial data), and 13 (SIR serial data). The scan tool will power up with the ignition OFF. The ignition must be ON in order for the scan tool to communicate with a control module.

The provisions for communicating with the engine control module (ECM), electronic brake control module (EBCM), SIR module, immobilizer module, and the theft deterrent module are located in the data link connector (DLC). The DLC is located under the instrument panel (I/P). The 16 pin DLC provides the serial data signals at terminals 7 (ECM, TCM, immobilizer serial data), 8 (theft deterrent serial data), 12 (ABS serial data), and 13 (SIR serial data). The DLC is used to link a scan tool to the ECM, EBCM, SIR, immobilizer, and theft control modules serial data stream. Some common uses of the scan tool are listed below

1. Identifying the stored diagnostic trouble codes (DTCs)
2. Reading the serial data stream
3. Clearing the DTCs
4. Storing the Freeze Frame data

Diagnostic Aids

Some scan tools may require an external power supply. Ensure the scan tool is correctly connected to the power feed.

Ensure that the correct application (model year, carline, VIN code) has been selected on the scan tool. If communications are still not established, try the scan tool on another vehicle in order to ensure that the scan tool or the connecting cables are not the cause of the malfunction. Always try the scan tool on a vehicle that uses the same DLC terminal for serial data communication.

Any circuitry that is suspect to an intermittent complaint should be thoroughly inspected for the following

1. Backed-out terminals
2. Improper mating of terminals
3. Broken electrical connector locks
4. Improperly formed or damaged terminals
5. Faulty terminal-to-wiring connections
6. Physical damage to the wiring harness
7. A broken conductor inside the wire insulation
8. Corrosion of the electrical connections, the splices, or the terminals

Regulations and agreements among the automobile manufacturers have resulted in the data link connector (DLC). This connector must be used for the scan tool and programming access to all communications systems used for the purposes on the vehicle. The connector must have the following

1. A 16-pin connector configuration to which all scan tools connect
2. Scan tool battery power always available at pin 16
3. Scan tool ground always available at pin 4
4. A clean signal ground always available at pin 5

The rest of the pins are available for serial data communications to the vehicle system. The serial data circuits are the means by which the microprocesor-controlled modules in the vehicle communicate with each other and the scan tool. There are 2 different types of protocols on this vehicle

1. The Universal Asynchronous Receiver Transmitter (UART)
2. Keyword 2000 Data line

The scan tool accesses the following module data lines

1. The electronic brake control module (EBCM) (UART)
2. The engine control module (ECM) (Keyword 2000)
3. The transmission control module (TCM) (UART)
4. The inflatable restraint sensing and diagnostic module (SDM) (UART)
5. The immobilizer control module (UART)
6. The anti-theft module (UART)