Cellular Communication System Cadillac STS I

Fastener Tightening Specifications

Fastener Tightening Specifications

Cellular Communication Schematic Icons

Cellular Communication Schematic Icons Icon Icon Definition IMPORTANT: Twisted wires provide an effective "shield" that helps protect sensitive electronic components from electrical interference. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted wires shown. The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the twisted triplet. The outside diameter of the twisted triplet must not exceed 5.8 mm (0.2 in) The drain wire must be wrapped around the twisted triplet a minimum of 3 turns for the length of the twisted triplet. The twisted triplet and the drain wire must be continuously covered by shield tape aluminum side inward. The shield tape must be covered with tape. Tubing must be against the back of the terminal insulation wings and secured at the other end with tape

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Cellular Communication Connector End Views

Vehicle Communication Interface Module (VCIM) C1 Connector End Connector Part Information OEM: 917981-1 Service: 16-Way M K11 Hybrid (WH) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 - - Not Used 2 BN/WH 2517 Keypad Red LED 3 YE/BK 2516 Keypad Green LED 4-5 - - Not Used 6 L-GN/BK 2515 Keypad Supply Voltage 7 BK 1050 Ground 8-10 - - Not Used 11 D-GN/WH 2514 Keypad Signal 12-14 - - Not used 15 RD/WH 2240 Battery Positive Voltage 16 - - Not Used

Vehicle Communication Interface Module (VCIM) C2 Connector End Connector Part Information OEM: 917975-1 Service: 12-Way F KII Hybrid (WH) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 D-BU 658 Cellular Telephone Voice Signal (w/YQ2/YQ3/YQ4) 2 L-BU/BK 659 Cellular Telephone Voice Low Reference (w/YQ2/YQ3/YQ4) 3-7 - - Not Used 8 BARE 814 Drain Wire (w/YQ2/YQ3/YQ4) 9 GY 655 Cellular Telephone Microphone Signal 10 BARE 1782 Drain Wire 11-12 - - Not Used

Vehicle Communication Interface Module (VCIM) C3 Connector End Connector Part Information OEM: 917981-1 Service: 16-Way F KII Hybrid (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 - - Not Used 2 PK 5149 Voice Recognition Audio Signal 3 - - Not Used 4 PK/BK 5152 Voice Recognition Audio Low Reference 5 BARE 1792 Drain Wire 6-16 - - Not Used

Vehicle Communication Interface Module (VCIM) C4 Connector End Connector Part Information OEM: 638695-2 Service: 12-Way F Tyco MK11 (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 D-GN 5060 Low Speed GMLAN Serial Data 2 TN/BK 2500 High Speed GMLAN Serial Data (+) (1) 3 TN 2501 High Speed GMLAN Serial Data (-) (1) 4-7 - - Not Used 8 TN/BK 2500 High Speed GMLAN Serial Data (+) (1) 9 TN 2501 High Speed GMLAN Serial Data (-) (1) 10-12 - - Not Used

Diagnostic Starting Point - Cellular Communication

Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. The system check will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored DTCs and their status

The use of the system check will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Data List (Gen 5)

Scan Tool Data List (Gen 5)

Scan Tool Data List (Gen 6.1)

Scan Tool Data List (Gen 6.1)

Circuit Description

This DTC is set as current in all vehicle communication interface module (VCIM) service parts and has been implemented as a reminder to contact the OnStar® Call Center to properly update the customers account once the new module has been installed. This call is initiated automatically after the installation of the replacement VCIM, and the completion of the Setup New VCIM procedure on the scan tool. No external circuits are involved.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC B1001 Option Configuration Error

Conditions for Running the DTC

The DTC is only run once per ignition cycle after a VCIM service part installation.

Conditions for Setting the DTC

This DTC is set as current in every VCIM service part, until the Setup New VCIM procedure on the scan tool has been performed after a service replacement.

Action Taken When the DTC Sets

1. The OnStar® status LED turns RED.
2. The blue OnStar® Call Center button is disabled.

Conditions for Clearing the DTC

A current DTC clears following the successful completion of the Setup New VCIM procedure via the scan tool.

DTC B1001

The vehicle communication interface module (VCIM) detects that the cellular microphone is connected through the cellular microphone signal circuit and the drain wire.

This diagnostic procedure supports the following DTC

DTC B2455 Cellular Phone Microphone Circuit Malfunction

1. The ignition must be in the RUN or ACC position.
2. The system voltage is at least 9.5 volts and no more than 15.5 volts.
3. All the above conditions are present for greater than 10 seconds.

1. The VCIM detects an open in the drain wire circuit or a short to voltage in the cellular microphone signal circuit.
2. The above conditions are present for greater than 10 seconds.

1. The VCIM will not receive any signal from the microphone.
2. Calls can be placed but the caller cannot be heard.
3. The OnStar® status LED turns RED.

1. The VCIM detects the microphone connected for 5 consecutive 100 millisecond cycles.
2. A history DTC clears after 50 malfunction-free ignition cycles.
3. The VCIM receives the clear DTC command from the scan tool.

Test Description

The number below refers to the step number on the diagnostic table.

1. 2: This step checks that the VCIM is sending out the proper supply voltage.

DTC B2455

The cellular antenna is connected to the vehicle communication interface module (VCIM) with a RG-58 coax cable. The VCIM polls the data from the cellular antenna once every second.

This diagnostic procedure supports the following DTC

DTC B2470 Cellular Phone Antenna Circuit Malfunction

1. The ignition must be in the RUN or ACC position.
2. The system voltage is at least 9.5 volts and no more than 15.5 volts.
3. All the above conditions are present for greater than 1 second.

1. The VCIM does not detect the presence of a cellular antenna.
2. All the above conditions are present for greater than 1 second.

1. The OnStar® status LED turns RED.
2. The vehicle is unable to connect to the OnStar® Call Center.

1. The VCIM detects the presence of a cellular antenna.
2. A history DTC clears after 50 malfunction free ignition cycles.
3. The VCIM receives the clear DTC command from the scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step tests the condition of the cellular antenna.
2. 3: This step tests the condition of the cellular antenna coax and for proper ground of the cellular antenna.

DTC B2470

The OnStar® button assembly consists of 3 buttons, Call/Answer, OnStar® Call Center, and OnStar® Emergency. Ten volts are supplied to the button assembly on the keypad supply voltage circuit. Each of the buttons, when pressed, complete the circuit across a resister allowing a specific voltage to be returned to the vehicle communication interface module (VCIM) on the keypad signal circuit. Depending upon the voltage range returned, the VCIM is able to identify which button has been pressed.

This diagnostic procedure supports the following DTC

DTC B2476 Cellular Phone Select Service Switch Malfunction (3 button assembly)

1. The ignition must be in the RUN or ACC position.
2. The system voltage is at least 9.5 volts and no more than 15.5 volts.
3. All the above conditions are present for greater than 300 milliseconds.

1. The VCIM powers the button assembly through the keypad supply voltage circuit for 11.5 milliseconds, turns the power off, then waits for 50 milliseconds and sees a voltage value greater than 1.8 volts on this circuit.
2. The above conditions are present for greater than 300 milliseconds.

1. The VCIM will ignore all inputs from the OnStar® button assembly.
2. No calls can be placed.
3. The OnStar® status LED turns RED.

1. The VCIM powers the button assembly through the keypad supply voltage circuit for 11.5 milliseconds, turns the power off, then waits for 50 milliseconds and sees a voltage value less than 1.8 volts on this circuit.
2. A history DTC clears after 50 malfunction-free ignition cycles.
3. The VCIM receives the clear DTC command from the scan tool.

The number below refers to the step number on the diagnostic table.

1. 2: This step checks that the VCIM is sending out the proper supply voltage.

DTC B2476

The OnStar® button assembly consists of 3 buttons, Call/Answer, OnStar® Call Center, and OnStar® Emergency. Ten volts are supplied to the button assembly on the keypad supply voltage circuit. Each of the buttons, when pressed, complete the circuit across a resister allowing a specific voltage to be returned to the vehicle communication interface module (VCIM) on the keypad signal circuit. Depending upon the voltage range returned, the VCIM is able to identify which button has been pressed.

This diagnostic procedure supports the following DTC

DTC B2482 Cellular Phone Select Switch Range/Performance

1. The ignition must be in the RUN or ACC position.
2. The system voltage is at least 9.5 volts and no more than 15.5 volts.
3. All the above conditions are present for greater than 15 seconds.

1. A button is pressed or stuck for more than 15 seconds.
2. The above conditions are present for greater than 15 seconds.

1. The VCIM will ignore all inputs from the OnStar® button assembly.
2. No calls can be placed.
3. The OnStar® status LED turns RED.

1. The button will be declared unstuck after a 50 milliseconds normal cycle.
2. A history DTC clears after 50 malfunction-free ignition cycles.
3. The VCIM receives the clear DTC command from the scan tool.

The number below refers to the step number on the diagnostic table.

1. 2: This step tests the at rest state of the keypad signal circuit.

DTC B2482

The navigation antenna is connected to the vehicle communication interface module (VCIM) with a RG-174 coax cable. The VCIM polls the data from the navigation antenna once every second.

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC B2483 GPS Sensor Circuit Low
2. DTC B2484 GPS Sensor Circuit Open

1. The ignition must be in the RUN or ACC position.
2. The system voltage is at least 9.5 volts and no more than 15.5 volts.
3. All the above conditions are present for greater than 1 second.

1. The VCIM does not detect a navigation signal.
2. All the above conditions are present for greater than 1 second.

1. The OnStar® status LED turns RED.
2. The OnStar® Call Center cannot locate the vehicle.

1. The VCIM detects the presence of a navigation antenna.
2. A history DTC clears after 50 malfunction free ignition cycles.
3. The VCIM receives the clear DTC command from the scan tool.

DTC B2483 or B2484

This DTC indicates an internal fault and is set within the vehicle communication interface module (VCIM). No external circuits are involved.

This diagnostic procedure supports the following DTC

DTC U1500 Inter-Device Dedicated Bus Malfunction

The microprocessor runs the program to detect an internal fault during module power up and every 10 seconds thereafter until the module re-enters the sleep mode.

The VCIM detects an internal communication malfunction.

Action Taken When DTC Sets

1. The OnStar® status LED turns RED.
2. The vehicle is unable to connect to the OnStar® Call Center.

1. A current DTC clears when the malfunction is no longer present.
2. A history DTC clears after 50 malfunction-free ignition cycles.

Diagnostic Aids

1. The diagnostic procedure used for DTC U1500 in OnStar® systems with single module generations of OnStar® differ greatly from previous generations with 2 modules. While these older generations denoted a failure of the 3-wire bus between the modules by setting a U1500, single module OnStar® systems use this DTC to denote an internal module failure. The determination of whether a one or 2-module generation of OnStar® is used should be confirmed. Refer to «OnStar Description and Operation»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system__onstar-description-and-operation) .
2. This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the VCIM.
3. If this DTC is retrieved as both a current and history DTC, replace the VCIM.

DTC U1500

System Description

This symptom table will enable the user to verify the customer complaint and narrow it to its source. If there is a concern with voice recognition or OnStar® steering wheel control function, technicians should proceed directly to the applicable diagnostic in Symptoms - Cellular Communication .

1. The customer concern may have been due to a lack of cellular service in a given area or a failure in the National Cellular Network infrastructure that has since been corrected.
2. If the prompt OnStar Request Ended is heard without pressing the white dot button at the end of an OnStar® keypress, the OnStar® system at one time made a successful cellular connection, but was unable to complete the call. If repeated calls are placed with this result, contact the General Motors Technical Assistance Center.
3. An inaccurate or aged global positioning system (GPS) position may have been due to the temporary loss of GPS signal reception by the vehicle in instances, such as driving through tunnels or parking structures which restrict the navigation antenna from a clear view of the satellites in the sky.

OnStar Symptom Diagnosis

Symptoms - Cellular Communication

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information. Before using the Symptom Tables, verify that all of the following are true: There are no DTCs set. The control module can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to «OnStar Description and Operation»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system__onstar-description-and-operation) .
3. Perform the «OnStar Symptom Diagnosis»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system) . This symptom table will enable the user to verify the customer complaint and narrow it to its source.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the system. Refer to «Checking Aftermarket Accessories»(/cadillac/sts/i-2004-2007/remont/body-electrical/#wiring-systems-electrical-power-management-introduction__checking-aftermarket-accessories) in Wiring Systems.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

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

1. «OnStar One or More Buttons Inoperative»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system__onstar-one-or-more-buttons-inoperative)
2. «OnStar Call Center Remote Function Requests Inoperative»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system)
3. «Unable to Contact OnStar Call Center»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system)
4. «Microphone Inoperative - Caller Cannot Be Heard»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system__microphone-inoperative-caller-cannot-be)
5. «Voice Recognition Inoperative»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system__voice-recognition-inoperative)
6. «OnStar Steering Wheel Control Functions Inoperative»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system__onstar-steering-wheel-control-functions-inoperative)
7. «OnStar Button LED Inoperative»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system)
8. «No (or Noisy) OnStar Audio»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system)
9. «Global Positioning System (GPS) Data Not Current or Inaccurate»(/cadillac/sts/i-2004-2007/remont/entertainment-systems/#cellular-communication-system)

OnStar One or More Buttons Inoperative

OnStar One or More Buttons Inoperative

The customer concern may have been due to a lack of cellular service in a given area or a failure in the National Cellular Network infrastructure that has since been corrected.

OnStar Call Center Remote Function Requests Inoperative

1. The customer concern may have been due to a lack of cellular service in a given area. A failure in the National Cellular Network infrastructure at the time of the customer's failed connection that has since been repaired may also have been the cause.
2. If an OnStar® emergency call is able to successfully connect the vehicle to the OnStar® Call Center when an OnStar® Call Center button press is not, there may be a failure in the ability of the OnStar® system in the vehicle to be recognized by the local cellular carrier.
3. If the prompt "OnStar® request ended" is heard, without pressing the white dot button at the end of the OnStar® keypress, the OnStar® system at one time has made a successful cellular connection, but was unable to complete the call. If repeated calls are placed with this result, contact General Motors Technical Assistance Center.

Unable to Contact OnStar Call Center

Microphone Inoperative - Caller Cannot Be Heard

Microphone Inoperative - Caller Cannot Be Heard

Voice Recognition Inoperative

Voice Recognition Inoperative

OnStar Steering Wheel Control Functions Inoperative

Some vehicles equipped with the OnStar® system have the capability of accessing voice mailboxes and other automated phone systems by means of the steering wheel controls, while the OnStar® Personal Calling (OPC) feature is in use. If the "Talk" or "Mute" button (depending upon the vehicle) on the steering wheel controls are depressed during an OPC call, the vehicle communication interface module (VCIM) receives the message on the class 2 or GMLAN serial data bus from either the radio, driver information module, or body control module. This message is interpreted as a request to turn any spoken numbers into dual tone multi-frequency (DTMF) tones to be delivered over the airwaves to the phone system the user is communicating with. Complete instructions for operation of these features can be found in the information provided to the customer with the OnStar® system.

The steering wheel controls are a resistor network that consist of multiple momentary contact switches and a series of resistors. The switches and resistor network are arranged so that each switch has a different resistance value. When a switch is pressed, a voltage drop occurs in the resistor network, which produces a specific voltage value unique to the switch selected, to be interpreted by either the radio, dash integration module, or body control module. In the event the OnStar® steering wheel control functions are inoperative, technicians should refer to Steering Wheel Controls Inoperative in Entertainment, to begin diagnosis of the steering wheel control concern.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step determines if the OnStar® status LED has the necessary GREEN LED signal circuit voltage.
2. 5: If the GREEN LED signal is shorted to voltage, then the OnStar® 3-button assembly has been damaged and must be replaced.

OnStar Button LED Inoperative

The number below refers to the step number on the diagnostic table.

1. 8: If the cellular telephone voice low reference circuit is shorted to voltage the vehicle communication interface module (VCIM) has been damaged and requires replacement.

No (or Noisy) OnStar Audio

1. The Global Positioning System (GPS) Signal title on the scan tool will display a Yes or No dependent upon whether or not the module sees an increment of the seconds transmitted by GPS signals to the vehicle communication interface module. Upon entering this screen, the GPS Signal title will automatically display Yes, regardless of the presence of time increment, for at least 2 seconds, while the algorithm in the scan tool determines the status of the clock. If increment is found, Yes is continually displayed. If the clock remains static, No is displayed. The scan tool looks for increment every second, regardless of current display.
2. Inaccurate or aged GPS position concerns which are no longer present may have been due to the temporary loss of GPS signal reception by the vehicle. Conditions such as driving through tunnels or parking structures while making an OnStar® keypress will restrict the navigation antenna from a clear view of the satellites in the sky and may have caused this temporary data loss.

Global Positioning System (GPS) Data Not Current or Inaccurate

OnStar Reconfiguration (Gen 6.1)

1. Install the scan tool. Use the ID information menu on the scan tool to access and record the new station ID (STID) and the electronic serial number (ESN) from the new VCIM.
2. Move the vehicle to an open area that is away from tall buildings with a clear view of unobstructed sky. Allow the vehicle to run for 10 minutes.
3. Use the special functions menu in order to begin the VCIM setup procedure for this vehicle.
4. Following this VCIM Setup procedure, a call will automatically be made to the OnStar® Call Center. Inform the Call Center Advisor of the following: Tell the advisor that this vehicle has received a new VCIM. Ask the advisor to add the new STID and the ESN to update the customer account. Ask the advisor to activate the OnStar® Personal Calling feature, if available. Follow any additional instructions from the OnStar® advisor.
5. Cycle the Ignition to complete the procedure and clear the B1001 DTC once the call to the OnStar® Call Center advisor is complete.

OnStar Reconfiguration (Gen 5)

1. Install the scan tool. Use the special functions menu in order to perform the VCIM setup procedure for this vehicle.
2. Move the vehicle to an open area that is away from tall buildings with a clear view of unobstructed sky. Allow the vehicle to run for 10 minutes.
3. Use the ID information menu on the scan tool to access the new station ID (STID) and the ESN from the new VCIM.
4. Press the blue OnStar® button to connect to the OnStar® Call Center and perform the following procedure: Tell the advisor that this vehicle has received a new VCIM. Ask the advisor to add the new STID and the ESN to update the customer account. Ask the advisor to activate the OnStar® Personal Calling feature, if available. Follow any additional instructions from the OnStar® advisor.
5. The default language for voice recognition in the generation 5 OnStar® module is English. To change the language resident in the module, refer to «Service Programming System (SPS)»(/cadillac/sts/i-2004-2007/remont/communication-devices/#programming-and-setup-all-systems__service-programming-system-sps) .

Removal Procedure

1. Remove the passenger side sail panel. Refer to «Sail Panel Replacement»(/cadillac/sts/i-2004-2007/remont/exteriorinterior-trim/#interior-trim) in Interior Trim
2. Lower the rear of the headliner to gain access to the coax cable. Refer to «Headliner Replacement»(/cadillac/sts/i-2004-2007/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
3. Remove the right rear compartment trim.
4. Disconnect the coax cable connectors. IMPORTANT: If replacing the cable with a new one cut the connector ends off and leave the old cable installed in the wire harness.
5. Remove the coax cable.

Installation Procedure

1. Install the coax cable.
2. Connect the electrical connectors.
3. Install the right side sail panel. Refer to «Sail Panel Replacement»(/cadillac/sts/i-2004-2007/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
4. Install the headliner. Refer to «Headliner Replacement»(/cadillac/sts/i-2004-2007/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

1. Remove the rear sail panels. Refer to «Sail Panel Replacement»(/cadillac/sts/i-2004-2007/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
2. Lower the rear of the headliner.
3. Remove the foam tape from the antenna cable connection.
4. Disconnect the antenna connectors (1).
5. Remove the antenna bolt (2) and expansion sleeve (3).
6. Remove the antenna.
7. Remove the screws securing antenna mast to the antenna base.
8. Remove the mast.

1. Install the antenna to the roof.
2. Route the wiring pigtail to the side in the slot on the antenna shaft and install the antenna expansion sleeve (3) and bolt (2) to the antenna shaft. Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. Connect the antenna connectors (1).
4. Wrap the connectors (1) with foam tape.
5. Install the antenna cable connection above the AM/FM antenna module.
6. Install the antenna cable hold down clips.
7. Align the headliner to the roof panel.
8. Install the rear sail panels. Refer to «Sail Panel Replacement»(/cadillac/sts/i-2004-2007/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
9. Locate the mast to the antenna base.
10. Install the screws securing the mast to the antenna base. Tighten: Tighten the screws to 1 N.m (9 lb in).

1. Remove the right rear compartment trim. Refer to «Compartment Trim Panel Replacement - Rear»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-rear-end) in Body Rear End.
2. Remove the nuts (2) securing the OnStar® module (1) to the vehicle body.
3. Disconnect all the electrical connectors from the module.
4. Remove the module from the vehicle.

1. When replacing the VCIM, record the 11-digit electronic serial number (ESN) and the 10-digit station identification (STID) number from the label on the new VCIM.
2. Reconnect the electrical connectors the module.
3. Install the module onto the vehicle. Tighten: Tighten the nuts to 9 N.m (80 lb in).
4. Install the scan tool. Use the special functions menu in order to perform the OnStar® setup procedure for this vehicle.
5. Move the vehicle to an open area that is away from tall buildings and with a clear view of unobstructed sky. Allow the vehicle to run for 10 minutes.
6. Use the ID information menu on the scan tool to access the new station ID (STID) and the electronic serial number (ESN) from the new VCIM.
7. Press the blue OnStar® button to connect to the OnStar® Call Center and perform the following procedure: Tell the advisor that this vehicle has received a new VCIM. Ask the advisor to add the new STID and the ESN to update the customer's account. Follow any additional instructions from the OnStar® advisor. Ask the advisor to activate the OnStar® Personal Calling feature, if available.
8. Voice recognition in the generation 4 module can NOT be changed. The default language for voice recognition in the generation 5 OnStar® module is English. To change the language resident in the module, refer to «Service Programming System (SPS)»(/cadillac/sts/i-2004-2007/remont/communication-devices/#programming-and-setup-all-systems__service-programming-system-sps) in Programming.

OnStar Description and Operation

This vehicle uses either the Generation 5 or Generation 6.1 version of the OnStar® system. These systems consist of the following components

1. Vehicle communication interface module (VCIM)
2. OnStar® button assembly
3. Microphone
4. Cellular antenna
5. Navigation antenna

This system also interfaces with the factory installed vehicle audio system.

Vehicle Communication Interface Module (VCIM)

The vehicle communication interface module (VCIM) is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused, battery positive, voltage circuit connected through the vehicle wiring to the 3-button assembly and the radio, and attached by means of coax cables to the cellular and navigation antennas. Ground for the module is accomplished by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the VCIM to be processed. The VCIM communicates with the rest of the vehicle over the class 2 or GMLAN serial data bus (depending upon the serial data architecture of the vehicle). The ignition state is determined by the VCIM through class 2 or GMLAN messaging. The module also has the capability of commanding the horn, initiating door lock/unlock and operating the exterior lamps using the serial data circuits. When an OnStar® keypress is made, a serial data message is sent to the audio system to mute all radio functions and transmit OnStar® originated audio. After the audio system is muted, the OnStar® signals are transmitted to the audio system on the cellular telephone voice signal circuit, and returned to the module on the cellular telephone voice low reference circuit. The cellular modem connects the OnStar® system to the cellular carrier's communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular antenna and cellular antenna coax.

OnStar® Button Assembly

The OnStar® button assembly may be part of the rearview mirror on some vehicles or a separate unit on others. The button assembly is comprised of 3 buttons and a status LED. The buttons are defined as follows

1. The answer/end call button, which is black with a white phone icon allows the user to answer and end calls or initiate the personal calling feature, if equipped.
2. The blue OnStar® call center button, which displays the OnStar® logo, allows the user to connect to the OnStar® call center.
3. The emergency button, which displays a white cross with a red background, sends a high priority emergency call to the OnStar® call center when pressed.

The OnStar® button assembly receives 10 volts on the keypad supply voltage circuit. When pressed, each button completes a circuit across a resister allowing a specific voltage to be returned to the vehicle communication interface module (VCIM) on the keypad signal circuit. Depending upon the voltage range returned, the VCIM is able to identify which button has been pressed.

The OnStar® status LED is located to the right of the emergency button on a mirror-mounted assembly and to the left of the answer/end call button when the assembly is mounted on the dash or overhead console. The LED is green when the system is ON and operating normally. When the status LED is green and flashing, it is an indication that a call is in progress. When the LED is red, this indicates a system malfunction is present. In the event there is a system malfunction and the OnStar® system is still able to make a call, the LED will flash red during the call. The OnStar® LED is controlled by the VCIM over the keypad red LED signal circuit and the keypad green LED signal circuit.

OnStar® Microphone

The OnStar®, or cellular microphone can be part of the rearview mirror assembly, or on some vehicle lines, can be a separate, stand alone unit. In either case, the microphone is supplied voltage on the cellular microphone signal circuit, while voice data from the user is sent back to the vehicle communication interface module (VCIM) by means of either a cellular microphone low reference circuit or a drain wire.

Cellular and Navigation Antennas

This vehicle will be equipped with one of the following types of antennas

1. Separate, standalone cellular and navigation antennas.
2. A combination cellular and navigation antenna, which brings the functions of both into a single part.
3. A cellular, navigation, and digital radio antenna, which also incorporates the functionality of the digital radio receiver satellite and terrestrial antennas (XM).

The cellular antenna is the component that allows the OnStar® system to send and receive data over airwaves by means of cellular technology. This antenna is connected at the base to a coax cable that plugs directly into the vehicle communication interface module (VCIM). The navigation antenna is used to collect the constant signals of the orbiting satellites. Within the antenna, is housed a low noise amplifier that allows for a more broad and precise reception of this data. The current global positioning system (GPS) location is collected by the module every time a keypress is made. The OnStar® Call Center also has the capability of pinging the vehicle during an OnStar® call, which commands the module to retrieve the latest GPS location and transmit it to the OnStar® Call Center. A history location of the last recorded position of the vehicle is stored in the module and marked as aged. In the event the VCP loses, or is removed from power, this history location is used by the OnStar® Call Center as a default. Actual GPS location may take up to 10 minutes to register in the event of a loss of power. This antenna requires a clear and unobstructed path to the satellites in the sky. Window tinting on vehicles may interfere with the GPS sensor functions, depending upon the location of the GPS antenna and the amount of darkening and/or metallic particles that are embedded in the film of the tinting material.

OnStar Sleep Cycle (Generation 5)

The OnStar® system uses a unique sleep cycle to allow the system to receive cellular calls while the ignition is in the OFF position. This cycle enables the vehicle communication interface module (VCIM) to perform remote functions, such as door unlock, as commanded over the air by the OnStar® Call Center, when requested by the customer, and to continue to maintain an acceptable level of battery electrical drain.

The OnStar® system uses 3 states of readiness

1. High power
2. Low power
3. Sleep

The high power state is in effect whenever the ignition is in the ON or RUN position, and enables the OnStar® system to send and receive cellular calls and perform all remote functions. The low power state is entered once the vehicle ignition is placed in the OFF position and the retained accessory power (RAP) function has been turned OFF, or times out. This state will last for 1 minute and allows incoming cellular calls to be received. After the 1 minute window, the OnStar® system moves to the sleep state. This state will not recognize or receive incoming cellular calls. At a predetermined time recorded within the VCIM, up to 9 minutes, the system re-enters the low power state to listen for a call from the OnStar® Call Center for 1 minute. After this interval, the system will again return to the sleep state for 9 minutes. After these 9 minutes, the system will again enter the low state of power and listen for any incoming calls that the OnStar® Call Center may be sending. In the event a call is being sent, the OnStar® system will receive the call and immediately go into the high power mode to perform any requested functions. If no call is received during the 1 minute interval, the system will go back into the sleep mode for another 9 minutes. This process will continue for up to 48 hours, after which, the OnStar® system will permanently enter the sleep state until the ignition is once again turned to the ON or RUN position.

In the event the OnStar® system loses, or is temporarily removed from battery power, the system will remain in the sleep state while the key in the OFF position. It will not begin to cycle until the vehicle passes into an open outside area with the ignition ON, where a global positioning system (GPS) signal can be acquired, providing a reference for time. The OnStar® Call Center is able to maintain a record of exactly what time each vehicle will enter the one minute low power state by synchronizing their clocks with those of the vehicle, based on GPS signals.

OnStar Sleep Cycle (Generation 6.1)

The OnStar® Generation 6.1 system uses a different sleep cycle than the Generation 5 system to allow the system to receive cellular calls while the ignition is in the OFF position. This cycle enables the vehicle communication interface module (VCIM) to perform remote functions, such as door unlock, as commanded over the air by the OnStar® Call Center, when requested by the customer, and to continue to maintain an acceptable level of battery electrical drain.

The OnStar® Generation 6.1 system varies by what type of cellular market it is in. If the vehicle is parked in an analog service only market, the sleep cycle works exactly the same as a Generation 5 system (see above). In a digital service market, the system uses the following 3 power modes when the vehicle is turned off

1. High Power
2. Digital Standby
3. Sleep

The high power state is in effect whenever the ignition is in the ON or RUN position, and enables the OnStar® system to send and receive cellular calls and perform all remote functions. The digital standby power state is in effect after the vehicle has been shut off and the retained accessory power (RAP) has timed out. When in digital standby mode, the OnStar module is able to perform all remote functions as commanded by an OnStar advisor at any time, for a continuous 8 hours. After 8 hours, the OnStar module will follow the standard sleep state that a Generation 5 module uses (9 minutes off, 1 minute of digital standby, based on the time of the GPS signals).

In the event the OnStar® system loses, or is temporarily removed from battery power, the system will remain in the sleep state while the key in the OFF position. It will not begin to cycle until the vehicle passes into an open outside area with the ignition ON, where a global positioning system (GPS) signal can be acquired, providing a reference for time. The OnStar® Call Center is able to maintain a record of exactly what time each vehicle will enter the one minute low power state by synchronizing their clocks with those of the vehicle, based on GPS signals.

Deactivated OnStar® Accounts

In the event a customer has not renewed their OnStar® account after expiration or the account was never activated, OnStar® will make a discrete cellular call to the vehicle to deactivate the OnStar® system. Before taking this action, customers are notified that the OnStar® system in their vehicle will be deactivated unless they elect to renew the account. After the vehicle has been successfully deactivated, customers will experience the following when attempting to contact OnStar® from their vehicle

1. During an OnStar® Call Center button press, the customer will be connected to a dedicated sales team who can sell an OnStar® subscription and reactivate the vehicle. Depending on the type of OnStar® hardware in the vehicle, the customer may first hear a demonstration message stating there is no current OnStar® subscription for the vehicle, and directing the customer what to do to activate services.
2. During an emergency button press, a demo message will be played indicating the service has been deactivated.
3. OnStar® personal calling (OPC) will not be available, as this feature requires the customer to have a current OnStar® account. Attempts to use this feature may result in cellular connection failure messages and the inability to connect to the number dialed.

It is of particular note, that when an OnStar® system is successfully deactivated, it will NOT attempt to connect to the OnStar® Call Center in the event of a collision or if the vehicles front air bags deploy for any other reason.

Certain vehicles that have never had an active OnStar® account, that have been deactivated, may be unable to establish a connection with the OnStar® Call Center. When normal published diagnostic procedures do not indicate a possible cause for the no connect concern, the vehicle may have been deactivated. For deactivated vehicles, a no connect response should be considered normal operation. Further diagnosis and subsequent repair is only necessary should the customer elect to become an active OnStar® subscriber.

OnStar® Reconfiguration Procedure

Within the vehicle communication interface module (VCIM) are a set of unique numbers that identify the OnStar® customer and the specific vehicle the module resides in. These numbers, the station identification number (STID) and the electronic serial number (ESN) are transmitted over the cellular network when an OnStar® keypress is made and are essential for proper identification and connection to the OnStar® Call Center. In the event the VCIM requires replacement, the OnStar® reconfiguration procedure must be performed. This procedure allows for the new STID and ESN within the replacement module to overwrite the old numbers and update customer and vehicle information at the OnStar® Call Center. The reconfiguration process is explained within the VCIM replacement procedure, or the OnStar® Reconfiguration Procedure found in the Cellular Communication diagnostic information and procedures section.

OnStar® Cellular, GPS, and Diagnostic Limitations

The proper operation of the OnStar® System is dependent on several elements outside the components integrated into the vehicle. These include the National Cellular Network Infrastructure, the cellular telephone carriers within the network, and the global positioning system (GPS) system.

The cellular operation of the OnStar® system may be inhibited by factors such as the user's range from an analog (Generation 5) or digital (Generation 6.1) cellular tower, the state of the cellular carriers' equipment, and the location where the call is placed. Making an OnStar® keypress in areas that lack sufficient cellular coverage or have a temporary equipment failure will result in either the inability of a call to complete with a data transfer or the complete inability to connect to the OnStar® Call Center. The OnStar® system may also experience connection issues if the identification numbers for the module, station identification number (STID) and electronic serial number (ESN), are not recognized by the cellular carriers local signal receiving towers. OnStar® cellular connection issues such as these require the assistance of the General Motors Technical Assistance Center OnStar® Group, which coordinates with cellular carriers to resolve connection issues.

The satellites that orbit earth providing the OnStar system with GPS data have almost no failures associated with them. In the event of a no GPS concern, the failure will likely lie with the inability of the system to gain GPS signals because of its location, i.e. in a parking structure, hardware failure, or being mistaken with an OnStar® call which has reached the Call Center without vehicle data.

During diagnostic testing of the OnStar® system, the technician should ensure the vehicle is located in an area that has a clear unobstructed view of the open sky, and preferably, an area where analog (Generation 5) or digital (Generation 6.1) cellular calls have been successfully placed. These areas can be found by successfully making an OnStar® keypress in a known good OnStar® equipped vehicle and confirming success with the OnStar® Call Center advisor. Such places can be used as a permanent reference for future OnStar® testing.

OnStar® Personal Calling

The hand free, OnStar® personal calling (OPC) cellular phone feature is an additional option to the OnStar® system. This feature is already embedded within the vehicle communication interface module (VCIM), however, it must be activated by an OnStar® advisor. This is done most often during the initial OnStar® configuration, if the home location of the vehicle is in a geographic area where OnStar® personal calling is available. In the event this feature is not enabled, customers may connect to the OnStar® Call Center by pressing the blue OnStar® button, and asking an advisor if OPC is available in their area. Users of the Generation 5 or Generation 6.1 OnStar® system can verify the system has been configured for OnStar® Personal Calling by pressing the answer/end call button, waiting for the system to respond "OnStar Ready" then speaking the word "dial." If the system responds with a failure message, the system has not been configured for OPC. All other responses confirm that OPC has been enabled.

Operation of the Hands Free Cellular Phone

Onstar® personal calling (OPC) operates similar to most hand held cellular phones in that the availability for its usage is based on minutes or units. The customer must have a current OnStar® subscription, as this feature cannot be utilized without it. To use OPC, the customer must also purchase units as outlined in the owners guide provided with the OnStar® system. When the customer purchases minutes, an OnStar® advisor loads these minutes into the vehicle communication interface module (VCIM) over the airwaves at the time of the request, or through a discrete cellular call to the vehicle at a later time. Once loaded into the module, the units may be used for non-international, outbound cellular phone calls, and connection with the OnStar® virtual advisor. Units begin to deplete, one unit is equal to one minute, as the customer makes outbound phone calls, answers inbound phone calls, or while connected to the OnStar® virtual advisor. In addition, units also have an expiration date, depending upon the type of units purchased. This date is established when the download is performed, and any remaining units expire when the date within the VCIM, which is based on current date and the time transmitted by global positioning system (GPS) satellites, has passed. At any time, the user can press the answer/end call button, say "Units" and verify the number of units remaining.

During a hands free call, the microphone and audio system operate the same way as a standard OnStar® call. When the answer/end call button is pressed, the audio system will mute; the OnStar® system will then return the prompt "OnStar Ready." At this point there are specific commands set to initiate a cellular call. If the vehicle receives a call when the radio is ON, the audio system will mute and an audible ring will be heard though the speakers. The call will be answered when the answer/end call button is pressed.

The VCIM interprets all of the voice-activated commands. A complete list of these commands is supplied in the information provided to the customer. If the information is not available to reference, at any command prompt the caller can say "HELP" and the VCIM will return an audible list of available commands. If the customer concern is not being understood or not being heard by the OnStar® system, the user should place a call to the OnStar® call center to verify proper operation of the microphone. Following this description is an example of the commands and the OnStar® system responses. A complete list of commands is supplied in the information provided to the customer with the OnStar® system.

OnStar® Steering Wheel Controls

Some vehicles equipped with the OnStar® system have the capability of accessing voice mailboxes and other automated phone systems by means of the steering wheel controls, while the OnStar® personal calling (OPC) feature is in use. If the Talk or Mute button, depending upon the vehicle, on the steering wheel controls are depressed during an OPC call, the vehicle communication module (VCIM) receives the message on the class 2 serial data bus from either the radio, the driver information module, or the body control module (BCM). This message is interpreted as a request to turn any spoken numbers into dual tone multi-frequency (DTMF) tones to be delivered over the airwaves to the phone system the user is communicating with. Complete instructions for operation of these features can be found in the information provided to the customer with the OnStar® system.

The steering wheel controls are a resistor network that consist of multiple momentary contact switches and a series of resistors. The switches and resistor network are arranged so that each switch has a different resistance value. When a switch is pressed, a voltage drop occurs in the resistor network, which produces a specific voltage value unique to the switch selected, to be interpreted by either the radio, driver information module, or body control module.

OPC Features

The following is an abbreviated list of features that may have an impact for the technician when servicing or diagnosing an OnStar® system. For a full list of OnStar® Personal Calling features, consult the owner's guide provided to the customer with the OnStar® system.

Voice Feedback

The OnStar® Personal Calling (OPC) system has the capability of responding to the user with either an automated voice response or with a tone or beep. These 2 types of responses can be switched back and forth by pressing the answer/end call button, waiting for the system to respond "OnStar Ready" and speaking the phrase "voice feedback." The system will then respond, "voice feedback is now on/off."

OPC Security/System Lock

Customers have the capability to lock their OnStar® Personal Calling (OPC) system by pressing the answer/end call button, speaking "security" and entering a 4-digit code. Once this process is complete, the user must enter the code before OnStar® personal calling is available. In the event the customer cannot remember their code and is unable to use their system, they can press the blue OnStar button and speak to an advisor to unlock the system by means of a discrete cellular call to the vehicle.

Nametags

Customers have the ability to store telephone numbers within the module, referenced by a nametag for the convenience of frequently dialed numbers. This process is initiated by pressing the answer/end call button, waiting for the system response, then speaking the response "store". The system will respond with "number please" at which time the user should enter the number desired to be stored. Once complete, saying the word "store" again lets the system know you are finished entering the number. At this time, the system will elicit the user to assign a nametag to that number. From this point forward, the user can dial this number by initiating the OnStar® personal calling (OPC) feature, speaking the word "call," and repeating the nametag assigned. To delete a nametag, the user should initiate OPC, say "delete" then speak the nametag to be removed. In the event a nametag cannot be deleted in spite of repeated attempts from several speakers, the OnStar® module will require replacement.

Mobile Identification Number and Mobile Directory Number

The Generation 5 and Generation 6.1 vehicle communication interface modules (VCIM) utilize 2 numbers for cellular device identification, call routing and connection, a mobile identification number (MIN) and a mobile directory number (MDN). The MIN represents the number used by the cellular carrier for call routing purposes while the MDN represents the number dialed to reach the cellular devise. Although technicians have the capability to change these numbers by means of the scan tool, this should ONLY be done at the direction of and with explicit instruction from General Motors Technical Assistance Center (GM TAC).

Dialing a Phone Number Hands Free (Generation 5)

Placing a Call (Generation 6.1)

To Dial a Number

After 3 unsuccessful tries, or if you simply like it better, you can use the "Digit Dial" command to input digits one at a time. Digit Dial is set up to dial phone numbers like previous OnStar Personal Calling Systems (Generation 5).

To Dial a Number Using Digit Dial

To Place a Call Using a Stored Nametag

To Place a Call Using the "Redial" Command

Operation of the OnStar® Speech Recognition Systems

OnStar® Generation 5 and Generation 6.1 users communicate with 2 speech recognition systems. Speech recognition allows the user to speak to one computer in the vehicle, and one reached over a phone line. The computer tries to understand the user's command, and responds by speaking back, or by taking the appropriate action, e.g. dialing the phone.

1. Personal Calling uses a speech recognition system that resides in the vehicle. When the user presses the dot button, the system states, Ready, and listens for the user's command. The user can speak commands to control the hands-free phone.
2. Virtual advisor is a remote speech recognition system that the caller access by making a phone call. The user connects to virtual advisor by requesting it during personal calling use. The user is then transferred to the virtual advisor server and talks to it via a cellular connection.

The OnStar® speech recognition systems use speech technology that is designed to understand a wide range of American English speakers. Although there is no one right way to speak English, the system will work best when users try to modify their pronunciation should they encounter difficulty. Users who do not obtain good results are advised to try the tips and workarounds found in this section.

General Tips for Better Speech Recognition

Personal Calling Commands

See also:
• Diagnostic System Check - Vehicle
• Circuit Testing
• Wiring Repairs
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Rearview Mirror Replacement (UE1)
• Control Module References
• Checking Aftermarket Accessories
• Diagnostic Starting Point - Horns
• Diagnostic Starting Point - Lighting Systems
• Diagnostic Starting Point - Doors
• Steering Wheel Controls Inoperative
• Diagnostic Starting Point - Entertainment
• Service Programming System (SPS)
• Sail Panel Replacement
• Fastener Notice
• Compartment Trim Panel Replacement - Rear
• OnStar Reconfiguration (Gen 6.1)
• OnStar Reconfiguration (Gen 5)
• Communication Interface Module Replacement
• Cellular Communication Connector End Views
• OnStar Description and Operation
• Symptoms - Cellular Communication
• OnStar One or More Buttons Inoperative
• Microphone Inoperative - Caller Cannot Be Heard
• Voice Recognition Inoperative
• OnStar Steering Wheel Control Functions Inoperative