Information System & Entertainment System: Overview Ford Escape II

Principles of Operation

Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

Normal Operation

The AM/FM antenna receives AM and FM radio waves. The antenna cable transfers the radio waves to the Audio Control Module (ACM).

The noise suppression equipment reduces engine ignition and electrical systems interference transmitted through the speakers.

The RDS function allows the vehicle operator to choose which genre (category) of music to listen to. When the SCAN button is pressed, the ACM only stops at songs falling within the selected category. If no song in the selected category is found, the ACM continues to scan without stopping. This may appear to be a reception issue, but it is actually due to the customer setting.

1. DTC B1A56:21 (Antenna: Signal Amplitude < Minimum) - sets when the signal strength is less than the pre-configured threshold value during the ACM self-test. This DTC applies to vehicles with navigation only.
2. DTC B2103 (Antenna Not Connected) - sets when the signal strength is less than the pre-configured threshold value during the ACM self-test. In order for this DTC to set, the ACM must be tuned to AM, and the self-test must be run with the scan tool. This DTC applies to vehicles without navigation only.

This pinpoint test is intended to diagnose the following

1. No song found in the selected category
2. Antenna
3. Antenna cable
4. Charging system
5. Ignition system
6. Noise suppression equipment
7. ACM

The Audio Control Module (ACM) directs audio signals to the speakers in the form of an AC voltage. The ACM provides internal circuit protection for shorts to ground or shorts to voltage. The tweeter speakers are integral to the front door speakers, and cannot be replaced separately.

A short to ground or short to voltage in the circuitry to one of the speakers can cause multiple speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, a speaker fault DTC sets, and this pinpoint test should be followed to isolate the damaged circuit.

It should also be noted that when the ACM activates the built-in overload protection, DTC B1342 can also set. The circuit failure must be repaired before DTC B1342 can be cleared.

1. DTC B2965 (Audio System Speaker Circuit Fault) - sets when an open, short to ground, or short to voltage is detected on any of the speaker circuits.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Speaker
3. ACM

When the ignition is in the START position, voltage is supplied to the Audio Control Module (ACM) through circuit CBP28 (GY/VT). When the ACM receives this voltage, it mutes the speaker output to prevent popping in the speakers as a result of voltage spikes during engine cranking, However, if there is a short to voltage on this circuit, the ACM will continually mute the audio output, resulting in no sound from all speakers.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. ACM

The subwoofer amplifier receives voltage through circuit SBP38 (BN/RD) and ground through circuit GD151 (BK/GN). The subwoofer amplifier can be replaced individually; however, the subwoofer speaker is only replaceable as an assembly with the enclosure and subwoofer amplifier.

To enable the subwoofer amplifier, the Audio Control Module (ACM) sends voltage through the enable/clip circuit SME23 (VT/RD). The circuit acts as both an output (to enable the amplifier) and an input (to detect an amplifier overload condition). A variable resistor in the subwoofer amplifier modifies the voltage signal from the ACM. In the event of an overload, the ACM clips the audio output signal to the amplifier (heard as distortion), in order to prevent damage to the amplifier and speaker.

The clip/enable status is based on the following voltages, as detected by the ACM

1. Less than 0.4 volt: amplifier disabled
2. Between 3.8 and 6.7 volts: amplifier enabled
3. Greater than 8.5 volts: amplifier clipped

An open in circuit SME23 (VT/RD) causes the subwoofer to produce no sound, because the enable signal does not reach the subwoofer amplifier. A short to ground or short to voltage can cause severe distortion to be heard in the subwoofer.

1. DTC BlA05:01 (Speaker #5: General Electrical Failure) - sets when an open, a short to ground, or a short to voltage is detected in the audio output circuits to the subwoofer.

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Subwoofer amplifier
4. Subwoofer speaker
5. ACM

Voltage is sent through the start input circuit CBP28 (GY/VT) to the Audio Control Module (ACM) with the ignition in the START position. Upon receiving this signal, the ACM mutes all speaker outputs to eliminate the possibility of voltage spikes producing a popping noise through the speakers.

For the Audiophile audio system, the ACM disables the subwoofer while the ignition is in the START position by keeping the enable signal below 0.4 volt on circuit SME23 (VT/RD). If there is a short to voltage on circuit SME23 (VT/RD), distortion will be heard in the subwoofer whenever the ACM is powered up, and that should be the primary concern addressed. If the subwoofer has distorted sound, GO to PINPOINT TEST D .

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Subwoofer (Audiophile)
4. ACM

There are 4 different steering wheel controls configurations

1. Non-navigation, without the SYNC system VOL-, VOL+, SEEK-, SEEK+, MEDIA All switches are wired to the Audio Control Module (ACM).
2. Non-navigation, with the SYNC system VOL-, VOL+, SEEK-, SEEK+, VOICE, MEDIA, PHONE, OK The VOL-, VOL+, SEEK-, and SEEK+ switches are wired to the ACM. The remaining switches are wired to the Accessory Protocol Interface Module (APIM).
3. Navigation, without the SYNC system VOL-, VOL+, SEEK-, SEEK+, VOICE, MEDIA All switches are wired to the ACM.
4. Navigation, with the SYNC system VOL-, VOL+, SEEK-, SEEK+, VOICE, MEDIA, PHONE All switches are wired to the ACM.

Voltage is sent from the APIM (or ACM) to the steering wheel controls, and the same module grounds the return circuit. The VOL-, VOL+, SEEK-, and SEEK+ switches share signal and return circuits, while the VOICE, MEDIA, PHONE, and OK switches share separate signal and return circuits.

For all configurations, when a switch is pressed, the voltage is routed through a specific resistor value for each function. The ACM (or APIM) then uses the reference voltage to determine which control input function has been selected.

DTC DESCRIPTION CHART

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Clock spring
3. Steering wheel controls
4. ACM
5. APIM

The speed sensitive volume function, available with all audio systems except the base AM/FM/Single CD, adjusts the volume based on the Vehicle Speed Sensor (VSS) signal from the Instrument Cluster (IC). The IC does not generate the VSS signal; it gateways the signal from the PCM. The Smart Junction Box (SJB) also receives this signal and should exhibit symptoms if the signal is lost.

1. DTC U0155 (Lost Communication With Instrument Panel Cluster (IC) Module) - set by the non-navigation Audio Control Module (ACM) when the VSS signal is lost for greater than 5 seconds. When the signal is lost, the ACM turns the speed sensitive volume feature off.
2. DTC U0155:00 (Lost Communication With Instrument Panel Cluster (IPC) Control Module) - set by the ACM when the VSS signal is lost for greater than 5 seconds. When the signal is lost, the ACM turns the speed sensitive volume feature off.

This pinpoint test is intended to diagnose the following

1. Speed sensitive volume setting
2. VSS signal concern
3. ACM

Normal Operation - Vehicles Without The SYNC System

Audio signals are sent from the audio input jack to the Audio Control Module (ACM). There are no external power or ground circuits to the audio input jack.

The Front Display Interface Module (FDIM) receives voltage through circuit SBP14 (BN/RD), and ground through circuit GD114 (BK/BU). The ignition switch position message is sent to the FDIM by the Smart Junction Box (SJB) via the Medium Speed Controller Area Network (MS-CAN).

Information from the audio system (vehicles without navigation), the climate control system, the SYNC system (if equipped), and the compass heading (if equipped) are shown on the FDIM display screen. If only one of these displays has a concern, GO to PINPOINT TEST K .

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. FDIM

The Audio Control Module (ACM) receives inputs via the Medium Speed Controller Area Network (MS-CAN) from the following modules

1. Accessory Protocol Interface Module (APIM): SYNC system information
2. HVAC module: climate control system information

If the ACM loses the signal from any of these modules, only that specific display will be inoperative.

Because the satellite radio receiver is internal to the ACM, all satellite radio information on the display is directly generated by the ACM.

For the compass display, this pinpoint test is intended to diagnose a concern of the compass display being blank. For any other concerns with the compass display, including the compass being inaccurate, refer to ELECTRONIC COMPASS .

1. DTC U0164:00 (Lost Communication With HVAC Control Module: No Sub Type Information) - set by the ACM if it does not receive status messages from the HVAC module for greater than 5 seconds with the ignition in the RUN position. When this occurs, the ACM may not display correct (if any) climate control information.
2. DTC U0197:00 (Lost Communication With Telephone Control Module: No Sub Type Information) - set by the ACM if it does not receive status messages from the APIM for greater than 5 seconds with the ignition in the RUN position. When this occurs, the FDIM may not display correct (if any) SYNC system information. If the SYNC system is completely inoperative, GO to «PINPOINT TEST X»(ref-344106-S29681984082009101600000) .

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. ACM

The Front Display Interface Module (FDIM) receives inputs via the Medium Speed Controller Area Network (MS-CAN) from the following modules

1. Audio Control Module (ACM): audio system information
2. Satellite Digital Audio Receiver System (SDARS) module: satellite radio information
3. Instrument Cluster (IC): compass heading information
4. Accessory Protocol Interface Module (APIM): SYNC system information
5. HVAC module: climate control system information

If the FDIM loses the signal from any of these modules, only that specific display will be inoperative.

For the compass display, this pinpoint test is intended to diagnose a concern of the compass display being blank. For any other concerns with the compass display, including the compass being inaccurate, refer to ELECTRONIC COMPASS .

DTC DESCRIPTION

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. FDIM

Digital signals are received by the satellite radio antenna and sent to the Satellite Digital Audio Receiver System (SDARS) module. The digital audio signals are converted to analog and sent to the Audio Control Module (ACM) (vehicles without the SYNC system) or the Accessory Protocol Interface Module (APIM) (vehicles with the SYNC system). For vehicles with the SYNC system, the audio signals are sent to the ACM from the APIM.

When a satellite radio subscription is activated, the Electronic Serial Number (ESN) of the SDARS module is associated with the Vehicle Identification Number (VIN). As a result, the SDARS module cannot be swapped from one vehicle to another.

In order for the satellite radio system to operate, messages are sent from the Front Controls Interface Module (FCIM) to the ACM and the SDARS module when a button is pressed. The ACM or SDARS module responds with the appropriate function. The SDARS module also sends messages to the Front Display Interface Module (FDIM) in order to display satellite radio information on the display screen.

If there is an open in the satellite radio antenna circuit, there will be no satellite audio. The audio system display indicates a satellite antenna concern (the method varies according to the type of ACM) when the audio system is operated in satellite radio mode. To diagnose an open in the satellite radio antenna circuit, GO to PINPOINT TEST M .

DTC DESCRIPTION

This pinpoint test is intended to diagnose the following

1. Subscription status
2. Audio system concern
3. SDARS module

Normal Operation - Vehicles With External Satellite Radio Receiver

Digital signals are received by the satellite radio antenna and sent to the Satellite Digital Audio Receiver System (SDARS) module, which then converts the signals and provides audio signals to the Audio Control Module (ACM). If the vehicle is equipped with the SYNC system, the audio signals route through the Accessory Protocol Interface Module (APIM) before routing to the ACM.

The Global Positioning System (GPS) antenna (integral to the satellite radio antenna) provides information from the GPS satellite system to the Audio Control Module (ACM). This information is used to calculate vehicle position and direction of travel.

A splitter is used in the lower satellite radio antenna cable to split the signals between the satellite radio and the GPS. It is possible that a concern in the GPS signal line after the splitter may cause a navigation system concern without affecting the satellite radio.

1. DTC B119F:01 (GPS Antenna: General Electrical Failure) - sets when any failure is detected in the GPS antenna circuit.
2. DTC B119F:13 (GPS Antenna: Circuit Open) - sets when an open is detected in the GPS antenna circuit.

This pinpoint test is intended to diagnose the following

1. Satellite radio antenna cable
2. ACM

The primary source of vehicle location for the navigation system is the Audio Control Module (ACM) receiving the position signal through the Global Positioning System (GPS) antenna.

In addition, the ACM receives the navigation rolling wheel count signal from the Instrument Cluster (IC) (which gateways the signal from the ABS module). This secondary signal is used to calculate vehicle position when the GPS signal is lost. It also supports the adaptive learning function of the ACM, whereby the ACM can compensate for long-term differences between the GPS signal location and the actual distance traveled by the vehicle.

If DTC B119F:01 or B119F:13 is present, GO to PINPOINT TEST N to diagnose a concern with the GPS antenna.

1. DTC U0155:00 (Lost Communication With Instrument Panel Cluster (IPC) Control Module) - sets when the ACM is missing the navigation rolling wheel count message from the IC for greater than 5 seconds. An error message should be displayed on the navigation screen if this signal is missing.

This pinpoint test is intended to diagnose the following

1. GPS antenna concern
2. Communication network concern
3. ACM

The Audio Control Module (ACM) directs audio signals to the audio amplifier in the form of an AC voltage. The ACM provides internal circuit protection for shorts to ground or shorts to voltage. The tweeter speakers are integral to the front door speakers, and cannot be replaced separately.

A short to ground or short to voltage in the circuitry to the audio amplifier can cause multiple speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, a speaker fault DTC sets, and this pinpoint test should be followed to isolate the damaged circuit.

It should also be noted that when the ACM activates the built-in overload protection, DTC B1342 can also set. The circuit failure must be repaired before DTC B1342 can be cleared.

To enable the audio amplifier, the ACM sends voltage through the enable/clip circuit CME27 (YE/VT). The circuit acts as both an output (to enable the amplifier) and an input (to detect an amplifier overload condition). A variable resistor in the audio amplifier modifies the voltage signal from the ACM. In the event of an overload, the ACM clips the audio output signal to the amplifier (heard as distortion), in order to prevent damage to the amplifier and speakers.

The clip/enable status is based on the following voltages, as detected by the ACM

1. Less than 0.4 volt: amplifier disabled
2. Between 3.8 and 6.7 volts: amplifier enabled
3. Greater than 8.5 volts: amplifier clipped

An open in circuit CME27 (YE/VT) causes the speakers to produce no sound, because the enable signal cannot reach the audio amplifier. A short to ground or short to voltage can cause severe distortion to be heard in the speakers. In either of these scenarios, the subwoofer should continue to operate correctly, as it utilizes a separate amplifier and clip/enable circuit.

DTC DESCRIPTION

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Speaker
4. Audio amplifier
5. ACM

When a button is pressed on the Audio Control Module (ACM) (whether it is a hard button or the touchscreen), a signal is sent over the Medium Speed Controller Area Network (MS-CAN) to the modules in the audio system.

1. DTC U2013:63 (Switch Pack: Circuit/Component Protection Time-Out) - sets in continuous memory when an ACM hard button is stuck for longer than 2 minutes, or during the on-demand self-test if an ACM hard button is detected as active for any duration. Make sure no ACM buttons are pressed during the self-test.

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. ACM

When a button is pressed on the Front Controls Interface Module (FCIM), a signal is sent over the Medium Speed Controller Area Network (MS-CAN) to the modules in the audio system.

If the FCIM can no longer communicate on the MS-CAN (due to loss of power, ground, etc.), the audio system remains in the operating state it was in prior to the failure. The steering wheel controls (if equipped) continue to operate.

DTC DESCRIPTION

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. ACM

Digital signals are received by the satellite radio antenna and sent to the Audio Control Module (ACM) through the satellite radio antenna cable. The satellite receiver is internal to the ACM.

If there is an open in the satellite radio antenna circuit, there will be no satellite audio. The audio system display indicates a satellite antenna concern when the audio system is operated in satellite radio mode. To diagnose an open in the satellite radio antenna circuit, GO to PINPOINT TEST M .

1. DTC U2014:96 (Control Module Hardware: Component Internal Failure) - sets when the navigation ACM detects an internal fault to the built-in satellite radio receiver. This results in complete loss of satellite radio functionality.

This pinpoint test is intended to diagnose the following

1. Subscription status
2. ACM

When the VOICE switch is pressed, it changes the reference voltage from the Audio Control Module (ACM) on circuit VME54 (BU/OG), and the ACM enters voice recognition mode. A microphone located in the auto-dimming interior mirror receives the voice command and sends a signal to the ACM through circuits VMM 13 (YE/GN) and RMM13 (BU). Power to the auto-dimming interior mirror is provided through circuit CBP41 (BU). Ground is provided through circuit GD182 (BK/GY).

The microphone test is available through the Integrated Diagnostic System (IDS) scan tool or through the ACM bezel test. Running this test causes the ACM to produce a test tone. If the system is operating correctly, the microphone detects the tone and produces a voltage signal to the ACM indicating the tone was heard.

1. DTC B1D79:01 (Microphone Input: General Electrical Failure) - set by the ACM during the microphone test when it does not receive an adequate signal from the microphone when the test tone is sounded.

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Steering wheel controls
4. Microphone (part of the auto-dimming interior mirror)
5. ACM

When the VOICE switch is pressed, it changes the reference voltage on circuit VME54 (BU/OG) and the audio system enters voice recognition mode. If the vehicle is equipped with navigation, the VOICE switch is wired to the Audio Control Module (ACM). If the vehicle is not equipped with navigation, the VOICE switch is wired to the Accessory Protocol Interface Module (APIM). A microphone located in the auto-dimming interior mirror receives the voice command and sends a signal to the APIM through circuits VMM 13 (YE/GN) and RMM13 (BU). Power to the auto-dimming interior mirror is provided through circuit CBP41 (BU). Ground is provided through circuit GD182 (BK/GY). The microphone is also used to detect outgoing audio during a phone call.

If the vehicle is equipped with navigation, the APIM receives the microphone input, and also broadcasts it to the ACM through circuits VMN01 (BU/BN) and RMN01 (GN). The first voice commands spoken determine which system handles the voice commands.

The microphone test (vehicles with navigation only) is available through the Integrated Diagnostic System (IDS) scan tool or by running the ACM bezel test. Running this test causes the ACM to produce a test tone. If the system is operating correctly, the microphone detects the tone and produces a signal to the ACM indicating the tone was heard.

1. DTC B1038 (Microphone Input Circuit Failure) - set by the APIM (VI) during the on-demand self-test if it does not detect the microphone.
2. DTC B1D79:01 (Microphone Input: General Electrical Failure) - set by the ACM or APIM (V2) during the microphone test when it does not receive an adequate signal from the microphone when the test tone is sounded.

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Steering wheel controls
4. Microphone (part of the auto-dimming interior mirror)
5. ACM (if equipped with navigation)
6. APIM

The Accessory Protocol Interface Module (APIM) receives voltage at all times from circuit SBP03 (BU/RD), and ground through circuit GD115 (BK/GY). The APIM communicates via the Medium Speed Controller Area Network (MS-CAN).

When a button on the Front Controls Interface Module (FCIM) (vehicles without navigation) or Audio Control Module (ACM) (vehicles with navigation) is pressed, a network message is sent to the APIM via the MS-CAN. The APIM takes the appropriate action and sends a status message to the Front Display Interface Module (FDIM) (vehicles without navigation) or the ACM (vehicles with navigation) in order to update the display screen.

DTC DESCRIPTION

This pinpoint test is intended to diagnose the following

1. Audio system concern
2. Communication network concern
3. Customer error
4. APIM
5. ACM

When a new Bluetooth device is added, the Accessory Protocol Interface Module (APIM) and the Bluetooth device must be paired together. Most Bluetooth devices can pair with the SYNC system, although functionality may vary. To determine if a Bluetooth device is supported, retrieve the Consumer Interface Processor (CIP) software level using the Accessory Protocol Interface Module (APIM) Software Level Check, and verify the customer device is on the compatibility list for the current CIP software level.

Pairing a Bluetooth device is accomplished through the "Add Device" selection of the phone menu. When pairing a device, the SYNC system generates a unique Personal Identification Number (PIN) that must be entered on the Bluetooth device in order for the pairing process to be successful. There are also some device-specific actions that must take place. For additional information on the pairing process, refer to the Owner's Literature.

This pinpoint test is intended to diagnose the following

1. Incompatible Bluetooth device
2. Customer error
3. Customer Bluetooth device
4. APIM

The Universal Serial Bus (USB) port is connected to the Accessory Protocol Interface Module (APIM) through the USB cable. The USB port can be used to play audio files or upload software from mass storage devices, or for connecting a media device.

If supported by the user device, the USB can provide charging. Because of this feature, when a USB device is plugged into the USB port, the SYNC system does not automatically switch to the device.

The USB cable and port are not serviceable separately.

1. DTC B 1252:04 (USB Port: System Internal Failure) - sets when the APIM (V2) detects an over-temperature condition in the USB circuit. This can be caused by a fault in the USB cable and port, or by the customer USB device.
2. DTC B1252:11 (USB Port: Circuit Short to Ground) - sets when the APIM (V2) detects an over-current condition in the USB circuit. This can be caused by a fault in the USB cable and port, or by the customer USB device.
3. DTC U261C (USB #1 Device Error) - sets when the APIM (VI) detects an over-current or over-temperature condition in the USB circuit. This can be caused by a fault in the USB cable and port, or by the customer USB device.

This pinpoint test is intended to diagnose the following

1. Customer USB device
2. USB cable and port
3. APIM

The Accessory Protocol Interface Module (APIM) sends left and right channel analog audio signals to the Audio Control Module (ACM). The signals include inputs from the Universal Serial Bus (USB) port, the audio input jack, and a Bluetooth media device.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. APIM
3. ACM

The Text-To-Speech (TTS) and voice prompt features speak certain text information and interaction requests in order to minimize driver distraction by having to look at the audio system display while driving. The ring tone alerts the driver to an incoming call.

Audible prompts can range from a simple tone to more elaborate spoken text, based on the customer setting. When interaction mode is set to standard, detailed guidance is provided. When interaction mode is set to advanced, most prompts are tones only and minimal audible guidance is provided. Refer to the Owner's Literature for further information on voice interaction.

The audio signals for the TTS and voice prompt features, the ring tones, and audio from the outside device during a phone call, are sent from the Accessory Protocol Interface Module (APIM) to the Audio Control Module (ACM) through circuits VMN14 (WH/VT) and RMN14 (GY/BN).

This pinpoint test is intended to diagnose the following

1. Customer setting
2. Wiring, terminals or connectors
3. APIM
4. ACM

Several audio system modules receive network messages from the Smart Junction Box (SJB) via the Medium Speed Controller Area Network (MS-CAN). The following information is included in the messages

1. Ignition switch position
2. Illumination dimmer control
3. Accessory delay status

As more than one module receives each of these messages, all modules receiving a particular message should exhibit a symptom if the message is missing.

1. DTC U0140 (Lost Communication With Body Control Module (GEM)) - set by the non-navigation Audio Control Module (ACM), the Front Controls Interface Module (FCIM) (vehicles without navigation), and the Front Display Interface Module (FDIM) when network messages are missing from the SJB for greater than 5 seconds with the ignition in RUN.
2. DTC U0140:00 (Lost Communication With Body Control Module: No Sub Type Information) - set by the navigation ACM or the Accessory Protocol Interface Module (APIM) (V2 only) when network messages are missing from the SJB for greater than 5 seconds with the ignition in RUN.

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. Audio system concern
3. SJB

1. DTC B1318 (Battery Voltage Low) - set by the non-navigation Audio Control Module (ACM) when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.
2. DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold) - set by the navigation ACM when the supply voltage falls below 10 volts for at least 10 seconds during normal operation, or for greater than 250 milliseconds during the self-test.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. High circuit resistance
3. ACM

1. DTC U3003:17 (Battery Voltage: Circuit Voltage Above Threshold) - set by the Audio Control Module (ACM) when the supply voltage is greater than 15.8 volts for more than 250 milliseconds during normal operation or the self-test.

This pinpoint test is intended to diagnose the following

1. Charging system concern
2. ACM

1. DTC B1318 (Battery Voltage Low) - set by the Front Controls Interface Module (FCIM) when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. High circuit resistance
3. FCIM

1. DTC B1318 (Battery Voltage Low) - set by the Front Display Interface Module (FDIM) when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. High circuit resistance
3. FDIM

1. DTC B1317 (Battery Voltage High) - set by the Accessory Protocol Interface Module (APIM) (VI) when the supply voltage is greater than 15.8 volts for more than 250 milliseconds during normal operation.
2. DTC U3003:17 (Battery Voltage: Circuit Voltage Above Threshold) - set by the APIM (V2) when the supply voltage is greater than 15.8 volts for more than 250 milliseconds during normal operation.

This pinpoint test is intended to diagnose the following

1. Charging system concern
2. APIM

1. DTC B1318 (Battery Voltage Low) - set by the Accessory Protocol Interface Module (APIM) (VI) when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.
2. DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold) - set by the APIM (V2) when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. High circuit resistance
3. APIM

1. DTC B1318 (Battery Voltage Low) - set by the Satellite Digital Audio Receiver System (SDARS) module when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. High circuit resistance
3. SDARS module

The Accessory Protocol Interface Module (APIM) (V2 only) receives network messages from the PCM via the High Speed Controller Area Network (HS-CAN). These messages include the odometer reading and the fuel level.

As other modules outside of the audio system also receive these messages, all modules receiving a particular message should exhibit a symptom if the message is missing.

1. DTC U0100:00 (Lost Communication With ECM/PCM "A": No Sub Type Information) - set by the APIM when it is missing messages from the PCM over the HS-CAN for greater than 5 seconds with the ignition in the RUN position.

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. PCM

The Accessory Protocol Interface Module (APIM) (V2 only) receives the air bag deployment notification message from the Restraints Control Module (RCM) via the High Speed Controller Area Network (HS-CAN). The APIM uses this message to activate the emergency call system.

As other modules outside of the audio system also receive this message, all modules receiving it should exhibit a symptom if the message is missing.

1. DTC U0151:00 (Lost Communication With Restraints Control Module: No Sub Type Information) - set by the APIM when it is missing the air bag deployment notification message from the RCM over the HS-CAN for greater than 5 seconds with the ignition in the RUN position.

This pinpoint test is intended to diagnose the following

1. Communication network concern
2. Restraints system concern