Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC U209D 00: Battery Energy Control Module High Speed Communication Enable Circuit HighDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Wake Up Signal (circuit 5986) | U209A in SDGM or U2099 in BCM | U209A* | U209D** | -- |
* Other modules will set other DTC with this fault. ** Will set DTC U209D as current with the key OFF, and as history with the key ON. Will also likely cause a parasitic drain on battery. | ||||
Circuit/System Description
Modules connected to the LAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
2 wake up signal circuits (5986, 5985) are energized by the body control module (BCM) to activate multiple modules including the drive motor generator battery control module (BECM) when serial data is required. Wake up signal circuit (968) is energized by the serial data gateway module (SDGM) to activate the BECM immediately after the BCM energizes circuit 5986 and 5985. The BECM compares the status of both wake up circuits.
Conditions for Running the DTC
| • | The system voltage is between 9-18 volts. |
| • | Ignition key OFF. |
Conditions for Setting the DTC
The BECM receives voltage from the BCM on wake up signal circuit 5986 for 3 seconds with the ignition OFF.
Action Taken When the DTC Sets
The hybrid powertrain control module (HPCM) will set DTC U209D.
Conditions for Clearing the DTC
| • | A current DTC clears when the malfunction is no longer present, including a key ON condition when both wake up signals are energized. |
| • | A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction. |
Diagnostic Aids
| • | DTC U209D will only set as current with the ignition in the OFF position. It will become history when the ignition is turned ON. |
| • | When testing circuits to the SDGM access can be accomplished by removing the instrument panel center trim panel. Note that this procedure does not allow removal of the SDGM, only access to the connector. Refer to Instrument Panel Center Trim Panel Replacement . |
| • | Different DTCs may set in different modules along with this DTC depending on where the fault occurs and the vehicle operating conditions when the fault occurs. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Data Link Communications Description and Operation
Electrical Information Reference
Circuit/System Testing
Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.
The High Voltage Disabling procedure will perform the following tasks:| • | Identify how to disable high voltage. |
| • | Identify how to test for the presence of high voltage. |
| • | Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed. |
- Perform the High Voltage Disabling procedure.
- Ignition OFF, disconnect harness connector X1 of the BECM.
- Reconnect the 12-volt battery.
- Ignition OFF and scan tool disconnected, test for less than 1 volt between wake up signal terminal 13 and ground.
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for module replacement, setup, and programming
