Power Distribution Module: Service and Repair

SMART JUNCTION BOX (SJB)







Removal

CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to these charges, damage may result.

NOTE:
- Prior to the replacement of the smart junction box (SJB), it is necessary to upload the module configuration information to the appropriate scan tool. This information must be downloaded into the new SJB after installation.
- The tire pressure monitoring system (TPMS) functionality is integrated into the SJB. On late build vehicles only, tire pressure sensors are mounted on the wheels. Early build vehicles do not have these tire pressure sensors. Late build vehicles need to have this feature configured on and early build vehicles need to have this feature configured off. This is automatically accomplished during programmable module installation (PMI).

1. NOTE: The steps included in the SJB removal and installation procedure are critical to restoring the vehicle security and tire pressure monitoring systems to normal operation. A new SJB is delivered in a manufacturing mode with 7 pre-set DTCs. To clear the DTCs, successful configuration of the SJB must occur, followed by successful TPMS sensor training (late build vehicles only), and a successful self-test, including clearing of the DTCs. The DTCs are as follows:
- B2477 (Module Configuration Failure)
- B106D (Tire Pressure Monitor System [TPMS] Initiators Not Configured)
- B2868 (Left Front Tire Pressure Sensor Fault)
- B2869 (Right Front Tire Pressure Sensor Fault)
- B2870 (Right Rear Tire Pressure Sensor Fault)
- B2871 (Left Rear Tire Pressure Sensor Fault)
- C2780 (ECU in Manufacturer Sub-State)

NOTE: This step is necessary only if the SJB is being replaced.

Upload the module configuration information from the SJB.

2. Remove the passenger cowl side trim panel.

3. NOTE: The upper 12A581 harness SJB (B+) connector may be more easily removed after the SJB bolts are removed and the SJB can be positioned lower and away from the body in order for the connector release tangs to be accessed and pressed.

Disconnect the 7 SJB electrical connectors.

4. Remove the in-line connector push-pin from the SJB.
5. Remove the 2 bolts and the SJB.

Installation
1. Install the 2 bolts and the SJB.
- Tighten to 2 Nm (18 lb-in).

2. Install the in-line connector push-pin on the SJB.
3. Connect the 7 SJB electrical connectors.

4. NOTE: If the SJB was not replaced, this is the last step that is necessary.

Install the passenger cowl side trim panel.

5. NOTE:
- When successful, this step provides the calibration necessary for the SJB operation and clears DTCs B106D and B2477. The clearing of these DTCs indicates the calibration data has been successfully downloaded to the new SJB.
- On early build vehicles only, this step will also clear the rest of the TPMS DTCs (B2868, B2869, B2870 and B2871).

Download the SJB configuration information from the scan tool.

6. NOTE:
- This step is applicable to late build vehicles only.
- When successful, this step clears DTCs B2868, B2869, B2870 and B2871. The clearing of these DTCs indicates the SJB has recognized the tire pressure sensors during the training procedure.

Train the tire pressure sensors.

7. NOTE:
- DTC C2780 will not clear if any other DTCs are present in the SJB. When successful, this step will clear the DTC C2780.
- If the battery is disconnected, discharged or if power to the SJB is interrupted/disconnected, the instrument panel dimmer switch requires re-calibration. Rotate the instrument panel dimmer switch from the full dim position to the dome ON position. This will make sure that all displays are visible under all lighting conditions.

Carry out the SJB on-demand self-test by clearing DTCs, and then retrieving DTCs to confirm all DTCs have been cleared.