B276C-2B
B276C-2B-RIGHT HOOD HINGE PEDESTRIAN PROTECTION SQUIB - WIRES SHORTED TOGETHER
Special Tools:
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
For description of the Electronic Pedestrian Protection Module (EPPM) Electronic Pedestrian Protection Hood Hinge Actuator - Description. For operation of the EPPM Electronic Pedestrian Protection Module - Operation. When powered, the EPPM sends a test current to the Electronic Pedestrian Protection actuator squibs to verify the integrity of the squib and the wiring. Use of the Supplemental Restraints System (8443A) in the tests below substitutes a suspect EPPM actuator squib with a known good component. The use of the (8443-25) provides a test point, as well as a method for opening the shorting bar connections within the harness connector. The EPPM is powered by a Ignition Run/Start (F943) control output circuit through the 32 pin connector side of the 56 way EPPM module connector. The 32 pin connector side of the 56 way EPPM module connector provides ground.
- When Monitored:
The EPPM sends out a 40mA diagnostic current on each squib voltage supply circuit at power up and every 200ms thereafter while the ignition is in on.
- Set Condition:
The EPPM will set this DTC if it detects low resistance between the EPPM Squib 2 circuits. The DTC will set when the EPPM squib 2 circuits become shorted together for more than 2.6 seconds. The DTC will go from active to stored when the module sees a recovery from the shorted together for more than 2.6 seconds.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. . EPPM System Pre-Diagnostic Procedure
1. DETERMINE ACTIVE OR STORED DTC
NOTE: Make sure that the battery is fully charged.
NOTE: The scan tool, (8443A), and DVOM are required to perform the following test.
1. Turn the ignition on.
Select ACTIVE or STORED DTC:
ACTIVE DTC
- Go To 2
STORED DTC
- Go To 4
2. CHECK FOR SHORTED SQUIB CIRCUITS IN THE EPPM SQUIB 2 CIRCUITS
WARNING: Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
1. Disconnect the EPPM squib harness connector.
NOTE: Check connectors - Clean and repair as necessary.
2. Connect the (8443A) and the (8443-10) to the Electronic Pedestrian Protection Hood Hinge Actuator harness connector.If equipped with the keyless ignition, use this ignition on warning.
WARNING: Disconnect the 12-volt battery wait two minutes before proceeding, remove the EPPM fuse, connect the 12-volt battery, wait two minutes before proceeding. Cycle the ignition to the On position, then reconnect the EPPM fuse. Wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
If equipped with the standard key ignition, use this ignition on warning.
WARNING: Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
3. With the scan tool, read the active EPPM DTCs.
Does the scan tool display: B276C-2B-RIGHT HOOD HINGE PEDESTRIAN PROTECTION SQUIB - WIRES SHORTED TOGETHER - DTC?
Yes
- Go To 3
No
- Replace the Electronic Pedestrian Protection Hood Hinge Actuator. Electronic Pedestrian Protection Hood Hinge Actuator - Removal.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Pre-Diagnostic Procedure
3. CHECK THE (R179) EPPM SQUIB 2 LINE 1 CIRCUIT FOR A SHORT TO THE (R178) EPPM SQUIB 2 LINE 2 CIRCUIT
WARNING: Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
1. Disconnect the (8443A) and the (8443-10) from the Electronic Pedestrian Protection Hood Hinge Actuator Squib harness connectors.
2. Disconnect the EPPM harness connectors.
NOTE: Check connectors - Clean and repair as necessary.
3. Connect the (8443-25) to the EPPM connectors.
4. Measure the resistance between the (R179) EPPM Squib 2 line 1 circuit cavity 19 of the 24way side and the (R178) EPPM Squib 2 line 2 circuit cavity 20 of the 24way side at the (8443-25).
Is the resistance below 1.24 - 1.71 Ohms?
Yes
- Repair the (R179) EPPM Squib 2 line 1 circuit for a short to the (R178) EPPM Squib 2 line 2 circuit.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Pre-Diagnostic Procedure
No
- WARNING: If the Electronic Pedestrian Protection Module (EPPM) is dropped at any time, it must be replaced. Failure to take the proper precautions can result in accidental actuator deployment. Failure to follow these instructions may result in possible serious or fatal injury.
- Replace the EPPM. Electronic Pedestrian Protection Module - Removal.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Pre-Diagnostic Procedure
4. CHECKING STORED OR INTERMITTENT CODES
NOTE: Diagnose and repair all active codes before diagnosing stored codes. Refer to the list of EPPM system diagnostic procedures.
1. With the scan tool, record and erase all EPPM System Module DTCs.
WARNING: Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
2. Using the wiring diagram/schematic as a guide, inspect the related wiring and connectors for chafed, pierced, pinched, and partially broken wires, and for broken, bent, pushed out, corroded, and contaminated terminals. Repair as necessary.
3. Reconnect all disconnected components and harness connectors. If equipped with the keyless ignition, use this ignition on warning for EPPM.
WARNING: Disconnect the 12-volt battery wait two minutes before proceeding, remove the EPPM fuse, connect the 12-volt battery, wait two minutes before proceeding. Cycle the ignition to the On position, then reconnect the EPPM fuse. Wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
If equipped with the standard key ignition, use this ignition on warning.
WARNING: Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
4. With the scan tool, monitor for active codes while performing the following:
- Wiggle the wiring harness and connectors of the related EPPM circuit.
- Continue the test until either a code becomes active or the problem area is isolated.
5. In the previous steps you have attempted to recreate the conditions responsible for setting the DTC in question / causing the intermittent condition.
Are any ACTIVE DTCs present?
Yes
- Select the appropriate diagnostic procedure.
No
- No problem found at this time. Erase all codes before returning the vehicle to the customer.