Electronic Pedestrian Protection Module (EPPM)

U0002-CAN C BUS OFF PERFORMANCE

Special Tools:






For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

When powered, the Electronic Pedestrian Protection module (EPPM) "listens" to the serial data bus for the broadcast of various serial data messages.

- When Monitored:
The EPPM checks for serial data message traffic at power up during the initialization process, and continuously through the ignition cycle. The EPPM repeats its check of Serial Data traffic every 20ms.

- Set Condition:
This DTC sets when the EPPM fails to detect serial data message traffic for more than 2 seconds. In the event the EPPM detects serial data message traffic, this DTC will immediately transition to stored status taking no longer than 1 second.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Electronic Pedestrian Protection Module - Removal.

1. DETERMINE ACTIVE OR STORED DTC

NOTE: Make sure the battery is fully charged.

1. Turn the ignition on.
2. With the scan tool, read EPPM DTCs.

Is the DTC active or stored?

ORC - ACTIVE DTC

- Go To 2

ORC - STORED DTC

- Perform the EPPM SYSTEM INTERMITTENT TEST. . EPPM System Intermittent Test

2. CHECK (D222) CAN C BUS (-) CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the appropriate harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (D222) CAN C BUS (-) circuit between the appropriate harness connector and ground.

Is there any voltage present?

Yes

- Repair the (D222) CAN C BUS (-) circuit for a short to voltage.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test

No

- Go To 3

3. CHECK (D221) CAN C BUS (+) CIRCUIT FOR A SHORT TO VOLTAGE
1. Measure the voltage of the (D221) CAN C BUS (+) circuit between the appropriate harness connector and ground.

Is there any voltage present?

Yes

- Repair the (D221) CAN C BUS (+) circuit for a short to voltage.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test

No

- Go To 4

4. CHECK (D221) CAN C BUS (+) CIRCUIT FOR AN OPEN

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 harness connectors.

NOTE: Check connectors - Clean and repair as necessary.

2. Connect the (8443-25)to the EPPM harness connectors.
3. Measure the resistance of the (D221) CAN C BUS (+) circuit between the appropriate harness connector and the (8443-25) cavity 24-1.

Is resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (D221) CAN C BUS (+) circuit for an open.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test

5. CHECK (D222) CAN C BUS (-) CIRCUIT FOR AN OPEN
1. Measure the resistance of the (D222) CAN C BUS (-) circuit between the appropriate harness connector and the (8443-25) cavity 24-2.

Is resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the (D222) CAN C BUS (-) circuit for an open.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test

6. CHECK (D221) CAN C BUS (+) CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance of the (D221) CAN C BUS (+) circuit between ground and the appropriate harness connector.

Is the resistance below 100.0 Ohms?

Yes

- Repair the (D221) CAN C BUS (+) circuit for a short to ground.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test

No

- Go To 7

7. CHECK (D222) CAN C BUS (-) CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance of the (D222) CAN C BUS (-) circuit between ground and the appropriate harness connector.

Is the resistance below 100.0 Ohms?

Yes

- Repair the (D222) CAN C BUS (-) circuit for a short to ground.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test

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 Verification Test