U11A0
U11A0-00-LOST COMMUNICATION W/CENTER-PEDESTRIAN PROTECTION SATELLITE ACCELERATION SENSOR
Special Tools:
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The pedestrian protection impact sensors perform their own self test using power supplied by the Electronic Pedestrian Protection module (EPPM) then communicate this status back to the EPPM with periodic updates. The repair of this fault condition involves verifying the integrity of the wiring between the EPPM and the sensor. For EPPM Description information Electronic Pedestrian Protection Module - Description. For EPPM Operation information Electronic Pedestrian Protection Module - Operation.
- When Monitored:
The EPPM monitors communication with the Center Pedestrian Protection Impact sensor continuously.
- Set Condition:
This DTC sets when the EPPM no longer receives notification of the status update from the center pedestrian protection satellite acceleration sensor. Once set, this DTC is latched for the entire ignition cycle. This code will set active if the loss of communication with the sensor has lasted for more then 2.5 seconds. This fault is latched for the full ignition cycle. The fault will go stored on the next key cycle upon the fault not setting for longer then 2.5 seconds.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. . EPPM System Pre-Diagnostic Procedure
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?
EPPM - ACTIVE DTC
- Go To 2
EPPM - STORED DTC
- Perform the EPPM SYSTEM INTERMITTENT TEST. . EPPM System Intermittent Test
2. CHECK FOR ADDITIONAL ACTIVE SATELLITE SENSOR DTCS
NOTE: The scan tool, (8443-25), and a DVOM are required to perform the following tests.
1. With the scan tool, read all active EPPM DTCs.
Is DTC U119E-00-LOST COMMUNICATION W/LEFT-PEDESTRIAN PROTECTION SATELLITE ACCELERATION SENSOR and U119F-00-LOST COMMUNICATION W/RIGHT-PEDESTRIAN PROTECTION SATELLITE ACCELERATION SENSOR also active?
Yes
- Go To 8
No
- Go To 3
3. CHECK (R174) CENTER PEDESTRIAN IMPACT SENSOR SIGNAL 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 Center Pedestrian Impact Sensor harness connector.
2. Disconnect the EPPM harness connectors.
NOTE: Check the connectors - Clean and repair as necessary.
3. Connect the (8443-25) to the EPPM harness connectors.
4. Measure the resistance of the (R174) Center Pedestrian Impact Sensor Signal circuit between the Center Impact Sensor harness connector to the (8443-25) connector cavity 32 - 29.
Is the resistance below 1.0 Ohm?
Yes
- Go To 4
No
- Repair or replace the (R174) Center Pedestrian Impact Sensor Signal circuit for an open. Then, Go To 4
4. CHECK (R175) CENTER PEDESTRIAN IMPACT SENSOR GROUND CIRCUIT FOR AN OPEN
1. Measure the resistance of the (R175) Center Pedestrian Impact Sensor ground circuit between the Center Front Impact Sensor harness connector and the (8443-25) connector cavity 32 - 30.
Is the resistance below 1.0 Ohm?
Yes
- Go To 5
No
- Repair or replace the (R175) Center Pedestrian Impact Sensor ground circuit for an open.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test
5. CHECK (R175) CENTER PEDESTRIAN IMPACT SENSOR GROUND CIRCUIT FOR A SHORT TO THE (R174) CENTER PEDESTRIAN IMPACT SENSOR SIGNAL CIRCUIT
1. Measure the resistance between the (R174) Center Pedestrian Impact Sensor Signal circuit cavity 2 and the (R175) Center Pedestrian Impact Sensor ground circuit cavity 1 at the Center Pedestrian Impact Sensor harness connector.
Is the resistance below 5K Ohms?
Yes
- Repair or replace the (R174) Center Pedestrian Impact Sensor Signal circuit for a short to the (R175) Center Pedestrian Impact Sensor ground circuit.
- Perform the EPPM SYSTEM VERIFICATION TEST. Electronic Pedestrian Protection Module - Removal.
No
- Go To 6
6. CHECK (R174) CENTER PEDESTRIAN IMPACT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance of the (R174) Center Pedestrian Impact Sensor Signal circuit between ground and the Center Pedestrian Impact Sensor harness connector cavity 2.
Is the resistance below 6K Ohms?
Yes
- Repair or replace the (R174) Center Pedestrian Impact Sensor Signal circuit for a short to ground.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test
No
- Go To 7
7. CHECK (R174) CENTER PEDESTRIAN IMPACT SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 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.
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.
1. Measure the voltage of the (R174) Center Pedestrian Impact Sensor Signal circuit between the Left Front Impact Sensor harness connector cavity 2 and ground.
Is there any voltage present?
Yes
- 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.
- Repair or replace the (R174) Center Pedestrian Impact Sensor Signal circuit for a short to voltage.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test
No
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test If DTC U11A0-00-LOST COMMUNICATION W/CENTER PEDESTRIAN PROTECTION SATELLITE ACCELERATION SENSOR is still active, Go To 9. Otherwise, test complete.
8. CHECK (R172) RIGHT PEDESTRIAN IMPACT SIGNAL CIRCUIT AND (R174) CENTER PEDESTRIAN IMPACT SENSOR SIGNAL CIRCUIT AND (R170) LEFT PEDESTRIAN IMPACT SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
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 Center Pedestrian Impact Sensor Signal circuit harness connector.
2. Disconnect the Right Pedestrian Impact Sensor Signal circuit harness connector.
3. Disconnect the Left Pedestrian Impact Sensor Signal circuit harness connector.
4. Disconnect the EPPM harness connectors.
NOTE: Check the connectors - Clean and repair as necessary.
5. Connect the (8443-25) to the EPPM harness connectors. 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.
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.
6. Measure the voltage of the (R174) Center Pedestrian Impact Sensor Signal circuit between the (8443-25) cavity 32 - 29 and ground.
7. Measure the voltage of the (R170) Left Pedestrian Impact Sensor Signal circuit between the (8443-25) cavity 24 - 12 and ground.
8. Measure the voltage of the (R172) Right Pedestrian Impact Sensor Signal circuit between the (8443-25) cavity 24 - 9 and ground.
Is there any voltage present?
Yes
- 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.
- Repair or replace the impact sensor circuit with voltage present for a short to voltage.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test
No
- Go To 9
9. CHECK OPERATION OF CENTER PEDESTRIAN IMPACT SENSOR
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. Replace the Center Pedestrian Impact Sensor. . Electronic Pedestrian Protection Impact Sensor - Removal
2. Reconnect the vehicle body harness to the impact sensor.
3. Remove any special tools or jumper wires and reconnect all previously disconnected components - except the Battery. 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.
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.
4. Connect the scan tool to the Data Link Connector - use the most current software available.
5. With the scan tool, erase all codes in the EPPM.
6. Perform EPPM module reset. Access the Diagnostic Procedures menu from the EPPM ECU Overview screen on the scan tool to perform this operation.
7. Wait one minute, and read active codes.
Did the active DTC U11AO-00-LOST COMMUNICATION W/CENTER PEDESTRIAN PROTECTION SATELLITE ACCELERATION SENSOR return?
Yes
- 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.
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.
- Replace the EPPM. Electronic Pedestrian Protection Module - Removal.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test
No
- Repair is complete.
- Perform the EPPM SYSTEM VERIFICATION TEST. . EPPM System Verification Test