Diagnostic Starting Point - Ultrasonic Rear Parking Assist
Begin the system diagnosis by reviewing the system Description and Operation. Refer to Object Detection Description and Operation . Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Ultrasonic Rear Parking Assist in order to identify the correct procedure for diagnosing the system and where the procedure is located.
Diagnostic Trouble Code (DTC) Displaying
This vehicle is equipped with an on-board diagnostic display feature capable of displaying diagnostic trouble codes using the 3 indicators on the rear parking assist display. After the bulb check has been completed, the red outside indicator flashes to indicate a malfunction with the system. The module disables operation of the URPA system under this condition.
In order to enter the diagnostic mode, complete the following actions
- With the ignition turned OFF short the rear parking assist diagnostic connector to ground while the vehicle is in PARK. Refer to «Object Detection Component Views»(ref-241696-S40727142182006081100000) for the location of the rear parking assist diagnostic connector.
- Turn the ignition ON.
- Place foot on the brake.
- Shift the vehicle into REVERSE within 5 seconds. If the vehicle is not shifted into reverse within 5 seconds after turning the ignition ON, the diagnostic mode will still be initiated. However, a reverse input wiring fault will be registered as sequence #7 as shown in the Diagnostic Indicator table below. Refer to «Diagnostic Trouble Code (DTC) Clearing»(ref-241696-S06129490182006081100000) for the specific steps on how to clear diagnostic trouble codes. After the reverse input wiring code is cleared, repeat the diagnostic trouble code displaying steps in order to enter the diagnostic mode.
When the diagnostic mode is first entered, the rear parking assist display displays the amber outside indicator and the red outside indicator. Then the indicators on the rear parking assist display will display one or more of the sequences in the table below to indicate where the fault exists within the rear parking assist system. Refer to Diagnostic Trouble Code (DTC) Clearing for the specific steps on how to clear diagnostic trouble codes.
| # | State/Fault Location | Amber Outside | Amber Middle | Red Outside | Flashing |
|---|---|---|---|---|---|
| 1 | Start of Diagnostics | X | X | ||
| 2 | RR Corner Object Sensor and Wiring | X | |||
| 3 | RR Middle Object Sensor and Wiring | X | X | ||
| 4 | LR Middle Object Sensor and Wiring | X | X | ||
| 5 | LR Corner Object Sensor and Wiring | X | |||
| 6 | Chime Warning Wiring | X | |||
| 7 | Reverse Input Wiring | X | X | ||
| 8 | IMPORTANT: This diagnostic pattern sets for an open sensor supply voltage circuit and sensor low reference circuit. Sensor Supply Voltage Circuit and Sensor Low Reference Circuit | X | X | X | X Flashes in the following sequence: Amber Outside Amber Outside and Amber Middle Amber Middle and Red Outside Red Outside |
| 9 | IMPORTANT: This diagnostic pattern sets for a short to ground in the sensor supply voltage circuit. Sensor Supply Voltage Circuit | X | X | X |
| IMPORTANT |
|---|
| This diagnostic pattern sets for an open sensor supply voltage circuit and sensor low reference circuit. |
| IMPORTANT |
|---|
| This diagnostic pattern sets for a short to ground in the sensor supply voltage circuit. |
Diagnostic Indicators
Diagnostic Trouble Code (DTC) Clearing
The rear parking assist diagnostic sequences may be cleared in one of the following ways
Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the system. Refer to «Checking Aftermarket Accessories»(ref-241671-S33907418562006081100000) in Wiring Systems.
- Inspect the easily accessible or visible system components for obvious damage or for conditions which could cause the symptom.
- Make sure the rear parking assist sensors located on the vehicle rear bumper are clear. Remove any snow, mud or ice that is blocking the sensors.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom
- «Rear Parking Assist Malfunction»(ref-241696-S31203656882006081100000)
- «Rear Parking Assist Inoperative - Red Indicator Flashes»(ref-241696-S04082483782006081100000)
Diagnostic Aids
Before performing this procedure, ensure that the following conditions are met
- The vehicle park brake is SET.
- The rear parking assist (RPA) disable switch is ON.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Object Detection Schematics | ||||
| 1 | Did you review the operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Ultrasonic Rear Parking Assist | |
| 2 | Turn the ignition ON. Place foot on the BRAKE. Shift the vehicle into REVERSE. Do all of the 3 display indicators illuminate for 2 seconds and then turn off? | Go to Step 3 | Go to Step 4 | |
| 3 | Shift the vehicle into PARK. Turn the ignition OFF. Turn the rear parking assist (RPA) switch to the OFF position. Turn the ignition ON. Place foot on the BRAKE. Shift the vehicle into REVERSE. Do all 3 display indicators illuminate for 2 seconds and then turn off? | Go to Step 14 | Go to Testing for Intermittent Conditions and Poor Connections | |
| 4 | Does the red indicator flash? | Go to Rear Parking Assist Inoperative - Red Indicator Flashes | Go to Step 5 | |
| 5 | Do all of the indicators but one indicator illuminate? | Go to Step 7 | Go to Step 6 | |
| 6 | Does any indicator remain on? | Go to Step 8 | Go to Step 11 | |
| 7 | Connect a test lamp between the control circuit of the inoperative indicator at the module connector and a good ground. Does the test lamp illuminate? | Go to Step 21 | Go to Step 9 | |
| 8 | Turn the ignition OFF. Disconnect the rear parking assist display. Turn the ignition ON. Connect a test lamp between the rear parking assist display supply voltage circuit and the malfunctioning indicator control circuit. Does the test lamp illuminate? | Go to Step 10 | Go to Step 20 | |
| 9 | Test the control circuit of the inoperative indicator for an open, a short to battery voltage or for a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 20 | |
| 10 | Test the control circuit of the inoperative indicator for a short to ground. Refer to Circuit Testing and. Did you find and correct the condition? | Go to Step 26 | Go to Step 21 | |
| 11 | Test the rear object sensor control module ground circuit for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 12 | |
| 12 | Test the rear object sensor control module ignition 1 voltage circuit for an open and for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 13 | |
| 13 | Test the backup lamp supply voltage circuit for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 16 | |
| 14 | Turn the ignition OFF. Disconnect the RPA switch. Connect a 3-amp fused jumper wire between the RPA switch signal circuit and a good ground. Turn the ignition ON. Place foot on BRAKE. Shift the vehicle into REVERSE. Do all of the 3 display indicators illuminate for 2 seconds and then turn off? | Go to Step 15 | Go to Step 22 | |
| 15 | Test the RPA switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 21 | |
| 16 | Turn the ignition OFF. Disconnect the RPA switch. Turn the ignition ON. Place foot on BRAKE. Shift the vehicle into REVERSE. Do all of the 3 display indicators illuminate for 2 seconds and then turn off? | Go to Step 22 | Go to Step 17 | |
| 17 | Test the RPA switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 18 | |
| 18 | Turn the ignition OFF. Disconnect the rear parking assist display. Turn the ignition ON. Connect a test lamp between the rear parking assist display supply voltage circuit and a good ground. Does the test lamp illuminate? | Go to Step 20 | Go to Step 19 | |
| 19 | Test the rear parking assist display supply voltage circuit for an open and for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 21 | |
| 20 | Inspect for poor connections at the harness connector of the rear parking assist display. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 24 | |
| 21 | Inspect for poor connections at the harness connector of the rear object sensor control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs s. Did you find and correct the condition? | Go to Step 26 | Go to Step 25 | |
| 22 | Inspect for poor connections at the harness connector of the RPA switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 26 | Go to Step 23 | |
| 23 | Replace the RPA switch. Refer to Power Sliding Door (PSD) On/Off-Open/Close Overhead Switch Replacement . Did you complete the replacement? | Go to Step 26 | ||
| 24 | Replace the rear parking assist display. Refer to Information Center Telltale Assembly Replacement . Did you complete the replacement? | Go to Step 26 | ||
| 25 | Replace the rear object sensor control module. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 26 | ||
| 26 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 | |
Rear Parking Assist Malfunction
Before performing this procedure, ensure that the following conditions are met
- The vehicle park brake is SET.
- The rear parking assist (RPA) disable switch is ON.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Object Detection Schematics | ||||
| 1 | Did you review the operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Ultrasonic Rear Parking Assist | |
| 2 | Turn the ignition ON. Place foot on the BRAKE. Shift the vehicle into REVERSE. Does the red indicator continue to flash after the bulb check? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections | |
| 3 | Turn the ignition OFF. Remove all objects at least 2 meters from the rear bumper. Enter the diagnostic mode. Refer to Diagnostic Trouble Code (DTC) Displaying for more information. Does diagnostic indicator pattern #1 ( Diagnostic Trouble Code (DTC) Displaying ) appear as shown in the diagnostic indicator table when you enter diagnostics? | Go to Step 4 | Go to Step 14 | |
| 4 | Does diagnostic indicator pattern #2, 3, 4 or 5 ( Diagnostic Trouble Code (DTC) Displaying ) appear as shown in the diagnostic indicator table? | Go to Step 9 | Go to Step 5 | |
| 5 | Does diagnostic indicator pattern #6 ( Diagnostic Trouble Code (DTC) Displaying ) appear as shown in the diagnostic indicator table? | Go to Step 10 | Go to Step 6 | |
| 6 | Does diagnostic indicator pattern #7 ( Diagnostic Trouble Code (DTC) Displaying ) appear as shown in the diagnostic indicator table? | Go to Diagnostic Trouble Code (DTC) Displaying and to Diagnostic Trouble Code (DTC) Clearing | Go to Step 7 | |
| 7 | Does diagnostic indicator pattern #8 ( Diagnostic Trouble Code (DTC) Displaying ) appear as shown in the diagnostic indicator table? | Go to Step 8 | Go to Step 17 | |
| 8 | Turn the ignition OFF. Disconnect only ONE rear object sensor. Perform the following actions after a rear object sensor is disconnected: Enter the diagnostic mode to determine if the diagnostic indicator pattern #8 will still be displayed. When the sensor causing the short to ground is disconnected, the diagnostic indicator pattern #8 will not be displayed. The diagnostic indicator pattern displayed will be any one of the diagnostic indicator patterns #2, #3, #4 and #5. Refer to Diagnostic Trouble Code (DTC) Displaying for more information on how to enter the diagnostic mode. Reconnect the rear object sensor when it is determined the sensor is not source of the short to ground. Clear the diagnostic trouble code (DTC). Refer to Diagnostic Trouble Code (DTC) Clearing on how to clear the diagnostic trouble codes. Repeat the above process for all rear object sensors to determine if the sensors are the source of the short to ground. Does diagnostic indicator pattern #8 ( Diagnostic Trouble Code (DTC) Displaying ) still appear as shown in the diagnostic indicator table? | Go to Step 15 | Go to Step 16 | |
| 9 | Turn the ignition OFF. Connect the DMM between the signal circuit of the inoperative rear object sensor and the low reference circuit of the rear object sensor at the rear object sensor control module with the harness connected to the module. Turn the ignition ON. Place foot on BRAKE. Shift the vehicle into REVERSE. Measure the voltage between the signal circuit of the inoperative rear object sensor and the low reference circuit of the rear object sensor. Does the voltage measure greater than the specified value? | 7 V | Go to Step 17 | Go to Step 11 |
| 10 | Turn the ignition OFF. Disconnect the rear object sensor control module connector. Measure the voltage between the rear parking assist chime signal circuit and a good ground. Does the voltage measure greater than the specified value? | 9.5 V | Go to Step 17 | Go to Step 13 |
| 11 | Test the signal circuit of the inoperative rear object sensor for an open, for a short to ground and for a short to B+. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 12 | |
| 12 | Test the supply voltage circuit and the low reference circuit of the inoperative rear object sensor for an open between S428 or S429 and the rear object sensor. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 16 | |
| 13 | Test the rear parking assist chime signal circuit for an open and for a short to ground. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 18 | |
| 14 | Test the rear parking assist diagnostic circuit for an open and for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 17 | |
| 15 | Test the supply voltage circuit and the low reference circuit of the rear object sensors for an open, for a short to ground and for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 17 | |
| 16 | Inspect for poor connections at the harness connector of the rear object sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 19 | |
| 17 | Inspect for poor connections at the harness connector of the rear object sensor control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 20 | |
| 18 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 22 | Go to Step 21 | |
| 19 | Replace the inoperative rear object sensor. Refer to Rear Object Sensor Replacement . Did you find and correct the condition? | Go to Step 22 | ||
| 20 | Replace the rear object sensor control module. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 22 | ||
| 21 | Replace the BCM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 22 | ||
| 22 | Clear all codes. Refer to Diagnostic Trouble Code (DTC) Clearing . Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 | |
Rear Parking Assist Inoperative - Red Indicator Flashes