GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B0958 01: Parking Aid Rear Sensor Left Corner Circuit Short to Battery

DTC B0958 06: Parking Aid Rear Sensor Left Corner Circuit Low Voltage/Open

DTC B0958 08: Parking Aid Rear Sensor Left Corner Circuit Performance - Signal Invalid

DTC B0958 21: Parking Aid Rear Sensor Left Corner Circuit Incorrect Period

DTC B0958 3A: Parking Aid Rear Sensor Left Corner Circuit Incorrect Component Installed

DTC B0959 01: Parking Aid Rear Sensor Left Middle Circuit Short to Battery

DTC B0959 06: Parking Aid Rear Sensor Left Middle Circuit Low Voltage/Open

DTC B0959 08: Parking Aid Rear Sensor Left Middle Circuit Performance - Signal Invalid

DTC B0959 21: Parking Aid Rear Sensor Left Middle Circuit Incorrect Period

DTC B0959 3A: Parking Aid Rear Sensor Left Middle Circuit Incorrect Component Installed

DTC B0960 01: Parking Aid Rear Sensor Right Middle Circuit Short to Battery

DTC B0960 06: Parking Aid Rear Sensor Right Middle Circuit Low Voltage/Open

DTC B0960 08: Parking Aid Rear Sensor Right Middle Circuit Performance - Signal Invalid

DTC B0960 21: Parking Aid Rear Sensor Right Middle Circuit Incorrect Period

DTC B0960 3A: Parking Aid Rear Sensor Right Middle Circuit Incorrect Component Installed

DTC B0961 01: Parking Aid Rear Sensor Right Corner Circuit Short to Battery

DTC B0961 06: Parking Aid Rear Sensor Right Corner Circuit Low Voltage/Open

DTC B0961 08: Parking Aid Rear Sensor Right Corner Circuit Performance - Signal Invalid

DTC B0961 21: Parking Aid Rear Sensor Right Corner Circuit Incorrect Period

DTC B0961 3A: Parking Aid Rear Sensor Right Corner Circuit Incorrect Component Installed

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

8 V Reference

B0954 06,

B0955 06,

B0956 06,

B0957 06

--

B0958 06,

B0959 06,

B0960 06,

B0961 06,

--

B138A 03

B0954 06,

B0955 06,

B0956 06,

B0957 06

--

B0958 06,

B0959 06,

B0960 06,

B0961 06,

B0954 06,

B0955 06,

B0956 06,

B0957 06

--

B0958 06,

B0959 06,

B0960 06,

B0961 06,

--

B138A 07

--

Left Rear Object Sensor Signal

B0958 06

B0958 06

B0958 01

B0958 08,

B0958 21

Left Middle Rear Object Sensor Signal

B0959 06

B0959 06

B0959 01

B0959 08,

B0959 21

Right Middle Rear Object Sensor Signal

B0960 06

B0960 06

B0960 01

B0960 08,

B0960 21

Right Rear Object Sensor Signal

B0961 06

B0961 06

B0961 01

B0961 08,

B0961 21

Low Reference

--

B0954 06,

B0955 06,

B0956 06,

B0957 06

--

B0958 06,

B0959 06,

B0960 06,

B0961 06

--

--

Circuit/System Description

The object sensors are 3-wire sensors that are used to determine the distance between the vehicle and an object of interest. The object alarm module supplies 8 V to the object sensors via the 8 V reference circuit and provides ground via the low reference circuit. The object alarm module triggers the sensors in a sequential loop. After each sensor transmits, the object alarm module uses the sensor ring received though the signal circuit to calculate the distance and position of an object.

Conditions for Running the DTC

    • Ignition ON
    • The parking assist is activated. The activation takes place through putting in the reverse gear or through operating the park assist switch.

Conditions for Setting the DTC

B0958 01, B0959 01, B0960 01, or B0961 01

The object alarm module has detected the voltage at the sensor circuit is greater than 11.5 V.

B0958 06, B0959 06, B0960 06, or B0961 06

The object alarm module has detected the voltage at the sensor circuit less than 0.5 V.

B0958 08, B0959 08, B0960 08, or B0961 08

The object alarm module has received an invalid signal.

B0958 21, B0959 21, B0960 21, or B0961 21

The object sensor determines no change in the position of an object while the vehicle is in motion.

B0958 3A, B0959 3A, B0960 3A, or B0961 3A

The object alarm module determines the wrong sensor type is installed.

Action Taken When the DTC Sets

    • The parking assist is disabled.
    • The parking assist indicator in the instrument panel cluster will be activated.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Reference Information

Schematic Reference

Object Detection Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Object Detection Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Verify that DTC B138A 03 or B138A 07 is not present.
  2. If DTC is present, refer to DTC B138A.
  3. Verify that DTC B0958 3A, B0959 3A, B0960 3A or B0961 3A is not present.
  4. If DTC is present, replace the appropriate sensor with a sensor of correct sensor type.
  5. Verify that DTC B0958 21, B0959 21, B0960 21 or B0961 21 is not present.
  6. If DTC is present, check the appropriate sensor for contamination with mud, ice or snow. If no contamination is diagnosed, replace the sensor.

Circuit/System Testing

  1. Ignition OFF for 30 s, disconnect the harness connector at the appropriate rear object sensor.
  2. Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K41 Object Alarm Module.
  4. Ignition ON, activate the parking assist, test for 7.5-9.0 V between the 8 V reference circuit terminal 1 and ground.
  5. If less than the specified range, test the 8 V reference circuit for an open/high resistance. If the circuit tests normal, replace the K41 Object Alarm Module.
  6. Ignition OFF, remove the malfunctioning object sensor and swap locations with another properly functioning rear object sensor. Connect the harness connector at both sensors.
  7. Ignition ON, verify the DTC is set for the new location in which the malfunctioning sensor is installed.
  8. If the DTC does not set for the new location, test the signal circuit terminal 3 for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the K41 Object Alarm Module.
    If the DTC sets for the new location in which the malfunctioning sensor is installed, replace the appropriate rear object sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Object Sensor Replacement
    •  Control Module References for object alarm module replacement, setup and programming