Buick Regal: DTC P16D7-P16D9

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 Descriptors

DTC P16D7

Sensor Bus Relay Control Circuit

DTC P16D8

Sensor Bus Relay Control Circuit Low

DTC P16D9

Sensor Bus Relay Control Circuit High

Diagnostic Fault Information

Engine Controls Ignition Relay

Circuit/System Description

There is 1 Sensor Supply Voltage Relay Feedback circuit supplied to the K111 Fuel Pump Driver Control Module from the K20 Engine Control Module.

Conditions for Running the DTC

P16D7

• The sensor bus relay is commanded ON.
• Battery supply signal voltage is less than 11 V.
• The DTC runs continuously when the above conditions are met.

P16D8

• The sensor bus relay is commanded ON.
• Battery supply signal voltage is less than 11 V.
• The DTC runs continuously when the above conditions are met.

P16D9

• The sensor bus relay is commanded OFF.
• Battery supply signal voltage is greater than 11 V.
• The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

Control Circuit=Commanded state does not match the actual state for greater than 1 s

Action Taken When the DTC Sets

DTCs P16D7, P16D8 and P16D9 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P16D7, P16D8 and P16D9 are Type B DTCs.

Diagnostic Aids

The sensor bus relay may also be labeled the sensor supply voltage relay, sensor bus relay control circuit, or sensor supply voltage feedback circuit.

Reference Information

Schematic Reference

• Engine Controls Wiring Schematics (LGX)
• Power Distribution Wiring Schematics

Connector End View Reference

Component Connector End View Index

Component View Reference

Powertrain Component Views

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Electrical Center Identification Views
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, observe the scan tool DTC information. Verify DTC P16D7, P16D8, or P16D9 is not set.

• If any of the DTCs are set

Refer to Circuit/System Testing.

• Go to next step: If none of the DTCs are set

2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

• If the DTC sets

Refer to Circuit/System Testing.

• Go to next step: If the DTC does not set

3. All OK.

Circuit/System Testing

1. Ignition/Vehicle & All vehicle systems - Off.

2. Disconnect the electrical connector:K111 Fuel Pump Driver Control Module.

3. Verify a test lamp does not turn On between the test points:Control circuit terminal 2 & B+ terminal 7.

• If the test lamp turns On

1. Remove - Test Lamp
2. Disconnect the electrical connector:X3@ Verify a test lamp does not turn On between the test points: Control circuit terminal 2 & B+ terminal 7
   • If the test lamp turns On - Repair the short to ground on the circuit.
   • Replace the component: - K20 Engine Control Module

• Go to next step: If the test lamp does not turn On

4. Ignition - On / Vehicle - In Service Mode.

5. Verify a test lamp does not turn On between the test points: Control circuit terminal 2 & Ground terminal 22.

• If the test lamp turns On

1. Remove - Test Lamp
2. Disconnect the electrical connector:X3@K20 Engine Control Module
3. Verify a test lamp does not turn On between the test points:Control circuit terminal 2 & Ground terminal 22
   • If the test lamp turns On - Repair the short to voltage on the circuit.
   • If the test lamp does not turn On - Replace the component:K20 Engine Control Module

• Go to next step: If the test lamp does not turn On

6. Verify a test lamp turns On between the test points: Control circuit terminal 2 & B+ terminal 7

• If the test lamp does not turn On

1. Disconnect the electrical connector:X3@K20 Engine Control Module
2. Test for less than 2 ohms between the test points:Control circuit terminal 2@K111 Fuel Pump Driver Control Module & Control circuit terminal 3 X3@K20 Engine Control Module
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Replace the component:K20 Engine Control Module

• Go to next step: If the test lamp turns On

7. Replace the component: - K111 Fuel Pump Driver Control Module

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Engine Wiring Harness Junction Block Replacement (LTG) or Engine Wiring Harness Junction Block Replacement (LGX).
• Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an Electrical Center)
• Control Module References for engine control module replacement, programming, and setup.

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