Buick Regal: DTC P163A

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 P163A

Control Module Fuel Pressure Regulator 1 Control System Circuitry Performance

Circuit/System Description

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM) or an out of range high pressure fuel pump actuator current.

Conditions for Running the DTC

• DTC P0016, P0017, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0128, P0191, P0192, P0193, P0335, P0336, P0340, P0341, P0365, P0366, P0628, or P1682 is not set.
• The engine is running.
• The ignition voltage is greater than 11 V.
• The low side fuel pressure is greater than 250 kPa (36 psi).
• The barometric (BARO) pressure is greater than 70 kPa.
• The intake air temperature (IAT) is warmer than -20ºC (-4ºF).
• DTC P163A runs continuously when the conditions are met for greater than 500 mS.

Conditions for Setting the DTC

The ECM detects a condition with the integrated circuits of the high pressure fuel pump actuator driver module or the ECM detects that the current used to drive the high pressure fuel pump actuator is greater than 11 A or less than 0.1 A for greater than 4 s.

Action Taken When the DTC Sets

DTC P163A is a Type B DTC.

Conditions for Clearing the DTC

DTC P163A is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Wiring Schematics (LTG)

Connector End View Reference

Component Connector End View Index

Description and Operation

Fuel System Description

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• 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 Testing

1. Ignition OFF, disconnect the harness connector at the G18 High Pressure Fuel Pump.

NOTE: The DMM and test leads must be calibrated to 0 Ω in order to prevent misdiagnosis.

2. Test for 0.3 - 0.7 Ω at 20ºC (68ºF) between the high control circuit terminal 1 and the low control circuit terminal 2 on the G18 High Pressure Fuel Pump.

• If not between 0.3 - 0.7 Ω

Replace the G18 High Pressure Fuel Pump.

• Go to next step: If between 0.3 - 0.7 Ω

3. Test for infinite resistance between each terminal on the G18 High Pressure Fuel Pump and the G18 High Pressure Fuel Pump housing.

• If less than infinite resistance

Replace the G18 High Pressure Fuel Pump.

• Go to next step: If infinite resistance

4. Ignition ON, verify that a test lamp does not illuminate between the high control circuit terminal 1 and ground and the low control circuit terminal 2 and ground at the ECM side of the harness connector.

• If the test lamp illuminates

1. Ignition OFF, disconnect the harness connector at the ECM, ignition ON.
2. Test for less than 1 V between the appropriate control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K20 Engine Control Module.

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

5. Verify that a test lamp does not illuminate between the high control circuit terminal 1 and B+ and the low control circuit terminal 2 and B+.

• If the test lamp illuminates

1. Ignition OFF, disconnect the harness connector at the ECM.
2. Test for infinite resistance between the appropriate control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

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

6. Connect a 3 A fused jumper wire between the high control circuit terminal 1 and ground.

7. Verify the Fuel Pressure Regulator High Control Circuit Open Test Status transitions from Malfunction to OK and the Fuel Pressure Regulator High Control Circuit Low Voltage Test Status transitions from OK to Malfunction.

• The parameters do not change

1. Ignition OFF, disconnect the harness connector at the ECM.
2. Test for less than 2 Ω in the high control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

• Go to next step: The parameters change

8. Connect a 3 A fused jumper wire between the low control circuit terminal 2 and B+.

9. Verify the Fuel Pressure Regulator Control Circuit Open Test Status transitions from Malfunction to OK and the Fuel Pressure Regulator Control Circuit High Voltage Test Status transitions from OK to Malfunction.

• The parameters do not change

1. Ignition OFF, disconnect the harness connector at the ECM.
2. Test for less than 2 Ω in the low control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

• Go to next step: The parameters change

Go to next step: Replace the K20 Engine Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Fuel Pump Replacement
• Control Module References for engine control module replacement, setup, and programming
• Perform the Fuel Rail Pressure Relief Valve Reset procedure, if supported on the scan tool.

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