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Home >> Buick >> 2020 >> Envision Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 154 (Battery, Charging System And Starting System) >> Diagnostic Information and Procedures >> DTC P26E4-P26E6 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2020 Buick Regal TourX, 2020 Buick Regal, 2019 Buick Regal TourX, 2019 Buick Regal, and 2018 Buick Regal TourX. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Remove the component: KR27C Starter Pinion Solenoid Actuator Relay
  3. Test for less than 10 ohms between the test points: Ground circuit terminal 86 @ Relay Socket & Ground
    • If 10 ohms or greater 
    1. Disconnect - Ground
    2. Test for less than 2 ohms between the test points: Ground circuit terminal 86 @ Relay Socket & Ground
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 10 ohms 
  4. Ignition - On/Vehicle - In Service Mode
  5. Verify a test lamp turns On between the test points: B+ circuit terminal 30 & Ground
    • If the test lamp does not turn On and the circuit fuse is OK 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Test for less than 2 ohms between the test points: B+ circuit terminal 30 & Output terminal @ Fuse
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not turn On and the circuit fuse is open 
    1. Ignition OFF.
    2. Test for infinite resistance between the B+ circuit and ground.
      • Ignition/Vehicle - Off & Remove - Test lamp
      • Test for infinite resistance between the test points: B+ circuit terminal 30 & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance,
    3. Disconnect the component: M64 Starter Motor
    4. Test for infinite resistance between the test points: Control circuit terminal 87 & Ground
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M64 Starter Motor.
    • Go to next step: If the test lamp turns On 
  6. Connect a test lamp between the test points: Ground circuit terminal 86 & Control circuit terminal 85
  7. If available - Perform the scan tool control function: Starter Pinion Solenoid Actuator Relay Command - On and Off

    or

    If available - Cycle the ignition from OFF to ON. - Park Brake Applied - Clutch pedal fully pressed - Manual Transmission or - Transmission in Park - Automatic Transmission

    - Verify the test lamp turns On and Off.

    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the electrical connector: K20 Engine Control Module
    3. Test for infinite resistance between the test points: Control circuit terminal 85 @ Relay Socket & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: K20 Engine Control Module
    • If the test lamp is always On 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the electrical connector: K20 Engine Control Module
    3. Ignition - On/Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 85 @ Relay Socket & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for less than 2 ohms between the test points: Control circuit terminal 85 @ Relay Socket & The other end of the circuit @ Control module harness
      • 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 and Off 
  8. Connect a 30 A fused jumper wire between the test points: B+ circuit terminal 30 @ Relay Socket & Control circuit terminal 87 @ Relay Socket
  9. Verify the component activates: M64 Starter Motor
    • If the component does not activate 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: M64 Starter Motor
    3. Test for infinite resistance between the test points: Control circuit terminal X1 2/X1 1/X1 A @ Relay Socket & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: K20 Engine Control Module
    • Go to next step: If the component activates 
  10. Test or replace the component: KR27C Starter Pinion Solenoid Actuator Relay
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