LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2021 >> XT5 Sport >> Repair and Diagnosis >> External Pages >> Different car >> Section 838 (Automatic Transmission - 10L1000 (MGM MGU) - Diagnostic Information And Procedures (1 Of 2)) >> Diagnostic Information and Procedures >> DTC P0707, P0708, P2802, P2803, or P2805 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. 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. NOTE:

    To turn the ignition off on vehicles equipped with a push button ignition switch, the wiring harness connector must be connected to the component T12.A valid park input signal to the control module K71 is required to turn the ignition off.

  2. Disconnect the electrical connector: X1@T12 Automatic Transmission Assembly
  3. Test for less than 10 ohms between the test points: Low Reference circuit terminal 20 & Ground
    • If 10 ohms or greater 
    1. Disconnect the electrical connector: X3@K20 Engine Control Module
    2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 20@Component harness & Low Reference circuit terminal 45@ 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 less than 10 ohms 
  4. Ignition - On/Vehicle - In Service Mode
  5. Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 12 & Low Reference circuit terminal 20
    • If less than 4.8 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: X3@K20 Engine Control Module
    3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 12@Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    4. Test for less than 2 ohms between the test points: 5 V Reference circuit terminal 12@Component harness & 5 V Reference circuit terminal 47@ 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
    • If greater than 5.2 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the appropriate electrical connector: K20 Engine Control Module
    3. Ignition - On/Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: 5 V Reference circuit terminal 12@Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component: K20 Engine Control Module
    • Go to next step: If between 4.8 and 5.2 V 
  6. Verify the scan tool parameter:
    • Transmission Range Sensor 1@K71 Transmission Control Module@Transmission Data = 100%
    • Transmission Range Sensor 2@K20 Engine Control Module@Automatic Transmission Data = 100%
    • If not the specified values 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: X3@K20 Engine Control Module
    3. Disconnect the electrical connector: K71 Transmission Control Module
    4. Ignition - On/Vehicle - In Service Mode
    5. Test for less than 1 V between the test points:
      • {P0707, P0708} Signal circuit terminal 5 & Ground
      • {P2802, P2803} Signal circuit terminal 6 & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    6. Test for infinite resistance between the test points:
      • {P0707, P0708} Signal circuit terminal 5 & Ground
      • {P2802, P2803} Signal circuit terminal 6 & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • {P0707, P0708} If infinite resistance - Replace the component: K71 Transmission Control Module
      • {P2802, P2803} If infinite resistance - Replace the component: K20 Engine Control Module
    • Go to next step: If the specified values 
  7. Connect a 3 A fused jumper wire between the test points:
    • Signal circuit terminal 5 & Low Reference circuit terminal 20
    • Signal circuit terminal 6 & Low Reference circuit terminal 20
  8. Verify the scan tool parameter:
    • Transmission Range Sensor 1@K71 Transmission Control Module@Transmission Data = 0%
    • Transmission Range Sensor 2@K20 Engine Control Module@Automatic Transmission Data = 0%
    • If not the specified values 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: X3@K20 Engine Control Module
    3. Disconnect the electrical connector: X1@T12 Automatic Transmission Assembly
    4. Test for less than 2 ohms between the test points:
      • {P0707, P0708} Signal circuit terminal 5@Component harness & & Signal circuit terminal 64@K71 Transmission Control Module - Control module harness
      • {P2802, P2803} Signal circuit terminal 6@Component harness & Signal circuit terminal 55@K20 Engine Control Module - Control module harness
      • If greater than 2 ohms - Repair the open/high resistance in the circuit.Repair the open/high resistance in the circuit.
      • {P0707, P0708} If less than 2 ohms - Replace the component: K71 Transmission Control Module
      • {P2802, P2803} If less than 2 ohms - Replace the component: K20 Engine Control Module
      • Go to next step: If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for less than 2 ohms between the test points:
      • {P0707, P0708} Signal circuit terminal 5@Component harness & Signal circuit terminal 64 Control module harness
      • {P2802, P2803} Signal circuit terminal 6@Component harness & Signal circuit terminal 55 Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • {P0707, P0708} If less than 2 ohms - Replace the component: K71 Transmission Control Module
      • {P2802, P2803} If less than 2 ohms - Replace the component: K20 Engine Control Module
    • Go to next step: If the specified values 
  9. Ignition/Vehicle - Off & Remove - Jumper wire(s)
  10. Connect the electrical connector: X1 @ T12 Automatic Transmission Assembly
  11. Remove the component: Automatic Transmission Fluid Pan
  12. Disconnect the electrical connector: B303 Transmission Range Sensor
  13. Test for less than 10 ohms between the test points: Low Reference circuit terminal 1@Component harness & Ground
    • If greater than 10 ohms 

      Replace the component: Automatic Transmission Wiring Harness

    • Go to next step: If less than 10 ohms 
  14. Ignition - On/Vehicle - In Service Mode
  15. Verify the scan tool parameter:
    • Transmission Range Sensor 1@K71 Transmission Control Module@Transmission Data = 100%
    • Transmission Range Sensor 2@K71 Transmission Control Module@Automatic Transmission Data = 100%
    • = If not the specified values 

      Replace the component: Automatic Transmission Wiring Harness

    • Go to next step: If the specified values 
  16. Connect a 3 A fused jumper wire between the test points:
    • Signal circuit terminal 5 & Low Reference circuit terminal 20
    • Signal circuit terminal 6 & Low Reference circuit terminal 20
  17. Verify the scan tool parameter:
    • Transmission Range Sensor 1@K71 Transmission Control Module@Transmission Data = 0%
    • Transmission Range Sensor 2@K71 Transmission Control Module@Automatic Transmission Data = 0%
    • If not the specified values 

      Replace the component: Automatic Transmission Wiring Harness

    • Go to next step: If the specified values 
  18. Test or replace the component: B303 Transmission Range Sensor
scientia non olet · About LEMON Manuals