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Home >> Chevrolet >> 2024 >> Tahoe Commercial, 4WD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission - 10L80 (MHS MHU MQC) - Diagnostic Information And Procedures (1 Of 2) >> Diagnostic Information and Procedures >> DTC P0658, P0659, P2812, P2814, P2815, P281B, P281D, or P281E >> Circuit/System Testing

Circuit/System Testing

  1. Ignition/Vehicle - Off
    2. NOTE:

    When the following connector is disconnected, the ignition cannot be turned off due to lack of a valid park input to the TCM. If the ignition needs to be turned off, the connector will need to be reconnected.

  2. Disconnect the electrical connector: X1@T12 Automatic Transmission
  3. Connect a test lamp between the test points: Control circuit terminal 11@Component harness & Ground
  4. Ignition - On/Vehicle - In Service Mode
    5. NOTE:

    If unable to perform the scan tool control function due to Device Limits Exceeded and/or DTC Present, jumper the component B14A circuits between the component T12 connector and the X1 harness connector.

    • Connect a 3 A fused jumper wire between the test points: 9 V Reference circuit terminal 7 X1 (harness side) & 9 V Reference circuit terminal 7 X1 (component side)
    • Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 4 X1 (harness side) & Signal circuit terminal 4 X1 (component side)
  5. Perform the scan tool control function: High Side Driver Command - On and Off

    Verify the test lamp turns On and Off.

    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Test for infinite resistance between the test points: Control circuit terminal 11 @ 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: Control circuit terminal 11 @ Component harness & The other end of the circuit
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component: K71 Transmission Control Module
    • If the test lamp is always On 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Ignition - On/Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 11 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component: K71 Transmission Control Module
    • Go to next step: If the test lamp turns On and Off 
  6. Verify DTC P0658, P0659 is not set.
    • If the DTC is set 

      Refer to step 9

    • Go to next step: If the DTC is not set 
  7. Connect a test lamp between the test points:
    • {P2812, P2814, P2815} Control circuit terminal 24 @ Component harness & Control circuit terminal 11 @ Component harness
    • {P281B, P281D, P281E} Control circuit terminal 25 @ Component harness & Control circuit terminal 11 @ Component harness
  8. Perform the scan tool control function: Transmission Control Solenoid Valve 7, 8 - On and Off

    Verify the test lamp turns On and changes brightness.

    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Test for less than 2 ohms between the test points:
      • {P2812, P2814, P2815} Control circuit terminal 24 @ Component harness & The other end of the circuit
      • {P281B, P281D, P281E} Control circuit terminal 25 @ Component harness & The other end of the circuit
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • Go to next step: If less than 2 ohms
    4. Ignition - On/Vehicle - In Service Mode
    5. Test for less than 1 V between the test points:
      • {P2812, P2814, P2815} Control circuit terminal 24 @ Component harness & Ground
      • {P281B, P281D, P281E} Control circuit terminal 25 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component: K71 Transmission Control Module
    • If the test lamp is always On 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Test for infinite resistance between the test points:
      • {P2812, P2814, P2815} Control circuit terminal 24 @ Component harness & Ground
      • {P281B, P281D, P281E} Control circuit terminal 25 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: K71 Transmission Control Module
    • Go to next step: If the test lamp turns On and changes brightness 
  9. Connect the electrical connector: X1@T12 Automatic Transmission
  10. Remove the component:
    • Transmission Fluid Pan
    • G5 Automatic Transmission Auxiliary Fluid Pump
  11. Disconnect the electrical connector: X176
  12. Connect a test lamp between the test points:
    • {P0658, P0659} Control circuit terminal 4 @ Component harness & Ground
    • {P2812, P2814, P2815} Control circuit terminal 2 @ Component harness & Control circuit terminal 4 @ Component harness
    • {P281B, P281D, P281E} Control circuit terminal 3 @ Component harness & Control circuit terminal 4 @ Component harness
  13. Perform the scan tool control function:
    • {P0658, P0659} High Side Driver - On and Off
    • {P2812, P2814, P2815, P281B, P281D, P281E} Transmission Control Solenoid Valve 7, 8 - On and Off
      • Verify the test lamp turns On and changes brightness.
    • If the test lamp is always Off 

      Replace the component: Automatic Transmission Wiring Harness - (Pass-Thru)

    • Go to next step: If the test lamp turns On and changes brightness 
  14. Connect the electrical connector: X176
  15. Disconnect the electrical connector: X177
  16. Connect a test lamp between the test points:
    • {P0658, P0659} Control circuit terminal 1 @ Component harness & Ground
    • {P2812, P2814, P2815} Control circuit terminal 2 @ Component harness & Control circuit terminal 1 @ Component harness
    • {P281B, P281D, P281E} Control circuit terminal 3 @ Component harness & Control circuit terminal 1 @ Component harness
  17. Perform the scan tool control function:
    • {P0658, P0659} High Side Driver - On and Off
    • {P2812, P2814, P2815, P281B, P281D, P281E} Transmission Control Solenoid Valve 7, 8 - On and Off
      • Verify the test lamp turns On and changes brightness.
    • If the test lamp is always Off 

      Replace the component: Automatic Transmission Wiring Harness - (Main/Solenoid)

    • Go to next step: If the test lamp turns On and changes brightness 
  18. Connect the electrical connector: X177
  19. Disconnect the appropriate electrical connector: Q77 Transmission Control Solenoid Valve
  20. Connect a test lamp between the test points: Control circuit terminal 2 @ Component harness & Control circuit terminal 1 @ Component harness
  21. Perform the scan tool control function: Transmission Control Solenoid Valve 7, 8 - On and Off

    Verify the test lamp turns On and changes brightness.

    • If the test lamp is always Off 

      Replace the component: Automatic Transmission Wiring Harness - (Jumper)

    • Go to next step: If the test lamp turns On and changes brightness 
  22. Test or replace the component: Q77 Transmission Control Solenoid Valve
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