LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2024 >> Tahoe Commercial, 4WD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission - 10L80 (MHS MHU MQC) - Diagnostic Information And Procedures (2 Of 2) >> Diagnostic Information and Procedures >> DTC P17F5-P17F7 or P17FA-P17FC >> 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. Ignition - On/Vehicle - In Service Mode
  4. Test for 8.6 to 9.2 V between the test points: 9 V Reference circuit terminal 7@T12 Automatic Transmission (harness side) & Ground
    • If less than 8.6 V 
    1. Disconnect the electrical connector: K71 Transmission Control Module
    2. Test for infinite resistance between the test points: 9 V Reference circuit terminal 7@T12 Automatic Transmission (harness side) & 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 ohms between the test points: 9 V Reference circuit terminal 7@T12 Automatic Transmission (harness side) & 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 greater than 9.2 V 
    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: 9 V Reference circuit terminal 7@T12 Automatic Transmission (harness side) & 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 between 8.6 and 9.2 V 
  5. Verify the scan tool parameter:
    • {P17F5, P17F6, P17F7} Transmission Park Valve Position Sensor = Less than 0.4 V
    • {P17FA, P17FB, P17FC} Transmission Park Valve Position Sensor 2 = Less than 0.4 V
    • If 0.4 V or greater 
    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 0.4 V between the test points:
      • {P17F5, P17F6, P17F7} Signal circuit terminal 5@T12 Automatic Transmission (harness side) & Ground
      • {P17FA, P17FB, P17FC} Signal circuit terminal 6@T12 Automatic Transmission (harness side) & Ground
      • If 0.4 V or greater - Repair the short to voltage on the circuit.
      • If less than 0.4 V - Replace the component: K71 Transmission Control Module
    • Go to next step: If less than 0.4 V 
  6. Connect a 3 A fused jumper wire between the test points:
    • {P17F5, P17F6, P17F7} Signal circuit terminal 5 & 9 V Reference circuit terminal 7
    • {P17FA, P17FB, P17FC} Signal circuit terminal 6 & 9 V Reference circuit terminal 7
  7. Verify the scan tool parameter:
    • {P17F5, P17F6, P17F7} Transmission Park Valve Position Sensor = Greater than 4.8 V
    • {P17FA, P17FB, P17FC} Transmission Park Valve Position Sensor 2 = Greater than 4.8 V
    • If less than 4.8 V 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Test for infinite resistance between the test points:
      • {P17F5, P17F6, P17F7} Signal circuit terminal 5@Component harness & Ground
      • {P17FA, P17FB, P17FC} Signal circuit terminal 6@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:
      • {P17F5, P17F6, P17F7} Signal circuit terminal 5@Component harness & The other end of the circuit@Control module harness
      • {P17FA, P17FB, P17FC} Signal circuit terminal 6@Component harness & 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: K71 Transmission Control Module
    • Go to next step: If greater than 4.8 V 
  8. Ignition/Vehicle - Off & Remove - Jumper wire(s)
  9. Remove the component: Automatic Transmission Fluid Pan
  10. Connect the electrical connector: X1@T12 Automatic Transmission
  11. Disconnect the electrical connector: B316 Transmission Park Valve Position Switch
  12. Ignition - On/Vehicle - In Service Mode
  13. Verify the scan tool parameter:
    • {P17F5, P17F6, P17F7} Transmission Park Valve Position Sensor = Less than 0.4 V
    • {P17FA, P17FB, P17FC} Transmission Park Valve Position Sensor 2 = Less than 0.4 V
    • If 0.4 V or greater 

      Replace the component: Automatic Transmission Wiring Harness

  14. Test for 8.6 to 9.2 V between the test points: 9 V Reference circuit terminal 2 & Ground
    • If not between 8.6 and 9.2 V 

      Replace the component: Automatic Transmission Wiring Harness

    • Go to next step: If between 8.6 and 9.2 V 
  15. Connect a 3 A fused jumper wire between the test points:
    • {P17F5, P17F6, P17F7} Signal circuit terminal 3 & 9 V Reference circuit terminal 2
    • {P17FA, P17FB, P17FC} Signal circuit terminal 4 & 9 V Reference circuit terminal 2
  16. Verify the scan tool parameter:
    • {P17F5, P17F6, P17F7} Transmission Park Valve Position Sensor = Greater than 4.8 V
    • {P17FA, P17FB, P17FC} Transmission Park Valve Position Sensor 2 = Greater than 4.8 V
    • If less than 4.8 V 

      Replace the component: Automatic Transmission Wiring Harness

    • Go to next step: If 4.8 V or greater 
  17. Test or replace the component: B316 Transmission Park Valve Position Switch
scientia non olet · About LEMON Manuals