• Perform the Diagnostic System Check prior to using this diagnostic procedure:Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis:Strategy Based Diagnosis
• An overview of each diagnostic category can be found here:Diagnostic Procedure Instructions

For an overview of the component/system, refer to:Electronic Component Description

The solenoid valve directs pressurized fluid to exit the accumulator to apply the clutches for a 1st gear start, during an Auto Start event.

• Battery Voltage=Greater than 9 V
• Ignition=On
• Ignition Voltage=Greater than 9 V

Frequency the DTC runs=Continuously—After the running conditions are met—For greater than 1 s

Control circuit=Open/High Resistance—For greater than 1 s

Control circuit=Short to Ground/Open/High Resistance—For greater than 1 s

Control circuit=Short to Voltage—For greater than 1 s

DTCs listed in the DTC Descriptor category=Type B DTC

• Autostart/Autostop=Disabled
• { P171B }Transmission Adaptive Values Learn=Freeze current adapt values

DTCs listed in the DTC Descriptor category=Type B DTC

Automatic Transmission Controls Schematics

Master Electrical Component List

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Control Module References

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P0658, P0659 is not set
• If any of the DTCs are set

  Refer to:DTC P0658, P0659, P2727, P2729, P2730, P2736, P2738, P2739, P2826, P2827, P282F, or P2830

• If none of the DTCs are set
3. Perform the following action:Clear DTCs
4. Perform the scan tool control function:Transmission Accumulator Solenoid Valve»On and Off

   Verify the scan tool parameter:

• Transmission Accumulator Solenoid Valve Control Circuit High Voltage Test Status=Not RunorOK
• Transmission Accumulator Solenoid Valve Control Circuit Low Voltage Test Status=Not RunorOK
• Transmission Accumulator Solenoid Valve Control Circuit Open Test Status=Not RunorOK
• If not the specified state

  Refer to: Circuit/System Testing

• If the specified state
5. Perform the scan tool control function:Transmission Accumulator Solenoid Valve»On and Off

   Verify a click can be heard or felt at the following component(s) when the scan tool control function was commanded:

• If a click cannot be heard or felt

  Refer to: Circuit/System Testing

• If a click can be heard or felt
6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

   Verify the DTC does not set.

• If the DTC sets

  Refer to: Circuit/System Testing

• If the DTC is not set
7. All OK.

1. Ignition/Vehicle » Off
2. Disconnect the electrical connector:B280 Automatic Transmission Accumulator Solenoid Valve
3. Connect a test lamp between the test points:Control circuit terminal 1&Ground
4. Ignition » On / Vehicle » In Service Mode
5. Perform the scan tool control function:High Side Driver 1»On and Off

   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:K71 Transmission Control Module
3. Test for infinite resistance between the test points:Control circuit terminal 1@Component harness&Ground
• If less than infinite resistance » Repair the short to ground on the circuit.
• If infinite resistance
4. Test for less than 2 Ω between the test points:Control circuit terminal 1@Component harness&Terminal 33@Control module harness
• If 2 Ω or greater » Repair the open/high resistance in the circuit.
• If less than 2 Ω » Replace the component:K71 Transmission Control Module
• If the test lamp is always On
1. Ignition/Vehicle » Off & Remove » Test lamp
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 1@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 turns On and Off
6. Remove » Test Lamp
7. Ignition/Vehicle » Off
8. Disconnect the electrical connector:K71 Transmission Control Module
9. Test for less than 2 Ω between the test points:Control circuit terminal 2@Component harness&Terminal 24@Control module harness
• If 2 Ω or greater

  Repair the open/high resistance in the circuit.

• If less than 2 Ω
10. Test for infinite resistance between the test points:Control circuit terminal 2&Ground
• If less than infinite resistance

  Repair the short to ground on the circuit.

• If infinite resistance
11. Ignition » On / Vehicle » In Service Mode
12. Test for less than 1 V between the test points:Control circuit terminal 2&Ground
• If 1 V or greater

  Repair the short to voltage on the circuit.

• If less than 1 V
13. Ignition/Vehicle » Off

Note: The component's temperature should be 19 to 21°C (66 to 70°F) while testing.

14. Test for 17 to 19 Ω between the test points:Control terminal 1&Control terminal 2
• If not between 17 and 19 Ω

  Replace the component:B280 Automatic Transmission Accumulator Solenoid Valve

• If between 17 and 19 Ω
15. Test for infinite resistance between the test points:Each terminal of the component&The component's housing
• If less than infinite resistance

  Replace the component:B280 Automatic Transmission Accumulator Solenoid Valve

• If infinite resistance
16. Replace the component:K71 Transmission Control Module

Perform the Diagnostic Repair Verification after completing the repair:Diagnostic Repair Verification

• Auxiliary Fluid Accumulator Replacement—B280 Automatic Transmission Accumulator Solenoid Valve
• For control module replacement, programming, and setup refer to:Control Module References

Transmission Service Fast Learn Procedure—Perform only when the component/system is serviced.