Shift Timing Solenoid B

Where it lives

For P078A, start at the solenoid the description names.

Check these first

• A failed shift timing solenoid B
• An open or short in the solenoid B wiring
• Corrosion at the solenoid B connector
• A restricted valve body passage
• A TCM driver fault

What to do next

1. Read shift timing solenoid B data on a scan tool
2. Test the solenoid B circuit for short or open
3. Measure the solenoid B resistance
4. Check the fluid level and condition
5. Replace the solenoid if the coil is off spec
6. Clear the code and retest

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