Shift Solenoid A Control Circuit Low
The P0973 code means the vehicle's onboard diagnostic system has detected: Shift Solenoid A Control Circuit Low. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $800 (parts and labor)
Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.
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Common Symptoms
- Check Engine Light illuminated
- Transmission stuck in one gear or limp mode
- No 1-2 upshift
- Harsh shifting when it does occur
Probable Causes (Ranked by Likelihood)
- Short to ground in shift solenoid A wiring Very High
- Faulty shift solenoid A with low resistance High
- Transmission internal wiring harness damage Moderate
- TCM output driver failure Low
Step-by-Step Diagnostic Procedure
-
Measure voltage at shift solenoid A connector
-
Check for short to ground in the solenoid control wire
-
Inspect the internal transmission wiring harness if applicable
-
Test solenoid A resistance at the transmission connector
Frequently Asked Questions
What does circuit low mean for shift solenoid A?
The voltage on the solenoid control wire is below the expected minimum, usually caused by a short to ground or an internally shorted solenoid.
Can the internal transmission harness be repaired?
Internal transmission wiring harnesses can often be replaced without a full transmission rebuild. The harness is accessible after removing the valve body.
Is P0973 more serious than P0972?
P0973 indicates a definitive electrical fault while P0972 is a performance issue. P0973 is more likely to cause immediate drivability problems like limp mode.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0973 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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