What Does P0974 Mean?
The TCM has detected that the Shift Solenoid A (SS-A) control circuit voltage is consistently higher than expected, indicating a short to battery voltage or an open in the solenoid's ground return path. This keeps the solenoid in a fixed state opposite to the low-circuit condition, preventing proper gear selection. The transmission may be stuck in an unintended gear or may enter limp mode to protect internal components.
Safety Warning
An uncontrollable shift solenoid prevents normal gear changes. The vehicle may be stuck in one gear or enter limp mode. This limits speed and acceleration, creating potential hazards in highway merging situations. Drive minimally and have the vehicle repaired promptly.
Common Causes
35%
Open ground return path in the SS-A circuit
25%
Short to battery voltage in the SS-A wiring harness
20%
Corroded or backed-out ground pin at the transmission case connector
15%
Shift Solenoid A with open winding on the ground side
5%
TCM SS-A driver circuit stuck high
Diagnostic Steps
1
Measure SS-A resistance at the transmission connector — an extremely high or open reading suggests an open solenoid ground leg.
2
With the transmission connector disconnected, measure voltage on the SS-A wire at the TCM connector with key on. Persistent battery voltage with no load suggests a shorted-high harness or stuck TCM driver.
3
Verify continuity of the SS-A ground return from the solenoid through the internal harness, case connector, and external harness to the TCM ground reference.
4
Inspect the case connector for backed-out, corroded, or damaged ground pins. Verify all ground splices in the external harness are intact.
5
If wiring and solenoid test within specification, command SS-A on/off with the scan tool while monitoring circuit voltage at the TCM to confirm proper driver function.
Estimated Repair Cost
$200 - $1,400
Parts + labor, varies by vehicle and location
The TCM has detected that the Shift Solenoid A (SS-A) control circuit voltage is consistently higher than expected, indicating a short to battery voltage or an open in the solenoid's ground return path. This keeps the solenoid in a fixed state opposite to the low-circuit condition, preventing proper...
The most common cause of P0974 (Shift Solenoid "A" Control Circuit High) is: Open ground return path in the SS-A circuit
Typical repair costs for P0974 range from $200 to $1,400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
An uncontrollable shift solenoid prevents normal gear changes. The vehicle may be stuck in one gear or enter limp mode. This limits speed and acceleration, creating potential hazards in highway merging situations. Drive minimally and have the vehicle repaired promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0974 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission / Transaxle
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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