What Does P0989 Mean?
DTC P0989 indicates the transmission fluid pressure sensor/switch "E" is reporting a voltage below the minimum threshold expected by the TCM. This low-signal condition typically points to a sensor circuit problem such as a short to ground, a failed sensor element, or an issue with the sensor's ground reference. The TCM may default to a fixed-pressure shift strategy.
Common Causes
30%
Short to ground in the pressure sensor "E" signal wire
30%
Internally failed pressure sensor with shorted or grounded output
20%
Corroded sensor connector allowing signal leakage to ground through moisture
15%
Damaged wiring insulation where the sensor harness contacts the transmission case
5%
TCM input circuit fault pulling the sensor signal low
Diagnostic Steps
1
Read live data for pressure sensor "E" to confirm the voltage is at or near zero, consistent with a low-circuit condition.
2
Disconnect the pressure sensor and measure the signal wire for continuity to ground; any continuity indicates a short in the harness.
3
Inspect the sensor connector for moisture, corrosion, or ATF contamination that could bridge the signal pin to ground.
4
With the sensor disconnected, check if the scan tool reading changes to a high or reference voltage; this confirms the sensor was pulling the signal low.
5
Replace the sensor if tests point to an internal failure; clear codes and verify that live data readings now track properly with transmission operation.
Estimated Repair Cost
$120 - $550
Parts + labor, varies by vehicle and location
DTC P0989 indicates the transmission fluid pressure sensor/switch "E" is reporting a voltage below the minimum threshold expected by the TCM. This low-signal condition typically points to a sensor circuit problem such as a short to ground, a failed sensor element, or an issue with the sensor's groun...
The most common cause of P0989 (Transmission Fluid Pressure Sensor/Switch "E" Circuit Low) is: Short to ground in the pressure sensor "E" signal wire
Typical repair costs for P0989 range from $120 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A perpetually low pressure reading causes the TCM to compensate by increasing line pressure, which can result in harsh, jarring shifts. While this protects the clutch packs, it reduces ride comfort and can stress transmission hard parts.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0989 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission
Difficulty
Type
Generic (SAE)
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