What Does P2802 Mean?
The PCM has detected an abnormally low voltage signal from the Transmission Range Sensor 'B' circuit. The signal voltage is below the minimum threshold expected for any valid gear position.
Common Causes
30%
Open circuit in TR sensor B wiring or poor ground connection
25%
Shorted transmission range sensor B circuit to ground
25%
Failed transmission range sensor B with internal short or open
15%
Corroded or damaged TR sensor connector causing high resistance
5%
Loss of reference voltage supply to TR sensor due to PCM/TCM fault
Diagnostic Steps
1
Step 1: Measure voltage at TR sensor B connector with ignition on; should see reference voltage (typically 5V or 12V)
2
Step 2: Backprobe signal wire at sensor connector and check voltage in each gear position; compare to specifications
3
Step 3: Check continuity and resistance of TR sensor B signal and ground circuits from sensor to PCM/TCM
4
Step 4: Inspect wiring harness for damage, especially near transmission where heat and vibration occur
5
Step 5: If circuits test good, replace TR sensor B and verify proper voltage readings are restored
Estimated Repair Cost
$180 - $500
Parts + labor, varies by vehicle and location
The PCM has detected an abnormally low voltage signal from the Transmission Range Sensor 'B' circuit. The signal voltage is below the minimum threshold expected for any valid gear position.
The most common cause of P2802 (Transmission Range Sensor "B" Circuit Low) is: Open circuit in TR sensor B wiring or poor ground connection
Typical repair costs for P2802 range from $180 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may not recognize gear position, potentially allowing starter engagement while in gear. Transmission may default to limp mode with limited gear availability.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2802 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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