P1795 — CAN Bus Throttle Body Position

Causes

• Open, short, or high-resistance wiring in the CAN bus pair or throttle body connector
• Poor or corroded ground(s) or power supply to the throttle body or related modules
• Faulty electronic throttle body (ETB) / throttle actuator control (TAC) module or internal TPS
• Faulty PCM/TCM or other module on the CAN network sending incorrect data
• Missing or incorrect CAN bus termination (bad/missing 120 Ω resistors or broken wiring)
• Intermittent connector contact or bent pins at throttle body or control modules

Symptoms

• Check Engine Light (MIL) illuminated
• Reduced engine power or 'limp' mode
• Poor throttle response, hesitation, or surging
• Idle problems or unexpected stalling
• No or inconsistent throttle position values shown on scan tool
• Other modules reporting communication errors (U-codes)

What to check

• Read all stored DTCs (powertrain and network modules) and record freeze-frame data
• Use a scan tool to monitor throttle position (ETB) and accelerator pedal position (APP) live data and compare values
• Check for CAN bus related U-codes (U0100, U0073, etc.) indicating broader communication loss
• Visually inspect throttle body connector, harness and CAN bus wiring for damage, corrosion or poor routing
• Verify battery voltage and engine grounds are good under load and key-on conditions
• Measure CAN high and CAN low voltages at the throttle body connector (key ON, engine OFF) and at the PCM

Signal parameters

• Throttle position sensor: expected voltage range ~0.5–4.5 V (vehicle-specific), throttle angle 0–100%
• Accelerator pedal position: expected correlation with throttle position (both should increase together)
• CAN bus idle common-mode ~2.5 V on both CAN_H and CAN_L; dominant bits drive CAN_H ≈ 3.5 V and CAN_L ≈ 1.5 V (values vary slightly by vehicle)
• CAN bus termination: approximately 60 ohms measured between CAN_H and CAN_L with key OFF/ON (two 120 Ω terminators in parallel)
• Battery voltage: nominal 12.0–14.5 V during tests

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