P1107

Code

VOLKSWAGEN P — Powertrain

Oxygen Sensor Heating Circuit Bank 2 Sensor 1 Short To B+

Brand: VOLKSWAGEN

Type: P — Powertrain

Views: UK: 38 EN: 59 RU: 44

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Page language: EN

Causes

Internal failure of Bank 2 Sensor 1 heater element (internal short)
Wiring short between the heater control/ground circuit and battery positive (B+)
Corroded, damaged or melted sensor connector or wiring harness
Blown or shorted fuse supplying heater power
Faulty ECU/PCM heater driver (less common)
Aftermarket electrical work or jump-starter damage to harness

Symptoms

Malfunction Indicator Lamp (MIL) on
Possible poor cold-start emissions and longer catalyst light-off time
Increased fuel consumption or rough idle until sensor(s) warm up
Failed emissions test
Possible other sensor heater circuits inoperative if fuse blown

What to check

Read and record freeze frame and live data using a scan tool; confirm P1107 is present and note conditions when it set
Visually inspect Bank 2 Sensor 1 connector, wiring and harness for burns, melting, corrosion, pin damage, or signs of heat
Check fuse(s) for the oxygen sensor heaters and related power distribution for continuity and correct rating
Backprobe the sensor connector with key ON (engine off): measure voltage on the heater power wire (should be fused B+, ~12V) and the control pin signal at the sensor connector
With sensor disconnected, measure resistance across the sensor heater pins at the sensor — compare to spec (typical low-ohm value)
Check for continuity between the heater control wire and battery positive (short) and between heater wires and chassis ground (open/short)

Signal parameters

Heater supply (power) wire: ~12V B+ (fused) with key ON
Heater control pin: ECU switches to ground; should not be held at B+
Typical upstream O2 heater resistance: generally low — commonly ~2–30 Ω (manufacturer-specific) — consult VW spec
Heater current draw: typically hundreds of milliamps to a few amps depending on sensor type
If short to B+ exists, control pin or ECU input may show battery voltage or abnormally high current draw

Diagnostic algorithm

Verify the code and capture freeze-frame/live data with a scan tool to confirm bank and sensor position
Turn ignition OFF and perform a visual inspection of sensor, connector and harness near the sensor and exhaust (look for heat damage/melted insulation)
Check relevant fuse(s) for the heater circuit; replace only after confirming cause of fuse failure
With ignition ON (engine off) backprobe the sensor connector: confirm heater power wire has battery voltage and measure the control pin; note unexpected B+ on control pin (indicates short to B+)
Disconnect the sensor and measure resistance across the heater element at the sensor plug; compare to spec. Very low or infinite resistance indicates internal short/open
With the sensor disconnected, check for continuity between the control wire and B+ (short) and between each heater wire and ground (unexpected continuity)
If wiring checks show harness short near sensor, repair/replace wiring and connector; if harness is OK but sensor heater resistance is out of spec, replace the oxygen sensor
If wiring and sensor test OK, backprobe ECU heater-control pin at the ECU connector to confirm driver behavior; if the ECU is applying B+ or showing internal short, consult factory procedures — ECU replacement is rare and should be last resort
After repairs clear codes and perform a drive cycle while monitoring heater circuit and O2 sensor operation to confirm code does not return

Likely causes

Damaged or contaminated sensor connector allowing B+ to contact the heater control pin
Frayed wiring or insulation chafing where heater control wire contacts a constant B+ supply
Failed heater element inside the oxygen sensor causing abnormal internal resistance and short to B+
Fuse or power-supply circuit fault supplying constant B+ when not intended

Fault status

⚠️ Status

P1107 — Oxygen sensor (Bank 2 Sensor 1) heater circuit: short to battery positive (B+).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

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P1107 — Oxygen Sensor Heating Circuit Bank 2 Sensor 1 Short To B+