P1115

Code

VOLKSWAGEN P — Powertrain

Oxygen Sensor Heater Circuit Short To Ground Bank 1 Sensor 1

Brand: VOLKSWAGEN

Type: P — Powertrain

Views: UK: 45 EN: 120 RU: 71

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Page language: EN

Causes

Damaged or chafed wiring harness (short to ground) for Bank 1 Sensor 1 heater
Corroded, loose or damaged sensor connector pins
Failed oxygen sensor heater element internally shorted
Blown or shorted heater fuse or related relay (if equipped)
Aftermarket or poor-quality sensor with incorrect internal wiring
PCM or driver transistor failure (rare)

Symptoms

Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
Longer engine warm-up time and poor closed-loop operation until warmed
Increased fuel consumption and emissions
Failed emissions test
Possible rough idle during cold start

What to check

Read and record freeze frame and live data with OBD-II scanner; note heater control status and O2 voltages
Visually inspect harness and connector at Bank 1 Sensor 1 for damage, corrosion, heat damage or oil contamination
Check relevant fuses and relays for the oxygen sensor heater circuit
With key ON (engine off) backprobe connector to check for battery feed voltage on heater supply terminal
Measure resistance of the heater element at the sensor (with sensor unplugged) and compare to specification
Check continuity from heater return conductor to chassis ground (looking for unintended short)

Signal parameters

Heater supply voltage (key ON): ~11–14 V (varies by vehicle) on the heater feed circuit
Heater element resistance (sensor disconnected): typically ~2–14 ohms (manufacturer-specific) — a very low or near-zero reading suggests a short; an open/infinite reading suggests open circuit
Heater current when powered: typically ~0.5–3 A depending on sensor design
PCM control: many systems switch ground side or drive current PWM; scanner may show heater ON/OFF or duty cycle

Diagnostic algorithm

Connect a scan tool, read stored codes and freeze frame data. Confirm P1115 and note any related codes.
Visually inspect Bank 1 Sensor 1 harness and connector for chafing, heat damage, oil or corrosion. Repair visible damage.
With ignition OFF disconnect the sensor. Measure heater element resistance across heater terminals at the sensor. Compare to spec; very low (near 0 Ω) may indicate internal short, very high/open indicates open heater.
With sensor disconnected and ignition ON (engine off), backprobe the harness feed terminal and verify battery voltage on the heater supply circuit. If no supply, trace fuse/relay/power feed.
Measure continuity between the heater return conductor and chassis ground with the harness connected. A direct short (very low resistance) indicates wiring short to ground — locate and repair (inspect routing, look for pinched sections).
If wiring shows no short and heater resistance is incorrect, replace the oxygen sensor (Bank 1 Sensor 1) with OEM or equivalent quality part.
After repairs, clear codes, run engine to normal operating temperature and verify heater operation with live data/scan tool. Confirm code does not return during test drive.
If all wiring and sensor check good but fault persists, test PCM heater driver output per manufacturer procedures — consider PCM fault only after excluding wiring and sensor issues.

Likely causes

Wiring insulation abrasion contacting chassis or engine ground
Contaminated/corroded connector causing low resistance to ground
Defective heated oxygen sensor (internal short)

Fault status

⚠️ Status

Oxygen Sensor Heater Circuit Short To Ground — Bank 1 Sensor 1 (P1115)

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours

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P1115 — Oxygen Sensor Heater Circuit Short To Ground Bank 1 Sensor 1