Code
P1161
CHRYSLER
P — Powertrain
HO2S Heater Power Stage Circuit Bank 2 Sensor 2
Views:
UK: 46
EN: 47
RU: 55
AI status
Completed
Completed
100%
Causes
- Broken, chafed or shorted heater wiring/harness to Bank 2 Sensor 2
- Corroded, loose or contaminated sensor connector
- Failed HO2S (heater element open or shorted)
- Blown fuse or faulty relay supplying heater power
- PCM/power stage or ground circuit fault inside the engine control module
- Aftermarket electronics or recent repairs damaged the circuit
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Possible failed emissions test (exhaust monitoring incomplete)
- Long closed-loop warm-up or extended open-loop fueling (may affect fuel trim)
- No major driveability issues in many cases (downstream sensor heater less critical for immediate drivability)
What to check
- Scan for additional DTCs and capture freeze frame / live data for HO2S heater status and related PIDs
- Visual inspection of Bank 2 Sensor 2 connector and wiring for damage, corrosion, rodent chew, or pin push-out
- Check relevant fuses and power supply circuits for continuity and proper voltage
- Measure heater element resistance at the sensor (with sensor disconnected) and compare to spec
- Backprobe harness at sensor to verify supply voltage and PCM control (switching ground) while key ON / engine running as required
- Perform wiggle test on harness while monitoring for intermittent changes in heater circuit status
Signal parameters
- Heater resistance (sensor disconnected): typical range ~3–20 ohms (consult OEM spec for exact value)
- Heater supply voltage (key ON): battery voltage ~11–14 V (if circuit uses fused battery feed)
- PCM control: driver usually switches ground to enable heater; voltage at control pin will be pulsed/ground switching when active
- Heater current when on: typically under a few amps (varies by sensor); large currents or short-to-ground indicate fault
- If resistance is OL/infinite — open heater element; if very low near 0 ohms — shorted element
Diagnostic algorithm
- Confirm P1161 and any other related codes. Record freeze frame and live data for Bank 2 Sensor 2 heater status.
- Perform a careful visual inspection of the sensor connector, wiring harness route, and PCM connector for damage or corrosion.
- With ignition OFF, disconnect the sensor and measure heater element resistance between heater power and heater ground pins at the sensor. Compare to OEM spec.
- Check fuse(s) and any relay that supplies the heater circuit for presence and continuity. Replace if blown or faulty.
- With ignition ON (engine OFF), backprobe the sensor harness: verify battery feed voltage at heater supply pin and verify control/driver pin behavior (should be open or pulsed to ground when commanded).
- If supply voltage is present but heater element shows open/OL, replace the oxygen sensor and clear codes. Re-test.
- If supply voltage is absent, trace supply circuit back to fuse/relay/power source and repair wiring or replace fuse/relay.
- If supply is present and sensor heater resistance is good but PCM driver does not switch or shows short/overcurrent, test continuity between sensor and PCM, inspect PCM grounds. If wiring is good and driver still fails, consider PCM power stage fault and consult OEM procedures for PCM testing/repair.
- After repairs, clear codes and perform road test/drive cycle to confirm code does not return and heater operates as expected.
Likely causes
- Wiring/connectors (open, short to ground or short to battery) — most common
- Failed oxygen sensor heater element
- Blown fuse or poor battery feed to heater circuit
- PCM internal driver/power stage failure (less common)
Fault status
Status
PCM has detected a malfunction in the HO2S heater power stage for Bank 2 Sensor 2 — possible open/short in heater circuit, sensor heater failure, or driver/power stage fault.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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