Home / DTC / P1419 — Catalytic converter downstream temperature sensor short circuit to positive or open circuit

P1419 — Catalytic converter downstream temperature sensor short circuit to positive or open circuit

Detailed page for trouble code P1419.

34,405codes
59brands
11,914generic
22,491specific
Reset
Code

P1419

CITROEN P — Powertrain

Catalytic converter downstream temperature sensor short circuit to positive or open circuit

Brand: CITROEN
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Broken or shorted wiring in the sensor/ECU harness (short to battery/positive or open circuit)
  • Corroded, loose or contaminated sensor connector pins
  • Failed downstream catalytic converter temperature sensor (NTC/thermistor or sensor heater)
  • Blown fuse or fault in an upstream relay supplying the sensor/heater circuit
  • ECU internal fault (rare) or incorrect ECU grounding

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated and P1419 stored
  • Possible failed emissions test or active catalyst-related limp conditions
  • Reduced feedback for catalyst control — erratic emissions control or fuel trims
  • Noisy or intermittent diagnostic data from downstream temperature channel
  • Possible limited driveability if ECU enters protective strategies (rare)

What to check

  • Read DTCs and freeze-frame data with a scan tool; note pending vs stored status
  • Visually inspect downstream sensor wiring, connector, and mounting for heat/chafe/corrosion
  • Backprobe the sensor connector with ignition ON to check reference voltage and ground presence
  • Measure sensor resistance (thermistor) at ambient temperature and compare to spec
  • Check for continuity between the sensor signal/heater wires and battery positive (short) and to open circuit
  • Measure heater circuit resistance (if applicable) and check for battery voltage supply when heater is commanded

Signal parameters

  • Sensor type: typically an NTC thermistor element — resistance falls as temperature rises
  • Expected behavior: sensor voltage varies with temperature (typical ECU input range ~0.1–5.0 V depending on temp and ECU reference — consult vehicle spec)
  • Ambient/room temperature resistance is usually in the kilo-ohm range (manufacturer-specific); consult Citroën service data for exact values
  • Heater circuit (if present): feed should show battery voltage when active and low ohm resistance across heater element (spec varies by sensor)
  • P1419 indicates either an open circuit (very high resistance/infinite) or a short to positive (voltage stuck near battery voltage) on sensor or heater circuit

Diagnostic algorithm

  1. Connect a diagnostic scan tool, confirm P1419 and any related codes; record freeze-frame and live downstream temperature values.
  2. Visually inspect sensor, connector and wiring from sensor to ECU for heat damage, chafing, pin corrosion, or rodent damage; repair obvious damage.
  3. With ignition ON (engine OFF), backprobe connector: check for proper reference/return voltages per wiring diagram; note if voltage is stuck at battery (short to positive) or absent (open).
  4. Disconnect sensor and measure thermistor resistance at ambient; compare to manufacturer spec. Infinite/open = thermistor failure; short/very low resistance may indicate heater short.
  5. Check for short to battery: measure continuity between signal/heater wires and battery positive; isolate sections of harness to find short location.
  6. Measure heater circuit resistance (if equipped) between heater pins and verify battery feed when heater commanded by ECU (use scan tool to actuate if available).
  7. Wiggle harness and connectors while monitoring live data to find intermittent faults; repair or replace damaged wiring or connectors.
  8. If wiring and connectors test OK and replacement sensor available, fit a known-good sensor and re-test.
  9. Clear codes, road test and re-scan. If code returns and wiring checks are OK, consider ECU fault and consult manufacturer guidance before replacement.

Likely causes

  • Damaged insulation allowing sensor signal or heater wire to contact battery feed
  • Connector corrosion or pin damage at the downstream sensor
  • Open thermistor element or broken heater winding inside the sensor
  • Faulty sensor replacement or installation fault
  • Intermittent harness damage near exhaust, mounting bracket, or flex areas

Fault status

⚠️ Status
P1419 stored — downstream catalytic converter temperature sensor circuit indicates open or short-to-positive. MIL may be illuminated. This fault affects emissions monitoring; the ECU may ignore downstream temperature input until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Your experience will help others
+100 karma for a short comment :)
Send to email
Code

P1419

DAEWOO P — Powertrain

2 ND AIR JINECTION V/V

Brand: DAEWOO
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Broken or shorted wiring in the sensor/ECU harness (short to battery/positive or open circuit)
  • Corroded, loose or contaminated sensor connector pins
  • Failed downstream catalytic converter temperature sensor (NTC/thermistor or sensor heater)
  • Blown fuse or fault in an upstream relay supplying the sensor/heater circuit
  • ECU internal fault (rare) or incorrect ECU grounding

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated and P1419 stored
  • Possible failed emissions test or active catalyst-related limp conditions
  • Reduced feedback for catalyst control — erratic emissions control or fuel trims
  • Noisy or intermittent diagnostic data from downstream temperature channel
  • Possible limited driveability if ECU enters protective strategies (rare)

What to check

  • Read DTCs and freeze-frame data with a scan tool; note pending vs stored status
  • Visually inspect downstream sensor wiring, connector, and mounting for heat/chafe/corrosion
  • Backprobe the sensor connector with ignition ON to check reference voltage and ground presence
  • Measure sensor resistance (thermistor) at ambient temperature and compare to spec
  • Check for continuity between the sensor signal/heater wires and battery positive (short) and to open circuit
  • Measure heater circuit resistance (if applicable) and check for battery voltage supply when heater is commanded

Signal parameters

  • Sensor type: typically an NTC thermistor element — resistance falls as temperature rises
  • Expected behavior: sensor voltage varies with temperature (typical ECU input range ~0.1–5.0 V depending on temp and ECU reference — consult vehicle spec)
  • Ambient/room temperature resistance is usually in the kilo-ohm range (manufacturer-specific); consult Citroën service data for exact values
  • Heater circuit (if present): feed should show battery voltage when active and low ohm resistance across heater element (spec varies by sensor)
  • P1419 indicates either an open circuit (very high resistance/infinite) or a short to positive (voltage stuck near battery voltage) on sensor or heater circuit

Diagnostic algorithm

  1. Connect a diagnostic scan tool, confirm P1419 and any related codes; record freeze-frame and live downstream temperature values.
  2. Visually inspect sensor, connector and wiring from sensor to ECU for heat damage, chafing, pin corrosion, or rodent damage; repair obvious damage.
  3. With ignition ON (engine OFF), backprobe connector: check for proper reference/return voltages per wiring diagram; note if voltage is stuck at battery (short to positive) or absent (open).
  4. Disconnect sensor and measure thermistor resistance at ambient; compare to manufacturer spec. Infinite/open = thermistor failure; short/very low resistance may indicate heater short.
  5. Check for short to battery: measure continuity between signal/heater wires and battery positive; isolate sections of harness to find short location.
  6. Measure heater circuit resistance (if equipped) between heater pins and verify battery feed when heater commanded by ECU (use scan tool to actuate if available).
  7. Wiggle harness and connectors while monitoring live data to find intermittent faults; repair or replace damaged wiring or connectors.
  8. If wiring and connectors test OK and replacement sensor available, fit a known-good sensor and re-test.
  9. Clear codes, road test and re-scan. If code returns and wiring checks are OK, consider ECU fault and consult manufacturer guidance before replacement.

Likely causes

  • Damaged insulation allowing sensor signal or heater wire to contact battery feed
  • Connector corrosion or pin damage at the downstream sensor
  • Open thermistor element or broken heater winding inside the sensor
  • Faulty sensor replacement or installation fault
  • Intermittent harness damage near exhaust, mounting bracket, or flex areas

Fault status

⚠️ Status
P1419 stored — downstream catalytic converter temperature sensor circuit indicates open or short-to-positive. MIL may be illuminated. This fault affects emissions monitoring; the ECU may ignore downstream temperature input until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Repair manuals

Manual library for DAEWOO

75

Browse 75 DAEWOO manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

DAEWOO

Your experience will help others
+100 karma for a short comment :)
Send to email
Code

P1419

DS P — Powertrain

Catalytic converter downstream temperature sensor short circuit to positive or open circuit

Brand: DS
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Broken or shorted wiring in the sensor/ECU harness (short to battery/positive or open circuit)
  • Corroded, loose or contaminated sensor connector pins
  • Failed downstream catalytic converter temperature sensor (NTC/thermistor or sensor heater)
  • Blown fuse or fault in an upstream relay supplying the sensor/heater circuit
  • ECU internal fault (rare) or incorrect ECU grounding

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated and P1419 stored
  • Possible failed emissions test or active catalyst-related limp conditions
  • Reduced feedback for catalyst control — erratic emissions control or fuel trims
  • Noisy or intermittent diagnostic data from downstream temperature channel
  • Possible limited driveability if ECU enters protective strategies (rare)

What to check

  • Read DTCs and freeze-frame data with a scan tool; note pending vs stored status
  • Visually inspect downstream sensor wiring, connector, and mounting for heat/chafe/corrosion
  • Backprobe the sensor connector with ignition ON to check reference voltage and ground presence
  • Measure sensor resistance (thermistor) at ambient temperature and compare to spec
  • Check for continuity between the sensor signal/heater wires and battery positive (short) and to open circuit
  • Measure heater circuit resistance (if applicable) and check for battery voltage supply when heater is commanded

Signal parameters

  • Sensor type: typically an NTC thermistor element — resistance falls as temperature rises
  • Expected behavior: sensor voltage varies with temperature (typical ECU input range ~0.1–5.0 V depending on temp and ECU reference — consult vehicle spec)
  • Ambient/room temperature resistance is usually in the kilo-ohm range (manufacturer-specific); consult Citroën service data for exact values
  • Heater circuit (if present): feed should show battery voltage when active and low ohm resistance across heater element (spec varies by sensor)
  • P1419 indicates either an open circuit (very high resistance/infinite) or a short to positive (voltage stuck near battery voltage) on sensor or heater circuit

Diagnostic algorithm

  1. Connect a diagnostic scan tool, confirm P1419 and any related codes; record freeze-frame and live downstream temperature values.
  2. Visually inspect sensor, connector and wiring from sensor to ECU for heat damage, chafing, pin corrosion, or rodent damage; repair obvious damage.
  3. With ignition ON (engine OFF), backprobe connector: check for proper reference/return voltages per wiring diagram; note if voltage is stuck at battery (short to positive) or absent (open).
  4. Disconnect sensor and measure thermistor resistance at ambient; compare to manufacturer spec. Infinite/open = thermistor failure; short/very low resistance may indicate heater short.
  5. Check for short to battery: measure continuity between signal/heater wires and battery positive; isolate sections of harness to find short location.
  6. Measure heater circuit resistance (if equipped) between heater pins and verify battery feed when heater commanded by ECU (use scan tool to actuate if available).
  7. Wiggle harness and connectors while monitoring live data to find intermittent faults; repair or replace damaged wiring or connectors.
  8. If wiring and connectors test OK and replacement sensor available, fit a known-good sensor and re-test.
  9. Clear codes, road test and re-scan. If code returns and wiring checks are OK, consider ECU fault and consult manufacturer guidance before replacement.

Likely causes

  • Damaged insulation allowing sensor signal or heater wire to contact battery feed
  • Connector corrosion or pin damage at the downstream sensor
  • Open thermistor element or broken heater winding inside the sensor
  • Faulty sensor replacement or installation fault
  • Intermittent harness damage near exhaust, mounting bracket, or flex areas

Fault status

⚠️ Status
P1419 stored — downstream catalytic converter temperature sensor circuit indicates open or short-to-positive. MIL may be illuminated. This fault affects emissions monitoring; the ECU may ignore downstream temperature input until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Your experience will help others
+100 karma for a short comment :)
Send to email
Code

P1419

MAZDA P — Powertrain

Split Air 2 Circuit

Brand: MAZDA
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Broken or shorted wiring in the sensor/ECU harness (short to battery/positive or open circuit)
  • Corroded, loose or contaminated sensor connector pins
  • Failed downstream catalytic converter temperature sensor (NTC/thermistor or sensor heater)
  • Blown fuse or fault in an upstream relay supplying the sensor/heater circuit
  • ECU internal fault (rare) or incorrect ECU grounding

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated and P1419 stored
  • Possible failed emissions test or active catalyst-related limp conditions
  • Reduced feedback for catalyst control — erratic emissions control or fuel trims
  • Noisy or intermittent diagnostic data from downstream temperature channel
  • Possible limited driveability if ECU enters protective strategies (rare)

What to check

  • Read DTCs and freeze-frame data with a scan tool; note pending vs stored status
  • Visually inspect downstream sensor wiring, connector, and mounting for heat/chafe/corrosion
  • Backprobe the sensor connector with ignition ON to check reference voltage and ground presence
  • Measure sensor resistance (thermistor) at ambient temperature and compare to spec
  • Check for continuity between the sensor signal/heater wires and battery positive (short) and to open circuit
  • Measure heater circuit resistance (if applicable) and check for battery voltage supply when heater is commanded

Signal parameters

  • Sensor type: typically an NTC thermistor element — resistance falls as temperature rises
  • Expected behavior: sensor voltage varies with temperature (typical ECU input range ~0.1–5.0 V depending on temp and ECU reference — consult vehicle spec)
  • Ambient/room temperature resistance is usually in the kilo-ohm range (manufacturer-specific); consult Citroën service data for exact values
  • Heater circuit (if present): feed should show battery voltage when active and low ohm resistance across heater element (spec varies by sensor)
  • P1419 indicates either an open circuit (very high resistance/infinite) or a short to positive (voltage stuck near battery voltage) on sensor or heater circuit

Diagnostic algorithm

  1. Connect a diagnostic scan tool, confirm P1419 and any related codes; record freeze-frame and live downstream temperature values.
  2. Visually inspect sensor, connector and wiring from sensor to ECU for heat damage, chafing, pin corrosion, or rodent damage; repair obvious damage.
  3. With ignition ON (engine OFF), backprobe connector: check for proper reference/return voltages per wiring diagram; note if voltage is stuck at battery (short to positive) or absent (open).
  4. Disconnect sensor and measure thermistor resistance at ambient; compare to manufacturer spec. Infinite/open = thermistor failure; short/very low resistance may indicate heater short.
  5. Check for short to battery: measure continuity between signal/heater wires and battery positive; isolate sections of harness to find short location.
  6. Measure heater circuit resistance (if equipped) between heater pins and verify battery feed when heater commanded by ECU (use scan tool to actuate if available).
  7. Wiggle harness and connectors while monitoring live data to find intermittent faults; repair or replace damaged wiring or connectors.
  8. If wiring and connectors test OK and replacement sensor available, fit a known-good sensor and re-test.
  9. Clear codes, road test and re-scan. If code returns and wiring checks are OK, consider ECU fault and consult manufacturer guidance before replacement.

Likely causes

  • Damaged insulation allowing sensor signal or heater wire to contact battery feed
  • Connector corrosion or pin damage at the downstream sensor
  • Open thermistor element or broken heater winding inside the sensor
  • Faulty sensor replacement or installation fault
  • Intermittent harness damage near exhaust, mounting bracket, or flex areas

Fault status

⚠️ Status
P1419 stored — downstream catalytic converter temperature sensor circuit indicates open or short-to-positive. MIL may be illuminated. This fault affects emissions monitoring; the ECU may ignore downstream temperature input until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Your experience will help others
+100 karma for a short comment :)
Send to email
Code

P1419

Other P — Powertrain

Split Air #2 Circuit Malfunction

Brand: Other
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Broken or shorted wiring in the sensor/ECU harness (short to battery/positive or open circuit)
  • Corroded, loose or contaminated sensor connector pins
  • Failed downstream catalytic converter temperature sensor (NTC/thermistor or sensor heater)
  • Blown fuse or fault in an upstream relay supplying the sensor/heater circuit
  • ECU internal fault (rare) or incorrect ECU grounding

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated and P1419 stored
  • Possible failed emissions test or active catalyst-related limp conditions
  • Reduced feedback for catalyst control — erratic emissions control or fuel trims
  • Noisy or intermittent diagnostic data from downstream temperature channel
  • Possible limited driveability if ECU enters protective strategies (rare)

What to check

  • Read DTCs and freeze-frame data with a scan tool; note pending vs stored status
  • Visually inspect downstream sensor wiring, connector, and mounting for heat/chafe/corrosion
  • Backprobe the sensor connector with ignition ON to check reference voltage and ground presence
  • Measure sensor resistance (thermistor) at ambient temperature and compare to spec
  • Check for continuity between the sensor signal/heater wires and battery positive (short) and to open circuit
  • Measure heater circuit resistance (if applicable) and check for battery voltage supply when heater is commanded

Signal parameters

  • Sensor type: typically an NTC thermistor element — resistance falls as temperature rises
  • Expected behavior: sensor voltage varies with temperature (typical ECU input range ~0.1–5.0 V depending on temp and ECU reference — consult vehicle spec)
  • Ambient/room temperature resistance is usually in the kilo-ohm range (manufacturer-specific); consult Citroën service data for exact values
  • Heater circuit (if present): feed should show battery voltage when active and low ohm resistance across heater element (spec varies by sensor)
  • P1419 indicates either an open circuit (very high resistance/infinite) or a short to positive (voltage stuck near battery voltage) on sensor or heater circuit

Diagnostic algorithm

  1. Connect a diagnostic scan tool, confirm P1419 and any related codes; record freeze-frame and live downstream temperature values.
  2. Visually inspect sensor, connector and wiring from sensor to ECU for heat damage, chafing, pin corrosion, or rodent damage; repair obvious damage.
  3. With ignition ON (engine OFF), backprobe connector: check for proper reference/return voltages per wiring diagram; note if voltage is stuck at battery (short to positive) or absent (open).
  4. Disconnect sensor and measure thermistor resistance at ambient; compare to manufacturer spec. Infinite/open = thermistor failure; short/very low resistance may indicate heater short.
  5. Check for short to battery: measure continuity between signal/heater wires and battery positive; isolate sections of harness to find short location.
  6. Measure heater circuit resistance (if equipped) between heater pins and verify battery feed when heater commanded by ECU (use scan tool to actuate if available).
  7. Wiggle harness and connectors while monitoring live data to find intermittent faults; repair or replace damaged wiring or connectors.
  8. If wiring and connectors test OK and replacement sensor available, fit a known-good sensor and re-test.
  9. Clear codes, road test and re-scan. If code returns and wiring checks are OK, consider ECU fault and consult manufacturer guidance before replacement.

Likely causes

  • Damaged insulation allowing sensor signal or heater wire to contact battery feed
  • Connector corrosion or pin damage at the downstream sensor
  • Open thermistor element or broken heater winding inside the sensor
  • Faulty sensor replacement or installation fault
  • Intermittent harness damage near exhaust, mounting bracket, or flex areas

Fault status

⚠️ Status
P1419 stored — downstream catalytic converter temperature sensor circuit indicates open or short-to-positive. MIL may be illuminated. This fault affects emissions monitoring; the ECU may ignore downstream temperature input until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

8,907

The library contains 8,907 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

Your experience will help others
+100 karma for a short comment :)
Send to email
Code

P1419

PEUGEOT P — Powertrain

Catalytic converter downstream temperature sensor short circuit to positive or open circuit

Brand: PEUGEOT
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Broken or shorted wiring in the sensor/ECU harness (short to battery/positive or open circuit)
  • Corroded, loose or contaminated sensor connector pins
  • Failed downstream catalytic converter temperature sensor (NTC/thermistor or sensor heater)
  • Blown fuse or fault in an upstream relay supplying the sensor/heater circuit
  • ECU internal fault (rare) or incorrect ECU grounding

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated and P1419 stored
  • Possible failed emissions test or active catalyst-related limp conditions
  • Reduced feedback for catalyst control — erratic emissions control or fuel trims
  • Noisy or intermittent diagnostic data from downstream temperature channel
  • Possible limited driveability if ECU enters protective strategies (rare)

What to check

  • Read DTCs and freeze-frame data with a scan tool; note pending vs stored status
  • Visually inspect downstream sensor wiring, connector, and mounting for heat/chafe/corrosion
  • Backprobe the sensor connector with ignition ON to check reference voltage and ground presence
  • Measure sensor resistance (thermistor) at ambient temperature and compare to spec
  • Check for continuity between the sensor signal/heater wires and battery positive (short) and to open circuit
  • Measure heater circuit resistance (if applicable) and check for battery voltage supply when heater is commanded

Signal parameters

  • Sensor type: typically an NTC thermistor element — resistance falls as temperature rises
  • Expected behavior: sensor voltage varies with temperature (typical ECU input range ~0.1–5.0 V depending on temp and ECU reference — consult vehicle spec)
  • Ambient/room temperature resistance is usually in the kilo-ohm range (manufacturer-specific); consult Citroën service data for exact values
  • Heater circuit (if present): feed should show battery voltage when active and low ohm resistance across heater element (spec varies by sensor)
  • P1419 indicates either an open circuit (very high resistance/infinite) or a short to positive (voltage stuck near battery voltage) on sensor or heater circuit

Diagnostic algorithm

  1. Connect a diagnostic scan tool, confirm P1419 and any related codes; record freeze-frame and live downstream temperature values.
  2. Visually inspect sensor, connector and wiring from sensor to ECU for heat damage, chafing, pin corrosion, or rodent damage; repair obvious damage.
  3. With ignition ON (engine OFF), backprobe connector: check for proper reference/return voltages per wiring diagram; note if voltage is stuck at battery (short to positive) or absent (open).
  4. Disconnect sensor and measure thermistor resistance at ambient; compare to manufacturer spec. Infinite/open = thermistor failure; short/very low resistance may indicate heater short.
  5. Check for short to battery: measure continuity between signal/heater wires and battery positive; isolate sections of harness to find short location.
  6. Measure heater circuit resistance (if equipped) between heater pins and verify battery feed when heater commanded by ECU (use scan tool to actuate if available).
  7. Wiggle harness and connectors while monitoring live data to find intermittent faults; repair or replace damaged wiring or connectors.
  8. If wiring and connectors test OK and replacement sensor available, fit a known-good sensor and re-test.
  9. Clear codes, road test and re-scan. If code returns and wiring checks are OK, consider ECU fault and consult manufacturer guidance before replacement.

Likely causes

  • Damaged insulation allowing sensor signal or heater wire to contact battery feed
  • Connector corrosion or pin damage at the downstream sensor
  • Open thermistor element or broken heater winding inside the sensor
  • Faulty sensor replacement or installation fault
  • Intermittent harness damage near exhaust, mounting bracket, or flex areas

Fault status

⚠️ Status
P1419 stored — downstream catalytic converter temperature sensor circuit indicates open or short-to-positive. MIL may be illuminated. This fault affects emissions monitoring; the ECU may ignore downstream temperature input until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Your experience will help others
+100 karma for a short comment :)
Send to email