P1156 Volkswagen – Manifold Absolute Pressure Sensor Open/Short to Ground

🚨 Code P1156 Volkswagen: Problem with the Manifold Absolute Pressure Sensor

❓ Meaning of Code P1156

The code P1156 for Volkswagen vehicles indicates a problem with the manifold absolute pressure sensor. This sensor measures the air pressure in the intake manifold and is essential for adjusting the air-fuel mixture to optimize engine performance.

The code triggers when there is a short circuit or an electrical problem with the manifold absolute pressure sensor.

⚠️ Although the generic description of code P1156 is related to a short circuit or open connection, the exact details may vary depending on your vehicle’s model and year. Consult the manufacturer’s manual for more precise information.

⚠️ Possible Symptoms

When code P1156 is present, you may observe the following symptoms:

  • Engine light on (check engine)

  • Engine service warning light soon

These symptoms suggest a malfunction in the engine management system related to the manifold pressure.

🔧 Possible Causes

Possible causes of code P1156 include:

  1. Faulty manifold absolute pressure sensor: The sensor may be defective or miscalibrated.

  2. Open or shorted manifold absolute pressure sensor harness: The electrical harness connecting the sensor may be cut or short-circuited.

  3. Poor electrical connection in the sensor circuit: Poorly made or corroded electrical connections can prevent the sensor from functioning properly.

🛠️ How to Fix Code P1156

To resolve code P1156, follow these diagnostic and repair steps:

  1. Check possible causes:

    • Visually inspect the wiring harness and connectors of the manifold absolute pressure sensor.

    • Look for damaged components, broken, bent, pushed, or corroded pins.

  2. Test the manifold absolute pressure sensor:

    • If the harness and connectors are in good condition, test the sensor itself.

    • If the sensor is faulty, it will need to be replaced.

  3. Check electrical connections:

    • Inspect all electrical connections at the sensor. Ensure they are clean and securely fastened.

✅ Conclusion

Code P1156 indicates a problem with the manifold absolute pressure sensor or its electrical circuit on a Volkswagen vehicle. To correct the issue, it is essential to first check the wiring harness, connectors, and electrical connections, then test the sensor itself. Once the problem is identified and resolved, the code can be cleared using an OBD-II scanner.

P1157 – Air/Fuel Ratio Sensor 1 Range/Performance Problem

P1157 Possible Causes

  • Faulty Air/Fuel Ratio Sensor 1
  • Air/Fuel Ratio Sensor 1 harness is open or shorted
  • Poor electrical connection in Air/Fuel Ratio Sensor 1 circuit

How to Fix Code P1157?

Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Engine Light On (or Service Engine Soon Warning Light)

P1157 Meaning

The Air/Fuel Ratio (A/F) Sensor 1 is installed in the exhaust system and detects the oxygen concentration in the exhaust gases. The A/F sensor sends the output voltage to the Engine Control Module (ECM). A heating element for the sensor element is built into the A/F sensor (Sensor 1). It is activated and heats the sensor to stabilize and speed up the detection of oxygen concentration by controlling the current flowing through the heater. An increase in current stabilizes when the voltage applied to the element electrode reaches a certain range because the amount of oxygen that is channeled through the diffusion layer is limited. The current amperage is proportional to the oxygen concentration in the exhaust gases, so the air/fuel ratio is detected by measuring the current amperage. The ECM compares a set target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.
If the A/F sensor (Sensor 1) voltage is low, the air/fuel ratio is lean and the ECM uses A/F feedback control to issue a Rich command. If the A/F sensor (Sensor 1) voltage is high, the air/fuel ratio is rich and the ECM uses A/F feedback control to issue a Lean command.

P1157 1997 FORD F150 – Lack of Heated Oxygen Sensor Switches, Bank 2 Sensor 2 Indicates Lean

P1157 1997 FORD F150 Possible Causes

  • Exhaust gas leaks
  • Faulty Heated Oxygen Sensor 2 (HO2S2) (downstream), Bank 2
  • Heated Oxygen Sensor 2, Bank 2 harness is open or shorted
  • Heated Oxygen Sensor 2, Bank 2 circuit poor electrical connection
  • Inappropriate fuel pressure
  • Faulty fuel injectors

How to Fix Code P1157 1997 FORD F150?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Engine Light On (or Service Engine Soon Warning Light)

P1157 1997 FORD F150 Meaning

The Heated Oxygen Sensor 2 (HO2S2) (downstream), after the Three-Way Catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must remain close to the ideal stoichiometric ratio. The HO2S2 output voltage changes abruptly near the stoichiometric ratio. The Powertrain Control Module (PCM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S2 generates a voltage between 0.1 and 0.9 V in response to the oxygen in the exhaust gases. If the oxygen in the exhaust gases increases, the air-fuel ratio becomes lean. The PCM interprets Lean when the HO2S2 voltage is below 0.45 V. If the oxygen in the exhaust gases decreases, the air-fuel ratio becomes rich. The PCM interprets Rich when the HO2S2 voltage is above 0.45 V.

P1157 HONDA – Air/Fuel Ratio Sensor 1 Range/Performance Problem

P1157 2008 HONDA ACCORD Possible Causes

  • Faulty Air/Fuel Ratio Sensor 1
  • Air/Fuel Ratio Sensor 1 harness is open or shorted
  • Poor electrical connection in the Air/Fuel Ratio Sensor 1 circuit

How to Fix Code P1157 2008 HONDA ACCORD?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

When is the Code Detected?

A malfunction is detected and the code is stored if the heater element is not activated or if the voltage at the Engine Control Module (ECM) terminals is a specified value or less for at least a specified period of time when power is supplied to the A/F sensor heater (sensor 1).

Possible Symptoms

  • Check Engine Light On (or Service Engine Soon Warning Light)

P1157 2008 HONDA ACCORD Meaning

The Air/Fuel Ratio (A/F) Sensor 1 is installed in the exhaust system and detects the oxygen concentration in the exhaust gases. The A/F sensor sends the output voltage to the Engine Control Module (ECM). A heating element for the sensor element is built into the A/F sensor (sensor 1). It is activated and heats the sensor to stabilize and speed up the detection of the oxygen concentration by controlling the current flowing through the heater. An increase in current stabilizes when the voltage applied to the element electrode reaches a certain range because the amount of oxygen that is routed through the diffusion layer is limited. The current amperage is proportional to the oxygen concentration in the exhaust gases, so the air/fuel ratio is detected by measuring the current amperage. The ECM compares a preset target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.
If the A/F sensor (sensor 1) voltage is low, the air/fuel ratio is lean and the ECM uses A/F feedback control to issue a Rich command. If the A/F sensor (sensor 1) voltage is high, the air/fuel ratio is rich and the ECM uses A/F feedback control to issue a Lean command.

P1157 ACURA – Air/Fuel Ratio Sensor 1 Range/Performance Problem

P1157 ACURA Possible Causes

  • Faulty Air/Fuel Ratio Sensor 1
  • Air/Fuel Ratio Sensor 1 harness is open or shorted
  • Air/Fuel Ratio Sensor 1 circuit poor electrical connection

How to Fix Code P1157 ACURA?

Start by checking the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

When is the Code Detected?

A malfunction is detected and the code is stored if the heater element is not activated or if the voltage at the Engine Control Module (ECM) terminals is a specified value or less for at least a specified period of time when power is supplied to the A/F sensor heater (Sensor 1).

Possible Symptoms

  • Check Engine Light On (or Service Engine Soon Warning Light)

P1157 ACURA Meaning

The Air/Fuel Ratio (A/F) Sensor 1 is installed in the exhaust system and detects the oxygen concentration in the exhaust gases. The A/F sensor sends the output voltage to the Engine Control Module (ECM). A heating element for the sensor element is built into the A/F sensor (Sensor 1). It is activated and heats the sensor to stabilize and speed up the detection of oxygen concentration by controlling the current flowing through the heater. The current increase stabilizes when the voltage applied to the element electrode reaches a certain range because the amount of oxygen that is transported through the diffusion layer is limited. The current amperage is proportional to the oxygen concentration in the exhaust gases, so the air/fuel ratio is detected by measuring the current amperage. The ECM compares a preset target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.
If the A/F sensor (Sensor 1) voltage is low, the air/fuel ratio is lean and the ECM uses A/F feedback control to issue a Rich command. If the A/F sensor (Sensor 1) voltage is high, the air/fuel ratio is rich and the ECM uses A/F feedback control to issue a Lean command.

P1157 AUDI – Manifold Absolute Pressure Sensor Supply Voltage

P1157 AUDI Possible Causes

  • Faulty manifold absolute pressure sensor
  • Manifold absolute pressure sensor harness is open or shorted
  • Poor electrical connection in the manifold absolute pressure sensor circuit
 

How to fix P1157 AUDI code?

Start by checking the “possible causes” listed above. Visually inspect the corresponding cable harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

 
 

Possible Symptoms

  • Engine light on (or service engine soon warning light)
 

P1157 AUDI Meaning

Manifold Absolute Pressure Sensor Supply Voltage is the generic description for Audi P1157 code, but the manufacturer may have a different description for your model and vehicle year. Currently, we don’t have more information about the Audi P1157 OBDII code.

P1157 BMW – O2 Sensor Heater Circuit High Voltage, Bank 2 Sensor 2

P1157 BMW Possible Causes

  • Faulty O2 sensor heater, bank 2 sensor 2
  • Open or short circuit in O2 sensor heater bank 2 sensor 2 wiring harness
  • O2 sensor heater circuit, bank 2 sensor 2, poor electrical connection in the circuit

How to Fix BMW P1157 Code?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Check engine light on (or service engine soon warning light)

P1157 BMW Meaning

High voltage in O2 sensor heater circuit, bank 2 sensor 2 is the generic description for BMW P1157 code, but the manufacturer may have a different description for your vehicle model and year. Currently, we do not have more information about the P1157 BMW OBDII code.

P1157 BUICK – HO2S Bank 2 Sensor 2 Lean or Low Voltage System

P1157 BUICK Possible Causes

  • Faulty O2 sensor heater, Bank 2 Sensor 2
  • O2 sensor heater Bank 2 Sensor 2 harness is open or shorted
  • O2 sensor heater circuit, Bank 2, Sensor 2 circuit poor electrical connection
 

How to Fix Code P1157 BUICK?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

 
 

Possible Symptoms

  • Engine light on (or service engine soon warning light)
 

P1157 BUICK Meaning

HO2S Bank 2 Sensor 2 Lean System or Low Voltage is the generic description for Buick code P1157, but the manufacturer may have a different description for your vehicle model and year. Currently, we do not have more information about OBDII code P1157 Buick.

P1157 CADILLAC – HO2S Bank 2 Sensor 2 Lean or Low Voltage System

P1157 CADILLAC Possible Causes

  • Faulty O2 sensor heater, Bank 2 Sensor 2
  • Open or short circuit in Bank 2 Sensor 2 O2 sensor heater wiring
  • O2 sensor heater circuit, Bank 2 Sensor 2, poor electrical connection in the sensor circuit

How to Fix Code P1157 CADILLAC?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Engine light on (or engine service warning light soon)

P1157 CADILLAC Meaning

HO2S Bank 2 Sensor 2 System Lean or Low Voltage is the generic description for Cadillac code P1157, but the manufacturer may have a different description for your vehicle model and year. Currently, we have no further information on Cadillac OBDII code P1157.

P1157 CHEVROLET – HO2S Bank 2 Sensor 2 Lean or Low Voltage System

P1157 CHEVROLET Possible Causes

  • Faulty O2 sensor heater, bank 2 sensor 2
  • O2 sensor heater bank 2 sensor 2 harness is open or shorted
  • O2 sensor heater circuit, bank 2, sensor 2 circuit poor electrical connection
 

How to Fix Code P1157 CHEVROLET?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

 
 

Possible Symptoms

  • Engine light on (or service engine soon warning light)
 

P1157 CHEVROLET Meaning

HO2S Bank 2 sensor 2 System lean or low voltage is the generic description for Chevrolet code P1157, but the manufacturer may have a different description for your vehicle model and year. Currently, we have no further information about Chevrolet OBDII code P1157.