Error Code P1153 is defined as Heated Oxygen Sensor (HO2S) Insufficient Switching Bank 2 Sensor 1. This means the HO2S didn’t switch enough times.

This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II system, particularly those made from 1996 up to present. Specifications on the definition, troubleshooting, and repairs of course, vary from one make and/or model to another.

Definition

The Air/Fuel ratio or more commonly known as HO2S or Heated Oxygen Sensor must reach a certain temperature (minimum of 1200˚ F to make an accurate voltage signal. The sooner the sensor gets to its minimum operating temperature, the faster the sensor will start to send accurate signals to the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes).

To reach this minimum operating temperature, a heater element is included as built-in component in the air/fuel ratio sensor, and is controlled by the PCM, based on the signals coming from the engine coolant temperature and engine load. Voltage signals received through the heater element circuit are also monitored by the PCM, which also determines the state of the circuit by comparing its voltage to the factory specifications of the vehicle.

When there is a problem on the signal, the Error Code P1153 is set, activating the Check Engine light on the dashboard.

Common Symptoms

As said earlier, this code activates the Check Engine light on the dashboard, which is its primary symptom.

Possible Causes

Different makes and models may have different causes for this error code. But majority of the time the most common causes are:

  • Faulty HO2S Bank 2 Sensor 1
  • HO2SShorted or open Bank 2 Sensor 1 harness
  • Poor electrical connection in HO2S Bank 2 Sensor 1 circuit
  • Faulty PCM (rare)

How to Check

First off, technicians start their diagnosis by checking the wiring for the harness and making sure there are no damaged wires. Next, they check the connections to make sure there are no loose or pulled connections.

From here they can replace the sensor, as damaged or faulty sensor is one of the most common causes for this problem.

They will also check the air/fuel sensors.

How to Fix

  • Repair or replace corroded or damaged wires
  • Repair or replace shorted or open electrical connections
  • Repair or replace loose connections
  • Replace Air/Fuel sensor or HO2S
  • Replace or reprogram PCM

In some cases, faulty PCM could be causing this error code, though this is quite rare. But if you have addressed other causes and the Check Engine light is still on, then there’s a possibility that the problem lies from the PCM. If such is the case, you need to take your vehicle to a certified technician to have your PCM removed, replaced, and updated. A Damaged or defective PCM can cause increase in fuel consumption, stalling or jerking with manual transmission, or shifting problems for automatic transmission.