Troubleshooting the cause of a P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1) is not hard.
In this tutorial, I'm gonna' show you some of the basics you need to know about what DTC P0132 means and a step-by-step test of the upstream oxygen sensor.
Although this tutorial is geared toward a 3.9L, 5.2L, or 5.9L Dodge/Jeep pick up, van, or SUV; the info and test can be used on any 1996-2003 make or model.
Contents of this tutorial:
P0132 Basics You Need To Know
To get started, let's take a look at a few basic things about trouble code P0132. One of the most important things we need to know is that this code is referring to the performance of the upstream oxygen sensor. Here are the specifics:
LOCATION: This oxygen sensor is located before the catalytic converter and is known by several different names. The most common are:
- Upstream oxygen sensor.
- Pre-catalytic converter oxygen sensor.
- Front O2 sensor.
Your specific Dodge/Jeep vehicle may have one or two upstream oxygen sensors. To help you in finding the correct oxygen sensor, here are some more specifics:
- Vehicles with 2 upstream oxygen sensors, a P0132 DTC is identifying the one that's on Bank 1. Bank 1 is the bank of cylinders that have cylinders 1, 3, 5, and 7 (5.2L and 5.9L V-8 engines) and 1, 3, and 5 (3.9L V-6 engines).
- Vehicles with only 1 upstream oxygen sensor, a P0132 DTC is identifying the only one that's before the catalytic converter.
DEFINITION: P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1) diagnostic trouble code (DTC) is telling you that:
- The upstream oxygen sensor, located before the catalytic converter, is producing and thus reporting an excessively high voltage to the PCM (Powertrain Control Module). This continuous voltage will be a value over 0.5 Volts (500 millivolts).
- This high voltage value is being seen by the PCM for more than 2 minutes.
- This continuous high voltage is usually around 0.9 Volts DC (900 millivolts), although it can be a voltage value between 0.5 to 1 Volt (500 to 1000 millivolts).
- Any continuous voltage above 0.5 Volts indicates a Rich condition but not always, since the O2 sensor can fail and produce the same result (although a Rich condition does not really exists)
- In a nutshell, a Rich condition simply refers to the fact that an excessive amount of fuel is being injected into the engine.
OPERATION: In a normally operating engine, the front (upstream) O2 sensors will produce a voltage that will constantly and rapidly change between 0.1 Volt to 0.9 Volts DC.
So, when a P0132 is lighting up the check engine light (CEL), the PCM is seeing a voltage that stays continually fixed somewhere above 0.5 Volts for more than 2 minutes.
PROBABLE CAUSES: Several things can cause a P0132 diagnostic trouble code, the most common causes of a P0132 DTC are:
- Bad oxygen sensor.
- This is probably the most common cause of a P0132 DTC (but not always).
- The oxygen sensor fails internally in such a way that it stays stuck producing a continuous voltage above 0.5 Volts (500 millivolts).
- A Rich condition due to a:
- High fuel pressure.
- Leaking fuel injectors.
- Bad fuel pressure regulator (this bad boy is part of the fuel pump assembly on Dodge/Jeep vehicles covered in this tutorial).
- EVAP canister vacuum hose leaking fuel into the intake manifold.
- A throttle position sensor (TPS) that is failing intermittently.
- PCM not getting the correct signal due to a short in the O2 sensor's wiring.
- This usually the end result of the O2 sensor's wiring or the engine wiring harness coming into contact with the exhaust pipe, exhaust manifold or a hard edge (usually on the engine) that causes wiring's insulation starts to melt.
- Bad PCM. This is extremely rare.
With this basic info we can now start troubleshooting the P0132 DTC, let's turn the page and get testing.