Generic OBDII P Code List: P0001-P0099

Learn the definitions and the most common causes for Generic OBDII P Codes P0001-P0099

This post lists the most common trouble codes in the OBDII P Codes P0001-P0099 category. Start by reading the most common codes and causes and then refer to the code chart at the end of the post for official code definitions.

I’ll start by discussing the most common Trouble codes in this group, along with the most common causes of those codes.

How to find your code definition

There are 192 001-099-series codes. There are several ways to find the code definition in the chart below.
1) Enter the trouble code in the search box. That’s the fastest way
2) If you’d like to scroll all the codes, change the Number of entries to show on the page in “Show Entries” box. Click NEXT or PREVIOUS at the bottom right of the table

The most common trouble codes in the P0001-P0099 category

1) P0010-P0019 codes relate to camshaft timing. In a variable

Camshaft phaser for variable valve timing

valve timing engine, camshaft timing is usually accomplished by advancing or retarding a camshaft phaser. The phaser is mounted on the front of the camshaft and contains oil chambers. As the ECU determines the need for advanced or retarded camshaft timing, an oil control solenoid pulses pressurized engine oil into the chambers or releases oil pressure from the chambers of the phaser.

Common causes of P0010-P0019 codes

The ECU knows how long each oil pulse should be based on engine and oil temperatures. In my experience the most common causes for these codes are the wrong oil viscosity and oil change neglect. The wrong oil viscosity causes an incomplete fill of the phaser chambers or a delay in emptying the chambers. Oil change neglect causes sludge buildup and clogging of the oil control solenoid screens. That results in a camshaft timing that differs from the ECU’s commanded timing.

Diagnose P0010-P0019 codes

• Check oil level and condition
• Check for the proper oil filter. The wrong oil filter or a clogged oil filter can result in a mismatch between commanded cam timing and actual.
• Check for sludge buildup in the solenoid screens or faulty oil control solenoids. Clean or replace as necessary
• Check for excessive timing chain tension
• Check for faulty camshaft position sensor adjustment

Sludge in VVT oil control solenoid screen

2) P0030-P0038 Oxygen sensor heater codes

Oxygen sensors can’t properly read oxygen levels in the exhaust stream until they reach about 600 degrees Fahrenheit. Exhaust gasses can heat them up, but in cold weather, they can cool below optimal operating temperatures. Carmakers bypass this problem by installing an electric heater inside each oxygen sensor.

Oxygen sensor heater codes can be caused by a bad sensor or by a blown fuse or wiring harness issue in the heater circuit

The most common mistake DIYers make when they see these codes is to assume that the oxygen sensor is bad. Before replacing an oxygen sensor due to a heater code, you should disconnect the electrical connector from the sensor and make sure the heater is getting power and ground. If you’re not seeing power and ground, the problem could be a blown fuse or a wiring harness issue. If you simply replace the oxygen sensor without checking for power and ground, you may waste money

P0001-P0099 are related to Fuel and Air Metering
Here, you’ll find codes for components that relate to air/fuel ratio

©, 2024 Rick Muscoplat