In all Ford cars, you’ll find four O2 sensors. The 4-wire Ford O2 sensor wire colors may differ based on its position (driver or passenger side). To replace these wires, you will need the 4 wire ford o2 sensor wiring diagram.
In this guide, I’ll share wiring harness details of Ford’s four-wire oxygen sensor diagram along with insights on their color. Keep on reading…
Table of Contents
Ford 4 Wire O2 Sensor Wiring Diagram
Most of the time, Ford cars come with three or four 4-wire O2 sensors that connect to different systems based on the working.
According to the Automotive Troubleshooting Secrets, the 4 wires of the O2 sensor can be sorted into two groups. Which are:
- Heater Wires: These keep the sensor warm so that it operates nonstop. There are two of them, and their job is to make sure the sensor stays heated.
- Power Wires: These are like the energizers. There are also two of these wires, and they do two things. First, they send signals to the car’s system, telling it about the oxygen level in the exhaust. Plus, they give power to the system so it can do its job properly.
To check or repair the wires, it’s vital to know which cable goes where in order to keep the sensor working. For that, be sure to first know the O2 sensor location. In case you don’t know it, here’s the detail:
Ford 4-wire O2 sensor wiring diagram
| Pin Number of Wire | Wire Function | Connectors To |
| 1 | Heater (Power) | PCM power relay in power distribution fuse box |
| 2 | Heater (Ground) | PCM (fits on O2 heated control terminal) |
| 3 | Sensor Ground | PCM (fits on sensor ground terminal) |
| 4 | O2 Signal | PCM (fits on O2 signal terminal) |
Ford 4 Wire O2 Sensor Wiring Diagram Details
If you are confused, let me explain the wiring connection of the above diagram. The heater (power) wire is connected to Pin 1 of the O2 sensor. This wire links to the PCM power relay located within the power distribution fuse box.
Then, the heater (ground) wire that goes in the Pin 2. This wire fits to the PCM (onto the O2 heated control terminal).
Moving on to the sensor ground wire that goes in the Pin 3, also connects to the PCM. But this wire connects to the sensor ground terminal. Finally, the O2 signal wire that goes in Pin 4, links to the PCM (onto the O2 signal terminal).
4 Wire Ford O2 Sensor Wire Colors!
Ford cars usually come with 4 oxygen sensors with 4 wiring harnesses. All four sensors have diverse wiring harness color code that depends on placement. Let me break it down below so you can easily know it all:
Ford 4 Wire O2 Sensor on the Driver Side
On the driver side, you’ll see 2 oxygen sensors containing diverse wiring harnesses. Based on the O2 sensor position, the wire color will vary. Here’s what I mean:
| O2 Sensor Location | Pin 1 Wire Color | Pin 2 Wire Color | Pin 3 Wire Color | Pin 4 Wire Color |
| (21) on the upper of the engine exhaust pipe | Red or yellow | Yellow or light blue | Gray or red | Red or black |
| (22) on the bottom of the engine exhaust pipe | Violet or white | Tan or yellow | Gray or red | Violet or light green |
Ford 4 Wire O2 Sensor on the Passenger Side
On the passenger side, you’ll see 2 oxygen sensors that have different wiring harnesses. Depending on the O2 sensor position, the wire shade will differ. Let me break it down:
| O2 Sensor Location | Pin 1 Wire Color | Pin 2 Wire Color | Pin 3 Wire Color | Pin 4 Wire Color |
| (11) on the upper of the engine exhaust pipe | Red or yellow | Red or white | Gray or red | Gray or light blue |
| (12) on the bottom of the engine exhaust pipe | Violet or white | white or black | Red or light green | Gray or red |
Ending Notes
Now that you know the 4-wire Ford O2 sensor wire colors along with the drawing details, it’ll be easier to change or repair the cables.
Just ensure to inspect the condition first before you do anything. And, always be careful when you do so by wearing safety equipment and using tools.
Hope this guide helps you to know the wiring shade and illustration to understand which wire goes where. If you’d like some more feeds on O2 sensors, go check my other guide that talks about the number of o2 sensors that a Ford F150 vehicle uses.
See You with a New Guide Soon!
