Fuel rail pressure sensor issue on a 2009 Ford Ranger TDI?

Ford Models Forum Ford Ranger Club
1

Hi all, I’m working on a 2009 Ford Ranger 3.0 TDI and can’t seem to detect the fuel rail pressure sensor. The 5V reference voltage is reading only 1.3V. I’ve swapped the sensor with a known good one, but the issue persists. I’ve also tested the lockset in another vehicle, and it works perfectly. What could be causing this voltage drop?

2

If the 5V reference is only showing 1.3V, it’s probably a wiring issue. Check for damaged wires, poor connections, or a short circuit. The ground connection could also be affecting the voltage.

3

Winslow said:
If the 5V reference is only showing 1.3V, it’s probably a wiring issue. Check for damaged wires, poor connections, or a short circuit. The ground connection could also be affecting the voltage.

Agreed. I had a similar issue, and it turned out to be a grounding problem. Cleaned up the ground point, and it fixed the voltage issue.

4

@Victoria
Thanks for the tip. I’ll check the grounds first thing tomorrow.

5

The sensor connects directly to the PCM. Have you checked if the PCM is supplying the proper voltage? If not, it might be a fault in the PCM itself.

6

Chase said:
The sensor connects directly to the PCM. Have you checked if the PCM is supplying the proper voltage? If not, it might be a fault in the PCM itself.

Good point. If the PCM isn’t outputting 5V, there might be an internal issue or software problem.

7

Here’s what I know: the fuel rail pressure sensor has three pins, and they’re connected to PCM pins 109, 140, and 191. The PCM supplies the 5V directly. Have you traced the wiring from the PCM to the sensor?

8

@Vincent
I haven’t checked that yet, but I’ll give it a go. Any advice on what to look for specifically?

9

If you want to test the sensor, you can temporarily supply 5V from another source. Just make sure the ground is solid and there aren’t any shorts. Then check if the sensor communicates with the PCM.

10

Rosalie said:
If you want to test the sensor, you can temporarily supply 5V from another source. Just make sure the ground is solid and there aren’t any shorts. Then check if the sensor communicates with the PCM.

Thanks for the suggestion. I’ll try that and report back if it works.