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2005 Ford Focus P0106, P0400, P0452, P0191, and P0300 Codes - Diagnosis and Fixes

Model: 2005 ford focus Fault Code: P0106 Posted: 2014-03-19 12:39

My 2005 Ford Focus is showing multiple OBD-II diagnostic trouble codes: P0106, P0400, P0452, P0191, and P0300. The vehicle runs smoothly under normal conditions, and I can clear the codes using a scanner — however, the P0452 code returns almost immediately. I'm looking for reliable explanations or troubleshooting steps to address these issues. Any insights into whether these codes are related or if one is causing the others would be greatly appreciated.

Related fault codes
P0106P0300P0400P0452
Comments (9)
Anonymous 2014-03-21 18:08

P0452 - Ford Description: The Evaporative Emission System (EVAP) control system pressure sensor monitors pressure in the purge line. As pressure increases, the sensor's output voltage to the Engine Control Module (ECM) rises. This sensor is used solely for diagnostic purposes and does not directly control engine operation. Possible Causes: - Faulty EVAP pressure sensor - Open or shorted EVAP pressure sensor harness - Poor electrical connection in the EVAP pressure sensor circuit

Anonymous 2014-03-21 19:33

Could any of these codes — such as P0106, P0400, P0191, or P0300 — be directly related to the P0452 code or caused by it?

Anonymous 2014-03-22 11:48

It's a tough call, but I'd say they are likely not directly related. Vehicle history matters — has this been a stock model with no major repairs? Any recent modifications or work done on the fuel system or emissions components could influence these codes.

Anonymous 2014-03-22 11:52

What would be the best first step to diagnose and resolve these issues?

Anonymous 2014-03-22 12:11

Could vehicle history help? Is this a stock 2005 Ford Focus with no major repairs? Also, what tools do you have — such as an OBD-II scanner, digital multimeter (DVOM), test light, or wiring diagrams?

Anonymous 2014-03-22 13:55

The vehicle is stock. I do have access to a reliable OBD-II scanner.

Anonymous 2014-03-22 14:26

The P0452 code relates to the fuel tank pressure sensor — check for wiring issues at the sensor, such as an open circuit or poor voltage connection. Also, consider whether any past repairs (e.g., fuel pump replacement) might be contributing, especially since both P0191 and P0400 are tied to fuel system performance.

Anonymous 2014-03-28 22:43

My 2001 Ford Focus shows 'noSUP' and '0dec' — what do these codes actually mean?

Anonymous 2014-03-29 08:14

Those are likely invalid or corrupted codes. You may want to start a new thread for that specific issue.