2008 Saturn Vue XE 2.4L Error Codes
 

I cannot seem to find the problems related to several error codes. I am getting the following errors on this 2008 Saturn Vue XE 2.4L .

• P0442 small evap leak,
• P0451 problem with the Evaporative Emission System Pressure Sensor,
• P0496 indicates a problem with the Evaporative Emission (EVAP) system, specifically meaning that there is "high purge flow during a non-purge condition", which translates to too much air flowing into the charcoal canister when it shouldn't be, potentially causing excessive fuel vapors to reach the engine ,
• P0454 Evaporative Emission System Pressure Sensor/Switch Intermittent.” EVAP fuel tank pressure is monitored by your PCM using an EVAP pressure sensor,
• P0464 a problem with the Fuel Level Sensor. This sensor is directly responsible for the dash fuel gauge, so when faulty, it will create the symptoms you describe here. On this vehicle, the level sensor is in fact, built into the body of fuel pump assembly,
• P0455 a "gross leak" in the vehicle's Evaporative Emission Control (EVAP) system, meaning there is a significant leak somewhere in the system responsible for capturing fuel vapors, most commonly caused by a loose or damaged gas cap, cracked hoses, or a faulty purge valve.
• P2138 indicates a problem with the throttle pedal position sensor, specifically that the voltage signals from the two sensors within the pedal are not correlating properly, meaning the car's computer cannot accurately determine the accelerator pedal position, potentially causing issues like reduced throttle response or a check engine light.
• C0561-71 indicates a problem with the brake booster vacuum sensor, specifically related to a communication issue between the Electronic Brake Control Module (EBCM) and other vehicle systems, causing a discrepancy in data received regarding the braking system's status.
• C0035 indicates a problem with the right front wheel speed sensor, specifically related to its electrical supply circuit, meaning there might be an issue with the sensor itself, its wiring, or the connection to the ABS module.

Anyone know how to find the specific part that is causing these errors? I have changed out the purge valve under the hood and also the front drivers side wheel speed sensor, but the errors returned after I erased all the codes.
.

Okay I will take first stab at this.

The fuel pressure sensor I believe is in the gas tank on this vehicle, but don't quote me on that. That covers the two errors related to the fuel pressure sensor. Since it is measuring the pressure of the entire fuel system, that may explain why it is purging when it is not supposed to be doing so, because it is getting incorrect signals from the fuel pressure sensor which are telling the PCM to open the purge valve. But there is another part of the PCM that is looking at the fuel pressure sensor readings saying hey this is crap.

Small evap leak is often the seal on your gas cap. Replace with an OEM cap not aftermarket and see if that helps.

Gross evap leak can be anywhere. I was wondering if maybe your vent valve was stuck partially open, but this usually throws a code by itself so it may be elsewhere.

The antilock speed sensors and or the tone rings on the half axles can accumulate little shards of magnetic material which stick usually to the face of the sensor itself. However, the tone ring is also magnetic and in theory can also collect magnetic shards or just be caked with dirt. Inspect the tone ring for damage.

Throttle body position sensors on this vehicle, I don't know, but someone else hopefully will join in the discussion plus there are posts out there specifically addressing 2138

Brake booster vacuum communication? Can't help you with that one.

Note that most of these codes may also be triggered by damaged/broken wiring.

Thank you, Derf
 

Hello Derf. Thank you for the information. I previously replaced the purge valve and have ordered a pressure sensor. Changed the gas cap couple of years ago when I started to get evap errors.

Similar situation for me on 2.4L 2008 Vue XE. Lot of codes. Took to shop months ago and they stated I needed to replace all 4 wheel speed sensors. No way. Too coincidental.
I currently have the following codes and suspect electrical issue.
C0035 - Rt Front Wheel Speed Sensor Supply
C0050 - Rt Rear Wheel Speed Sensor Supply
C0899 - Device #1 Voltage Low
P0010 - CMP actuator intake circuit malfunction
P0042 - Small Evap Leak

Over the last several months I have also had C0040 and C0045 for left wheel speed sensors.
The P0442 may be a small vacuum leak somewhere. Shop threw a fuel cap at it - no change.

I am not electrically savvy but I was able to check the intake CMP solenoid resistance. It was 12.2. Range should be 8 - 12. Is 12.2 bad or is this just instrument variation?
I have looked numerous times for broken wires but cannot find any. Wire looms cracking all over the place in the engine bay.
Warning lights on all the time are: 2 TSC lights, 1 ABS light, 1 Low tire pressure light, CEL. The brake light comes on for a few days, then goes away. Has been off now for weeks.
Tire pressure is good. Another reason I suspect wiring issue.

I have monitored via scan tool the voltage. While driving voltage reaches 15 V.

Any ideas on where to look would be appreciated. Especially if you have any photos to demonstrate where.
Thanks,
James

How many miles on the vehicle?

Each of the wheel speed sensors are powered through their own external power pins on the ebcm and return wires are grounded at the electronic brake control module (EBCM).on different pins. The 5 volt source for each of the wheel speed sensors also comes from the EBCM. Some of the things that can lead to improper wheel speed sensor signals are metallic magnetic shards that have accumulated on the end of the speed sensor and are interfering with the signal generated by the tone wheel as it passes the sensor. Other causes include corrosion on the connector harness, the sensor pins which connect to the harness. Additionally, since these vehicles have their wheel speed sensors integral to the wheel hubs, worn bearings can lead to incorrect or erratic signals from the sensors because of the play.

The fact that the left side signals came and went is strange. All of the wheel speed sensors share the five volt signal supplied by the EBCM and the internal ground supplied by the EBCM.

Did all of the wheel speed sensor codes show up at exactly the same time? Or was it a progression? And when they showed up, was it all 4 or just the right side?

The responses will help us narrow it down. You can check for corrosion on the connectors in the meantime.
Here is a link to the circuit I'm working off of

/https://charm.li/Saturn/2008/VUE%20F...rol%20Systems/

156k miles. Took possession of the vehicle last July from my mother-in-law. First code reading showed all 4 wheel speed sensors. Since then I've also seen P1877 and C0196. I've cleared codes more than once. Only codes now are those in my first message.
To check the sensors, the tires must be removed, correct? Or can they be accessed and cleaned with tires on? Thanks.

Are you talking about the tire pressure sensors? If so, the tires have to be broken down to access them. They run on batteries and over time the batteries DO die. At 18 years old, I suspect that they all need replacing by now. If you're not talking about the tire pressure sensors, then I apologize. My wife died a couple of months ago and I'm still kind of effed up about that. I can't think straight.

Condolences on your loss.
The sensors I am asking about are the wheel speed sensors for inspection and cleaning. Looks like I will have to remove the tires to access them.

Apologies for the delay. Indeed you will need to remove each wheel to access the corresponding wheel speed sensor located in the hub

I removed the right front wheel and unclipped the wheel speed sensor. Internally looked fine. Could not see where the sensor actually is.
Seems I have to remove the brake rotor as well?