Bought 2018 Mirage with SRS & check engine light for EVAP

[yusha1]

I bought a 2018 Mirage g4 has the SRS and Check engine lights on.
The Check Engine light:
P0452 EVAP Emission Prs Sensor Low Input
P0441 EVAP Emission Purge Flow
P0450 EVAP Emission Pressure Sensor
P0137 Oxygen Sensor Low B1S2
So checking this out, I did not find any carbon filter box. Pulling the device itself I tested it and unit is working... I blew in the hose from gas tank- it seems to go whole way to tank. When letting go got a whiff of gas fumes and air coming back. The other hose comes from air intake. I cleaned the gas cap, tried a different one, tore the seat out and checked the hoses/ fittings and caps for tank. Nothing broken or cracked.



Airbag light:
B1429 Right Front Side Impact Sensor Communication Impossble
B1479 Back up Capacitor Terminal Low Voltage- Active DTC
To clarify, this car obviously has body damage to the back and front driver side bumper, also back driver side panel.- so there was a wreck at sometime. The problem here is that the airbag sensors in the front. When i checked the codes, scanner tool said it cannot communicate with front right sensor - NOT the left (Driver side which has damage) I figured the sensor needs to be changed and computer reset- ordered a sensor, plugged in and shop did reset. Guy then tells me its a hard fault and it is coming back still saying the same- cannot communicate with front right sensor. Took off the battery cable, changed sensors around, ran the scanner, tried to reset, same issue. Cannot communicate with front right sensor. So I tested the harness voltage, shows 5 volts. I'm honestly confused, after talking to a mechanic in auto parts place he was telling me it sounds like a computer issue. I ordered a computer, only to find out it has corrosion on the board and damaged components.
Has anyone had similar issue? Any clues to fix?

[mohammad]

I bought a 2018 Mirage g4 has the SRS and Check engine lights on.
The Check Engine light:
P0452 EVAP Emission Prs Sensor Low Input
P0441 EVAP Emission Purge Flow
P0450 EVAP Emission Pressure Sensor
So checking this out, I did not find any carbon filter box. Pulling the device itself I tested it and unit is working... I blew in the hose from gas tank- it seems to go whole way to tank. When letting go got a whiff of gas fumes and air coming back. The other hose comes from air intake. I cleaned the gas cap, tried a different one, tore the seat out and checked the hoses/ fittings and caps for tank. Nothing broken or cracked.
Airbag light:
B1429 Right Front Side Impact Sensor Communication Impossble
B1479 Back up Capacitor Terminal Low Voltage- Active DTC
To clarify, this car obviously has body damage to the back and front driver side bumper, also back driver side panel.- so there was a wreck at sometime. The problem here is that the airbag sensors in the front. When i checked the codes, scanner tool said it cannot communicate with front right sensor - NOT the left (Driver side which has damage) I figured the sensor needs to be changed and computer reset- ordered a sensor, plugged in and shop did reset. Guy then tells me its a hard fault and it is coming back still saying the same- cannot communicate with front right sensor. Took off the battery cable, changed sensors around, ran the scanner, tried to reset, same issue. Cannot communicate with front right sensor. So I tested the harness voltage, shows 5 volts. I'm honestly confused, after talking to a mechanic in auto parts place he was telling me it sounds like a computer issue. I ordered a computer, only to find out it has corrosion on the board and damaged components.
Has anyone had similar issue? Any clues to fix?

have you checked for continuity in the airbag sensor wires? maybe they were broken in the crash?

[Fummins]

I bought a 2018 Mirage g4 has the SRS and Check engine lights on.
The Check Engine light:
P0452 EVAP Emission Prs Sensor Low Input
P0441 EVAP Emission Purge Flow
P0450 EVAP Emission Pressure Sensor
So checking this out, I did not find any carbon filter box. Pulling the device itself I tested it and unit is working... I blew in the hose from gas tank- it seems to go whole way to tank. When letting go got a whiff of gas fumes and air coming back. The other hose comes from air intake. I cleaned the gas cap, tried a different one, tore the seat out and checked the hoses/ fittings and caps for tank. Nothing broken or cracked.
Airbag light:
B1429 Right Front Side Impact Sensor Communication Impossble
B1479 Back up Capacitor Terminal Low Voltage- Active DTC
To clarify, this car obviously has body damage to the back and front driver side bumper, also back driver side panel.- so there was a wreck at sometime. The problem here is that the airbag sensors in the front. When i checked the codes, scanner tool said it cannot communicate with front right sensor - NOT the left (Driver side which has damage) I figured the sensor needs to be changed and computer reset- ordered a sensor, plugged in and shop did reset. Guy then tells me its a hard fault and it is coming back still saying the same- cannot communicate with front right sensor. Took off the battery cable, changed sensors around, ran the scanner, tried to reset, same issue. Cannot communicate with front right sensor. So I tested the harness voltage, shows 5 volts. I'm honestly confused, after talking to a mechanic in auto parts place he was telling me it sounds like a computer issue. I ordered a computer, only to find out it has corrosion on the board and damaged components.
Has anyone had similar issue? Any clues to fix?

There is a purge solenoid on the drivers side of the cylinder head. The vent solenoid is at the back on the charcoal canister. I've seen the purge solenoid fail in the open position throwing codes(I can't remember which one(s)). You might want to check that out. I think the pressure sensor is mounted to the top of the fuel pump housing. Some people have had the wires chewed up leading to the fuel pump assembly.

As for the airbag light...
On certain vehicles, the Supplemental Restraint System (SRS) Air Bag Warning Lamp illuminates with DTC B1479 (SRS-ECU Backup capacitor circuit voltage too Low.)
When the battery voltage becomes low, the back up capacitor's diagnosis function may judge
backup capacitor failure and set DTC B1479. The SRS-ECU must be replaced due to the incapability
to erase DTC B1479 via MUT-III.
This TSB instructs dealers to reprogram the SRS-ECU with updated software to correct the issue.

https://static.nhtsa.gov/odi/tsbs/20...48753-9999.pdf

[yusha1]

have you checked for continuity in the airbag sensor wires? maybe they were broken in the crash?

I only have a cheap multimeter so no, besides the voltage reading. I checked the contacts on harness, got 5 volts. Even tried moving wire around to see if theres maybe a break but no drop at the meter.

There is a purge solenoid on the drivers side of the cylinder head. The vent solenoid is at the back on the charcoal canister. I've seen the purge solenoid fail in the open position throwing codes(I can't remember which one(s)). You might want to check that out. I think the pressure sensor is mounted to the top of the fuel pump housing. Some people have had the wires chewed up leading to the fuel pump assembly.

I checked the EVAP purge solenoid (Drivers side, kinda tucked away, has two air hoses a connector and single mounting bolt) but didnt find anything wrong with it. I did however realize I'm an idiot last night as I found the charcoal filter is under the trunk. Going to check the hoses on it. As for chewed wires, I didn't see any issues when I pulled the seat out last time.

As for the airbag light...
On certain vehicles, the Supplemental Restraint System (SRS) Air Bag Warning Lamp illuminates with DTC B1479 (SRS-ECU Backup capacitor circuit voltage too Low.)
When the battery voltage becomes low, the back up capacitor's diagnosis function may judge
backup capacitor failure and set DTC B1479. The SRS-ECU must be replaced due to the incapability
to erase DTC B1479 via MUT-III.
This TSB instructs dealers to reprogram the SRS-ECU with updated software to correct the issue.

https://static.nhtsa.gov/odi/tsbs/20...48753-9999.pdf

Thank you for the doc. Is there any tool I can rent or something you recomend to reprogram the srs-ecu? I have it pulled out already.

[Fummins]

I only have a cheap multimeter so no, besides the voltage reading. I checked the contacts on harness, got 5 volts. Even tried moving wire around to see if theres maybe a break but no drop at the meter.




I checked the EVAP purge solenoid (Drivers side, kinda tucked away, has two air hoses a connector and single mounting bolt) but didnt find anything wrong with it. I did however realize I'm an idiot last night as I found the charcoal filter is under the trunk. Going to check the hoses on it. As for chewed wires, I didn't see any issues when I pulled the seat out last time.




Thank you for the doc. Is there any tool I can rent or something you recomend to reprogram the srs-ecu? I have it pulled out already.

If you're gonna try to install a used airbag module you'll need to download some sort of rom(?) file from the original module first, while it's still plugged into the car. Then install the new(or used) module and load the original file into the "new" module. They aren't plug and play in these cars. I tried already. I used an older autel maxisys mini to do this on a Mirage, I can't remember if it was a 2015 or 2017. Being a G4 I don't know if a hatch module would work? I do know that a module from a 2015 will not work in a 2017+ because the 17+ came with 2 extra impact sensors in the rear 1/4 panels.
If you want the updated software you might have to go to a dealer for that. I don't know if that'd be a warranty thing or not? If it's got a repaired status/title then probably not.

Here's a wiring schematic from a 2017 Hatch that might help? Not sure if 18' G4 is the same. srs.pdf
I just re-read your first post. Yeah, the charcoal canister is at the rear.

[MetroMPG]

(Admin note: split discussion to new thread)

[yusha1]

Thank you for making the thread! I spent the last few minutes deciding where to post and getting it ready, then realized its already done. LOL. Bit of an update:
I took off the charcoal filter and used carb cleaner hoping this would solve the issue- upon connecting the battery and running scanner I now have the same codes plus oxygen sensor... I'll add images to main post here to give some better imagery and will be back working on the car next weekend.

[yusha1]

Quick, Small update. I got back yesteray and today was messing with the car earlier. Looking at the sensors I saw this:


Is this black one a cap or a sensor? I tested the right front sensor with multi meter and it has .5 showing for resistance. Woud this black cap be my srs issue?

[yusha1]

Figured I would give an update. Went to the dealership and $93 later found out they don't flash the module, although that's what I paid for. They said I have to replace the srs module. So I'm looking for an online service.

[Fummins]

Odd. So the dealer is telling you your airbags were deployed at one time? They didn’t like the tsb?