(2) codes P0090, P0171...any ideas

2003.5_MSP

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2003.5 MSP
Hey just wanting some help on the P0090 code... I figured that the to lean could be the crack in my turbo mani... But I guess my question is are those two codes related? I did a little research and found out that it code possibly be a dirty fuel filter, fuel pump, and or a fuel regulator... Am I on the right track with this code or do you guys think it's something else... Thanks
 
Hey just wanting some help on the P0090 code... I figured that the to lean could be the crack in my turbo mani... But I guess my question is are those two codes related? I did a little research and found out that it code possibly be a dirty fuel filter, fuel pump, and or a fuel regulator... Am I on the right track with this code or do you guys think it's something else... Thanks
the code p0090 is NON-EXSISTANT according to alldata and for your 171 code its saying there COULD possibly be an issue with your MAF
182006527

91164219

91164220


hope that helps ill log into the Mazda support system and look up the p0090... for all i know it could be a Manufacturer code only and alldata does NOT show it... 0.o
 
Hey just wanting some help on the P0090 code... I figured that the to lean could be the crack in my turbo mani... But I guess my question is are those two codes related? I did a little research and found out that it code possibly be a dirty fuel filter, fuel pump, and or a fuel regulator... Am I on the right track with this code or do you guys think it's something else... Thanks

P0090
PRC solenoid valve circuit malfunction
OFF

2
CCM

(See DTC P0090 [FS])

DTC P0090
Pressure regulator control (PRC) valve circuit malfunction

DETECTION CONDITION
PCM monitors input voltages from PRC solenoid valve. If voltage at PCM terminal 95 remains low or high, PCM determines that PRC solenoid valve circuit has malfunction.

Diagnostic support note
This is a continuous monitor (CCM).

PCM detects the above malfunction condition in two consecutive drive cycles.

PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.

FREEZE FRAME DATA is available.

DTC is not stored in PCM memory.

POSSIBLE CAUSE
PRC solenoid valve malfunction

Connector or terminal malfunction

Short to ground in wiring between PRC solenoid valve terminal B and PCM terminal 95

Open circuit in wiring between main relay terminal D and PRC solenoid valve terminal A

Open circuit in wiring between PRC solenoid valve terminal B and PCM terminal 95

Short to power circuit between PRC solenoid valve terminal B and PCM terminal 95

PCM malfunction

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Diagnostic procedure


STEP
INSPECTION
ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
Has FREEZE FRAME DATA been recorded?
Yes
Go to next step.

No
Record FREEZE FRAME DATA on repair order, then go to next step.

2
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
Check for related Service Bulletins availability.

Is any related repair information available?
Yes
Perform repair or diagnosis according to available repair information.

If vehicle is not repaired, go to next step.

No
Go to next step.

3
CLASSIFY INTERMITTENT CONCERN OR CONTINUOUS CONCERN
Clear DTC from memory using WDS or equivalent.

Turn ignition key to OFF then Start engine.

Is PENDING CODE of same DTC present?
Yes
Go to next step.

No
Refer to intermittent concern.

(See INTERMITTENT CONCERN TROUBLESHOOTING [FS].)

4
CLASSIFY OPEN CIRCUIT OR SHORT TO GROUND MALFUNCTION
Disconnect PRC solenoid valve tube that connects to intake manifold.

Connect vacuum pump to PRC solenoid valve.

Apply vacuum and wait 5 seconds.

Is vacuum maintained?
Yes
Go to Step 6.

No
Go to next step.

5
INSPECT PASSAGE CONTROL OF PRC SOLENOID VALVE
Turn ignition key to OFF.

Disconnect PRC solenoid valve connector.

Is vacuum maintained?
Yes
Repair or replace harness between PCM terminal 95 and PRC solenoid valve terminal B for short to ground, then go to Step 11.

No
Replace PRC solenoid valve, then go to Step 11.

6
INSPECT PRC SOLENOID VALVE CONNECTOR FOR POOR CONNECTION
Turn ignition key to OFF.

Check for poor connection (damaged/pulled-out pins, corrosion, etc.).

Is there malfunction?
Yes
Repair or replace terminal, then go to Step 11.

No
Go to next step.

7
INSPECT PRC SOLENOID VALVE
Measure resistance between PRC solenoid valve terminals (part-side).

Is resistance within 22 26 ohms?
Yes
Go to next step.

No
Replace PRC solenoid valve, then go to Step 11.

8
INSPECT PRC SOLENOID VALVE POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT
Turn ignition key to ON (Engine OFF).

Measure voltage between PRC solenoid valve terminal A (harness-side) and body ground.

Is voltage B+?
Yes
Go to next step.

No
Repair or replace harness for open, then go to Step 11.

9
INSPECT PCM CONNECTOR FOR POOR CONNECTION
Turn ignition key to OFF.

Disconnect PCM connector.

Check for poor connection at terminal 95 (damaged/pulled-out pins, corrosion, etc.).

Is there malfunction?
Yes
Repair terminal, then go to Step 11.

No
Go to next step.

10
INSPECT PRC SOLENOID VALVE CONTROL CIRCUIT
Connect breakout box with PCM disconnected.

Turn ignition key to ON (Engine OFF).

Measure voltage between PRC solenoid valve terminal B (harness-side) and body ground.

Is voltage B+?
Yes
Repair or replace harness for short to power, then go to next step.

No
Check for continuity between PRC solenoid valve terminal B (harness-side) and breakout box terminal 95.

If there is continuity, go to next step.

If there is no continuity, repair or replace harness for open, then go to next step.

11
VERIFY TROUBLESHOOTING OF DTC P0090 COMPLETED
Make sure to reconnect all disconnected connectors.

Clear DTC from memory using WDS or equivalent.

Turn ignition key to OFF then start engine.

Is PENDING CODE of same DTC present?
Yes
Replace PCM, then go to next step.

No
Go to next step.

12
VERIFY AFTER REPAIR PROCEDURE
Perform After Repair Procedure.

(See AFTER REPAIR PROCEDURE [FS].)

Is there any DTC present?
Yes
Go to applicable DTC inspection.

(See DTC TABLE [FS].)

No
Troubleshooting completed.
 
the code p0090 is NON-EXSISTANT according to alldata and for your 171 code its saying there COULD possibly be an issue with your MAF
hope that helps ill log into the Mazda support system and look up the p0090... for all i know it could be a Manufacturer code only and alldata does NOT show it... 0.o

My dads scan tool read the car and came up with the P0090 code, it was something to do with some sort of circuit fuel control valve?
I did awhile back have a MAF low input/output code.. but i cleaned it with MAF cleaner and it hasnt came back... my turbo mani also has cracks in it so that is also contributing to the 171 code..
 
hte crack wouldnt contribute to that, it would just make it boost slowly. ....

unfortunatley,, i work at a mazda dealership.
 
So sounds like my PCM is bad? Bc the code reader said something like fuel trim... And if that's bad that would through the lean code I'm having correct?
 
Nope no ssafc here... Just outta curiosity why would a ssafc cause a CEL?

possibly because its taking the stock signals from the maf and the o2 sensor and changes them so the computer might sense the difference as a problem...maybe?
 
hmm well Ill just have make sure that I put in my ssafc correctly then with no leaks, when I get it...
 
when i installed my ssafc, i didnt get any codes with the superstock tune, i got a few codes when i entered to lean or to rich values and when my o2 sensor failed, but besides that, i have had no issues with ssafc throwing codes
 
when i installed my ssafc, i didnt get any codes with the superstock tune, i got a few codes when i entered to lean or to rich values and when my o2 sensor failed, but besides that, i have had no issues with ssafc throwing codes

phewww, that kinda was deturing me away from ssafc, but now tou say that im back to getting one...
 
For the p0171 code it talks about the purge solenoid valve possible being bad. In tech manual it says that across the two terminals that I should get continuity. I just want to confirm that that is correct. Mine is open. I think that could be my problem.

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