: P0171 & P0174



VilleBilly
01-08-07, 11:11 AM
Initially had P0335 with stalling. Had my mechanic change both CKP Sensors and seems to have fixed the stalling. Now I get P0171 & P0174 after longer drives of 20 -30 miles. Does not occur on quick around the corner drives. Did not happen until after the CKP sensor change. Looked, cant find and dont think it's a vacuum leak. Any thoughts?

Cad tech
01-10-07, 08:52 PM
I need to know what year and model and or just vin please mainly for 9 or Y engine, but here is some infor to get you started....



DTC P0171 or P0174
Circuit Description
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open Loop and Closed Loop. During Open Loop, the PCM determines fuel delivery based on sensor signals, without oxygen sensor input. During Closed Loop, the PCM adds oxygen sensor inputs to calculate short term and long term fuel trim, fuel delivery adjustments. If the oxygen sensors indicate a lean condition, fuel trim values will be above 0 percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0 percent. Short term fuel trim values change rapidly in response to the HO2S voltage signals. Long term fuel trim makes coarse adjustments in order to maintain air/fuel ratio of 14.7:1. If the PCM detects an excessively lean condition, this DTC will set.

Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0107, P0108, P0121, P0122, P0123, P0130, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0401, P0403, P0404, P0405, P0410, P0440, P0442, P0446, P0506, P0507, P1404, P1441 are not set.
The engine coolant temperature (ECT) is between 20-110C (68-230F).
The intake air temperature (IAT) is between -18 to +76C (-4 to +168F).
The manifold absolute pressure (MAP) is between 15-85 kPa (2.1-12.3 psi).
The vehicle speed is less than 132 km/h (82 mph).
The engine speed is between 575-4,000 RPM.
The barometric pressure (BARO) is more than 70 kPa (10.1 psi).
The mass air flow (MAF) is between 3-85 g/s.
The fuel level is more than 10 percent.
Conditions for Setting the DTC
The average long term fuel trim value is above 23 percent.

All of the above conditions are present for 6 seconds.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
The system will go lean if an injector is not suppling enough fuel.
The system will go lean during high fuel demand.
Using a scan tool, review the Failure Records. If an intermittent condition is suspected, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.

If no problem was found, refer to Fuel System Diagnostics for a possible fuel problem.

If no problems are found, a worn cam, worn intake or exhaust values or other engine mechanical failures may be at fault.

This mainly deals with the B1S1 and B2S1 o2 and since you just got the CKP sensors replaced he may have pulled wires to the O2 (common) bring it back to him now and tell hium it was not on before and how soon it came on after the prior repair.....

VilleBilly
01-11-07, 01:49 PM
cad tech, my car is a 2000 ESC (VIN 1G6EL12Y7YU133996). I also have code RFA U1000 that always returns even when cleared, but only when i get another code. I dont believe that i have seen this code by itself, but when i had the previous P0335 for the CKP sensor and the current 171 & 174 it is always there. I did not go to the dealership for last replacement of the CKP sensors and i am losing confidence in my mechanic. Thank you very much.

Cad tech
01-11-07, 02:22 PM
rfa code is of factor it is for remote module and just a com code no worries

you need to do an injector leakdown test and check for vacuum leaks

your RFA code constists;

DTC B1000 RFA Internal Fault (Self Test Failed)

Circuit Description
The remote function actuator (RFA) module performs a self test on its internal memory when the ignition switch is cycled from OFF to ON.

Conditions for Setting the DTC
The RFA module fails the internal read only memory (ROM) to random access memory (RAM) write test.

Action Taken When the DTC Sets
A DTC B1000 is stored in the RFA module memory.

No driver warning message is displayed for this DTC.

Conditions for Clearing the DTC
The RFA module passes the self test after the ignition is cycled from OFF to ON.
The ignition must be cycled from OFF to ON before the DTC changes from current to history.
Diagnostic Aids
The DTC will show a test not passed since last cleared on the scan tool.
The ignition must be cycled from OFF to ON before the DTC changes from current to history.

FrankT
01-11-07, 06:38 PM
when i had the previous P0335 for the CKP sensor and the current 171 & 174 it is always there. I did not go to the dealership for last replacement of the CKP sensors and i am losing confidence in my mechanic. Thank you very much.

Don’t be too fast in losing confidence in your mechanic just yet. Sometimes certain codes disable or keep other codes from running. The crank sensor code may have kept the fuel trim codes from running and setting.

How did you check for vacuum leaks?

Now, as far as your lean DTCs, your engine is running lean on both banks, so I would start by looking for something common to both banks, such as vacuum leaks at the intake manifold, air induction system, and air intake ducts. Also check crankcase ventilation system for leaks.

Try using a can of carb spray while observing for engine speed changes.
You can also remove the MAF sensor and clean the elements, be very gentle with them. The MAF sensor elements can get a silt build up on them, this condition will cause a lean fuel mixture too.

Keeps us posted
Frank

Cad tech
01-12-07, 11:45 AM
crank sensor codes or problems do not disable 02 codes or make it stay in open loop, so in fact the 2 have no contributing factors to each other...
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0107, P0108, P0121, P0122, P0123, P0130, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0401, P0403, P0404, P0405, P0410, P0440, P0442, P0446, P0506, P0507, P1404, P1441 are not set.
The engine coolant temperature (ECT) is between 20-110°C (68-230°F).
The intake air temperature (IAT) is between -18 to +76°C (-4 to +168°F).
The manifold absolute pressure (MAP) is between 15-85 kPa (2.1-12.3 psi).
The vehicle speed is less than 132 km/h (82 mph).
The engine speed is between 575-4,000 RPM.
The barometric pressure (BARO) is more than 70 kPa (10.1 psi).
The mass air flow (MAF) is between 3-85 g/s.
The fuel level is more than 10 percent.
Conditions for Setting the DTC
The average long term fuel trim value is above 23 percent.

look at above posts by me and check for intake leaks, injector o-ring leakc ect..