2001 3.5L Pathfinder CEL code P0505..ISCV/TPS/PCM/ECM?

[zpmada]

I recently had an independent mechanic clean the battery terminals after fixing a P1320 code. He said take it to a Nissan dealer to fix the P0505 code. The Nissan dealer charged me $120 to "diagnose" my car, but they didn't look into the P0505 code like I had asked. They just said I need fluid changes, a ball joint and cv boot, repack bearings, brake fluid change, pads, and this will cost $2000. They said for P0505 diagnostic I will have to leave the car 4 hours. They said it is possible the previous mechanic did not disconnect the batter in the right sequence which shorted the computer. Is that even possible? I did not have the P0505 before taking it to the first mechanic. Just the P1320 and an O2 sensor code. The next day I get a call asking me if I want to trade in my car for a new one... crooks.

 

It is possible the previous mechanic did not disconnect the battery cables in the right sequence and fried the PCM/ECM/ECU?? Since the dealer was no help, I bought a chilton manual. I checked the resistance on all terminals for the ISCV and I had ~24-~25ohms. The connector going to the ISCV had power so that seems ok.

 

Next I checked the connectors going to the TPS. The orange one was ~5v (fine according to the chilton manual), but the second gray connector didn't show any voltage reading. Where does the power for this gray connector come from? If I don't have power going to the gray connector on the TPS, will that trigger a P0505? Can I open the ECU up and re-solder the TPS circuit myself? Is there a reputable pathfinder ECU rebuilder? Some guy on ebay is charging $200 to take my ECU, rebuild it and mail it back. Is there a guy with a reputation out there if indeed this is my problem?

 

Thanks

[Alkorahil]

I dont understand how they got off on testing the ECU and replacing it and all with a P0505 code, it is just a simple relearn of the ECU (which your independent shop probably wont be able to do.)

 

Here is the TSB on that code:

 

 

 

 

Classification: Reference: Date:

EC00-011 NTB00-041 May 2, 2000

2000 MAXIMA & SENTRA, 2001 PATHFINDER;

DTC P0505 DUE TO INCORRECT ENGINE IDLE SPEED

APPLIED VEHICLE(S): 2000 Maxima (A33)

2000 Sentra (B15)

2001 Pathfinder (R50)

SERVICE INFORMATION

If one of the Applied Vehicles above has a Diagnostic Trouble Code (DTC) P0505 AAC/V

stored, with no customer driveability incident, it may be caused by an elevated or incorrect

engine idle speed setting. In some of these cases, the Idle Air Volume Learning (IAVL)

procedure should be performed to resolve the incident.

Use the Service Procedure outlined below to identify and address this incident.

NOTE: The Idle Air Volume Learning (IAVL) procedure referenced here is a new

procedure for the Applied Vehicles. Idle speed is now completely controlled by the Applied

Vehicle's ECM. The "base idle speed" adjustment is replaced by the IAVL procedure.

SERVICE PROCEDURE

NOTE: If a DTC is found when checking the "SELF-DIAG RESULTS", "FREEZE

FRAME DATA" MUST be printed BEFORE the code is erased.

1. Using CONSULT-II, select "ENGINE" and "SELF-DIAG RESULTS." Verify that DTC

P0505 AAC/V is stored. Select "PRINT" and attach the printout to the work order for

future reference.

2. Select "F.F. DATA", select "PRINT" and attach the printout to the work order for future

reference.

3. Does the Freeze Frame Data printed in step 2 show an engine temperature above 158°

F (70° C) and an idle speed near the target idle speed show in the chart below?

MODEL IDLE SPEED

2000 Maxima M/T: 625±50 rpm, A/T: 700±50 rpm (in "P" or "N" position)

2001 Pathfinder 750±50 rpm (A/T in "P" or "N" position)

2000 Sentra (SR) 800±50 rpm (A/T in "P" or "N" position)

2000 Sentra (QG) M/T: 650±50 rpm, A/T: 800±50 rpm (in "P" or "N" position)

• If yes, proceed to step 4.

• If not, refer to the EC section of the applicable Service Manual for diagnosis of DTC

P0505, including circuit checks.

2/3

4. Start the engine, bring it to operating temperature, and then let it idle.

5. Press "BACK" on CONSULT II to back out of "F.F. DATA" and "SELF-DIAG RESULTS."

NOTE: "BACK" may need to be selected more than once to get to the desired screen.

6. Select "DATA MONITOR" and "SELECTIONS FROM MENU". Select the following

items:

• Engine Speed.

• IACV-AAC/V.

• Ignition Timing.

• COOLAN TEMP/S.

7. Press "START" to launch "DATA MONITOR". Then press "COPY" to print the items

selected and attach the printout to the work order for future reference.

8. Press "BACK" on CONSULT II to back out of "DATA MONITOR", then select "WORK

SUPPORT" and "IDLE AIR VOL LEARN."

NOTE: "BACK" may need to be selected more than once to get to the desired screen.

9. Press "START" and wait for the procedure to complete (usually 20 seconds to one

minute).

NOTE: For detailed instructions on this procedure, or if the display shows "INCMP" or if

the procedure does not complete after one minute click here or refer to Attachment "A"

to the print copy of this bulletin.

10.After the "IDLE AIR VOL LEARN" status shows "CMPLT", Press "BACK" on CONSULT

II to back out of " IDLE AIR VOL LEARN."

11. Select "DATA MONITOR" and "SELECTIONS FROM MENU". Select the following

items:

• Engine Speed.

• IACV-AAC/V.

• Ignition Timing.

• COOLAN TEMP/S.

12.Compare the current "DATA MONITOR" information with the results printed in step 7,

above.

• The target idle speed and ignition timing should be within the specifications shown in

the chart below.

• The AAC/V steps should reflect a change from the prior reading. If either condition is

not met, click here or refer to Attachment "A" to the print copy of this bulletin.

MODEL IDLE SPEED IGN TIMING

2000 Maxima M/T: 625±50 rpm, A/T: 700±50 rpm (in "P" or "N" position) 15°±2° BTDC

2001 Pathfinder 750±50 rpm (A/T in "P" or "N" position) 15°±2° BTDC

2000 Sentra (SR) 800±50 rpm (A/T in "P" or "N" position) 15°±2° BTDC

2000 Sentra (QG) M/T: 650±50 rpm, A/T: 800±50 rpm (in "P" or "N" position) 9°±2° BTDC

13.With the engine at operating temperature, test drive the vehicle to verify the DTC does

not reset and the idle speed remains stable.

3/3

CLAIMS INFORMATION

Submit a Primary Failed Part (PP) line using the following claims coding:

OPERATION PFP OP CODE SYM DIA FRT

Perform Idle Air Volume

Learning procedure

* DE96AA AF 41 0.3 hrs

Diagnosis - DTC P0505 -

IACV-AAC Valve

EE33AA 0.4 hrs (A33)

0.5 hrs (B15/QG)

0.4 hrs (B15/SR)

0.5 hrs (R50/VQ)

* Reference the appropriate Parts Catalog and use the indicated IAVC-AAC Valve Part

Number as the PFP.

[zpmada]

I dont understand how they got off on testing the ECU and replacing it and all with a P0505 code, it is just a simple relearn of the ECU (which your independent shop probably wont be able to do.)

 

Here is the TSB on that code:.......

 

 

Sorry I should have been more specific. When I took it to Nissan the first time, they did "re-learn" the idle speed. The Check engine light was off. However, the next time I started the car the check engine light came on and P0505 returned.

[Alkorahil]

Why didnt they replace the IACV then? Not unheard of to do on the 3.5L when it is 10 years old.