Help, 03 5.7L hemi Lost idle

[MrFixIt]

Use only mopar brand sensors. your code says it is the 02 sensor pre cat bank 2 ,change it and inspect the wires .

Done, and I noted a pinched wire at the passenger side pre-cat sensor. I repaired the main wire harness as the pinch was not on the sensor side of the connector.
Could this cause the module to fail if the wire was shorted to the transmission block? if so, where do I check that?
It still has the P0032 error code after clearing and repairing.

 

[Recoil]

Yes, if the wire was shorted it would cause the module to fail, but I really don't think that is the cause of the idling issue. You said you replaced the throttle body - did you also replace the throttle position sensor?

 

[MrFixIt]

Yes, if the wire was shorted it would cause the module to fail, but I really don't think that is the cause of the idling issue. You said you replaced the throttle body - did you also replace the throttle position sensor?

I thought that was on the side of the TB. So, if it is a separate part from the TB, I’ll need to get on that. Thanks.

 

[Recoil]

Yep, it is on the side of the throttle body. Did a new one come with the new throttle body or did you use your old one? Also, what about the map sensor and idle air control motor? Did you replace those (or get new ones on the new throttle body) or did you use the old ones?

 

[MrFixIt]

Yep, it is on the side of the throttle body. Did a new one come with the new throttle body or did you use your old one? Also, what about the map sensor and idle air control motor? Did you replace those (or get new ones on the new throttle body) or did you use the old ones?


View attachment 466142

I didn’t replace the MAP sensor. The TB looks like the one below. The black portion is off to the drivers side and the pictured opening faces forward to the back of the radiator. The 6 pin connection is in good shape.

 

[MrFixIt]

I didn’t replace the MAP sensor. The TB looks like the one below. The black portion is off to the drivers side and the pictured opening faces forward to the back of the radiator. The 6 pin connection is in good shape.

 

[Recoil]

Yeah, sorry - I grabbed a pic of the 5.9 TB, not the 5.7.

Have you tried to recalibrate the TPS?

 

[MrFixIt]

Yeah, sorry - I grabbed a pic of the 5.9 TB, not the 5.7.

Have you tried to recalibrate the TPS?

I haven’t. I heard it was to hold the rpm at 2500 for a min. But there must be something I missed as that was not effective. Any ideas?

 

[Recoil]

1. Insert key into the ignition and turn the key to the "on" (not start) position.
2. Wait for all of the warning lights to go out. The check engine light may remain on.
3. Slowly depress the accelerator pedal all the way to the floor.
4. Slowly release the accelerator pedal until it's all the way back up.
5. Turn the ignition key to "off".
6. Start the engine.

 

[MrFixIt]

1. Insert key into the ignition and turn the key to the "on" (not start) position.
2. Wait for all of the warning lights to go out. The check engine light may remain on.
3. Slowly depress the accelerator pedal all the way to the floor.
4. Slowly release the accelerator pedal until it's all the way back up.
5. Turn the ignition key to "off".
6. Start the engine.

Wow. That simple. I must have missed that in the manual too. Thanks.

 

[Recoil]

No problem! Keep us updated on the status.

 

[MrFixIt]

I called to have my wife do what you described. That seems to have fixed the idle. Just a calibration of the location. Thanks so much. She said it idled at 550 and increased slightly with the AC on, and engaged both reverse then drive and it was running fine.

 

[Recoil]

Very cool!

 

[MrFixIt]

Update. new thought to attack this one.
- The idle has improved to the point I can drive the truck. it stalls randomly when the gas pedal is all the way up. I can keep it running by two-footing it. Got fresh gas in it and have 60 miles now at ~8.2mpg per the headboard display.
- so the new thought... How does the pedal talk to the throttle body since there is no cable? Found the part name accelerator pedal position sensor (APPS) 'maybe'??? it is possible the gas pedal has an electronic wiper that has aged and needs to be replaced? If so, what would an APPS part be? Having trouble finding it, maybe Dodge dealer will have it.

 

[Recoil]

This is what I found in the parts manual:



That was the only reference to APPS or to the accelerator pedal position sensor.

 

[Recoil]

Here's some more info:

DESCRIPTION

The Accelerator Pedal Position Sensor (APPS) assembly is located under the vehicle battery tray. A cable connects the assembly to the accelerator pedal. A plastic cover with a movable door is used to cover the assembly. The APPS is used only with the 5.7L V-8 engine.


OPERATION

The Accelerator Pedal Position Sensor (APPS) is a linear potentiometer. It provides the Powertrain Control Module (PCM) with a DC voltage signal proportional to the angle, or position of the accelerator pedal. The APPS signal is translated (along with other sensors) to place the throttle plate (within the throttle body) to a pre-determined position. A mechanical cable is used between the accelerator pedal and the APPS assembly. Although a cable is used between the pedal and APPS, a mechanical cable is not used at the throttle body. Throttle plate position is electrically determined.


REMOVAL

The APPS is serviced (replaced) as one assembly including the sensor, plastic housing and cable. The APPS assembly is located under the vehicle battery tray. Access to APPS is gained from over top of left / front tire.
(1) Disconnect negative battery cable at battery.
(2) Disconnect APPS cable at accelerator pedal.
(3) Remove wheel house liner at left / front wheel.
(4) Gain access to APPS electrical connector by opening swing-down door. Disconnect electrical connector.
(5) Remove 3 mounting bolts.
(6) Remove APPS assembly from battery tray.
(7) If cable is to be separated at APPS, unsnap cable clip from ball socket. Release cable from plastic housing by pressing on small cable release tab


INSTALLATION

(1) Install Accelerator Pedal Position Sensor (APPS) cable to accelerator pedal. Refer to Accelerator Pedal Removal / Installation.
(2) Connect electrical connector to APPS.
(3) If necessary, connect cable to APPS lever ball socket (snaps on).
(4) Snap APPS cable cover closed.
(5) Position APPS assembly to bottom of battery tray and install 3 bolts. Refer to Torque Specifications.
(6) Install wheelhouse liner. Refer to Body.
(7) Perform the following procedure:
(a) Connect negative battery cable to battery.
(b) Turn ignition switch ON, but do not crank engine.
(c) Leave ignition switch ON for a minimum of 10 seconds. This will allow PCM to learn electrical parameters.
(8) If the previous step is not performed, a Diagnostic Trouble Code (DTC) will be set.
(9) If necessary, use DRB III Scan Tool to erase any Diagnostic Trouble Codes (DTC’s) from PCM.

 

[MrFixIt]

Here's some more info:

DESCRIPTION

The Accelerator Pedal Position Sensor (APPS) assembly is located under the vehicle battery tray. A cable connects the assembly to the accelerator pedal. A plastic cover with a movable door is used to cover the assembly. The APPS is used only with the 5.7L V-8 engine.


OPERATION

The Accelerator Pedal Position Sensor (APPS) is a linear potentiometer. It provides the Powertrain Control Module (PCM) with a DC voltage signal proportional to the angle, or position of the accelerator pedal. The APPS signal is translated (along with other sensors) to place the throttle plate (within the throttle body) to a pre-determined position. A mechanical cable is used between the accelerator pedal and the APPS assembly. Although a cable is used between the pedal and APPS, a mechanical cable is not used at the throttle body. Throttle plate position is electrically determined.


REMOVAL

The APPS is serviced (replaced) as one assembly including the sensor, plastic housing and cable. The APPS assembly is located under the vehicle battery tray. Access to APPS is gained from over top of left / front tire.
(1) Disconnect negative battery cable at battery.
(2) Disconnect APPS cable at accelerator pedal.
(3) Remove wheel house liner at left / front wheel.
(4) Gain access to APPS electrical connector by opening swing-down door. Disconnect electrical connector.
(5) Remove 3 mounting bolts.
(6) Remove APPS assembly from battery tray.
(7) If cable is to be separated at APPS, unsnap cable clip from ball socket. Release cable from plastic housing by pressing on small cable release tab


INSTALLATION

(1) Install Accelerator Pedal Position Sensor (APPS) cable to accelerator pedal. Refer to Accelerator Pedal Removal / Installation.
(2) Connect electrical connector to APPS.
(3) If necessary, connect cable to APPS lever ball socket (snaps on).
(4) Snap APPS cable cover closed.
(5) Position APPS assembly to bottom of battery tray and install 3 bolts. Refer to Torque Specifications.
(6) Install wheelhouse liner. Refer to Body.
(7) Perform the following procedure:
(a) Connect negative battery cable to battery.
(b) Turn ignition switch ON, but do not crank engine.
(c) Leave ignition switch ON for a minimum of 10 seconds. This will allow PCM to learn electrical parameters.
(8) If the previous step is not performed, a Diagnostic Trouble Code (DTC) will be set.
(9) If necessary, use DRB III Scan Tool to erase any Diagnostic Trouble Codes (DTC’s) from PCM.

Thanks so much. This is very handy since this is the first time I’ve encountered an APPS. Mopar guys are fantastic! I’m not really particular what rig I drive, so long as I can fix it.

 

[MrFixIt]

Update: The part 53032455AD is obsolete. I’m searching through my local u-pull it but having no luck.
Is is possible to adapt another pedal to to the PCM sensor input? I don’t know the resistive range of the original sensor (mine is already failed) and surely someone else has overcome this APPS problem. I was looking at the diesel and the 2005 pedals as possible work arounds since the part is discontinued and I can’t locate one.
Anyone fix their 2003-2004 5.7L gas pedal and have suggestions?

 

[MrFixIt]

Another update to the lost idle. I was doing a break job and shocks and noticed the vacuum tubes along the drivers side of the engine that connect to the solenoid under the battery had kinked/twisted. I'm sure I did that when I was rebuilding the motor and putting it back in. anyway it was likely a vacuum leak. This seemed to help my shifting issue more than the idle issue. Now, when the APPS arrives I'll put that in and hopefully get more than 8 mpg. Think I need to recalibrate the APPS after installation. Will post again in a week or so when this is changed out.