Engine/Transmission (1998.5 - 2002) Transmission hunting

[Renoram]

My transmission is hunting. I have reset the APPS with no help. A couple of months ago I read an article about wraping the battery cables with aluminum foil- with photos. I can't remember if it was on the forum or in the magazine. I have searched but cannot find it again. Does anyone remember where it is? I want to try this before I buy a noise filter or reroute the pcm to apps wire.

 

[Whiskey]

My transmission is hunting. I have reset the APPS with no help. A couple of months ago I read an article about wraping the battery cables with aluminum foil- with photos. I can't remember if it was on the forum or in the magazine. I have searched but cannot find it again. Does anyone remember where it is? I want to try this before I buy a noise filter or reroute the pcm to apps wire.

Thhere is a article in the last issue of TDR mag.

Whiskey

 

[fox]

Clean all battery posts too. The foil is wrapped around the wire going from the passenger battery to behind the alternator.

The noise filter solves it.

other things are

bad batteries

Bad grounds

noisy alternator.

 

[DavidC]

Scroll to the bottom of the page

http://turbodieselregister.com/news/archive.php



Dave

 

[Renoram]

Thanks Guys for the replies. That's what I was looking for. I started with the wrapping the 10 gauge wire going past the alternator from the passenger battery negative post. So far its working great. But now I am getting a check engine light with codes of P0122 & P0123. I dont know if it is coincidental. I have a code reader & have erased them twice & it's back. Any ideas on that ?

 

[DavidC]

P0122 Throttle/Petal Position Sensor/Switch A Circuit Low Input

P0123 Throttle/Petal Position Sensor/Switch A Circuit High Input



Sounds Like a new one is due. How many miles on engine?. Did you recalibrate per DTT's instructions floating around here?.



Dave

 

[DavidC]

RESETTING THE APPS SENSOR.

(ACCELERATOR PEDAL POSITION SENSOR)

2ND GENERATION 24 VALVE TRUCKS ONLY.



LIST OF TOOLS NEEDED



DIGITAL VOLT METER

# 20 TORQUE BIT SOCKET

# 1 PHILLIPS

# 10 MM SOCKET



Proper service and repair procedures are vital to ensure personal safety of those performing the repairs. Standard safety procedures and precautions should be followed at all times to eliminate the personal injury or improper service, which could damage the vehicle or compromise its safety.

Although this material has been prepared with the intent to provide reliable information, no liability is assumed in reliance of this material.



It has come to my attention that a lot of people think by disconnecting & re-connecting the batteries and stepping on the throttle it is going to reset the apps, no, that is not correct. It is impossible to adjust your apps if you do not know where it is supposed to be set at. That is why you need the voltmeter.



This is the procedure I use to re-set the apps.



With the key on, engine off you need to probe the apps wire to see where your voltage is currently set at.

The best location to probe the wire is on the PCM (power control module) which is located off the passenger side of the firewall.



· You want the C1 connector, this is the connector closest to the engine,

· You want the orange wire with the dark blue tracer which is pin # 23

· Voltage should read somewhere around 0. 5 volts,

· At this point the voltage reading does not matter, it just has to be accurately written down for later reference.



*** TURN THE IGNITION OFF ON THE TRUCK ***









Resetting the APPS Sensor cont. page 2

(Accelerator Pedal Position Sensor)

2nd generation 24 valve trucks only.



· The apps sensor is located slightly above and a little to the left of the injection pump.



· Remove the black plastic cover that is located by your injection pump.



The two screws that are holding it are plastic, do not put any downward pressure on them or you will never get them off.



· Un do the 6 - 10 mm headed bolts that hold the bracketry in place.

(DO NOT REMOVE THE CABLES)



You will notice the apps is on the back of the bracketry that you just removed, it is held in place by 2 - 20 bit screws. These screws have a little bit of locktite on them so make sure you have a good socket and gently give a little tap with a hammer before attempting to loosen. Be very careful these screws strip very easily and you only get one shot at them.



· On the apps you will find a white tag that gives you the information on what the apps adjustment should be.



· After loosening the screws you can rotate the apps both clockwise and counter clockwise to get the adjustment you need.



· The reading you took at the beginning of the process on pin # 23 should match the white tag on your apps, if not adjust accordingly.



Dave

 

[Renoram]

Thanks for the info Dave. I have about 110k miles. I reset the APPS per the factory service manual. I changed the APPS last year but wasnt sure that was the problem previously, so I kept it just in case it was still good. About a month ago I got a check engine light (I forgot the code) for the APPS. I changed it back to the origianal one & havent had any problems up until a couple of days ago. Today I got the chk engine light again twice. It was P0123 both times. I reset them & it is still out. I suspect it will be back tomorrow. I will try & reset the APPS ASAP per your instructions. Interesting that the service manual doesnt have you do your procedure. Hope its not the APPS bad. I remember it costing around $250.

 

[DavidC]

The instructions are from Bill at DTT. Hope it cures your problem, let us know one way or the other.



Dave

 

[Renoram]

I got a chance to do the DTT procedure today. I started with . 494vdc. I took the APPS out & read the white label. It said . 609vdc. There also was a waring on the switch bracket not to adjust the switch. The instructions were easy to follow. I did not have any complications loosening the adjustment screws. It was extremely sensitive getting the voltage locked down, but I finally got it. I erased the p0123 code & cranked it up & it went to 1200 rpms idle. I drove & shut it off a couple of times & it finally dropped back to normal around 650 rpms. I drove it once on the freeway. It shifted smooth, worked great & no repeat codes. I will keep an eye on it & report later if it fails again or is fixed for good. Thanks again.

 

[DavidC]

Hope all of this solves your problems.



Dave