2005 Dodge Caravan 3.3 - multiple issues, please help!

Sorry

thats probably why the speedometer/odometer are not working due to the speed sensor problem.your right about cluster and pcm going same time.maybe the cluster did not need replaced and only a bad vss vehicle speed sensor an input to pcm for the cluster speedometer.does this shop know what they are doing?are they ase certified in engine diagnostics? also pcm needs vss input for shifting.shifting may be erratic.

thats probably why the speedometer/odometer are not working due to the speed sensor problem.your right about cluster and pcm going same time.maybe the cluster did not need replaced and only a bad vss vehicle speed sensor an input to pcm for the cluster speedometer.does this shop know what they are doing?are they ase certified in engine diagnostics? also pcm needs vss input for shifting.shifting may be erratic.

Thanks for your input. I actually did not want them to replace the cluster yet. I will probably have it replaced later on. But are you saying my current problem (cluster) has nothing to do with the replacement of the PCM?

Also, I am sorry - what are you suggesting about trans shifting problem?

Also, the place that did this work is Meineke so I hope that they know what they are doing.

there are 2 speed sensors.an input and an output speed sensor.
The Input Speed Sensor provides information on how fast the input shaft is rotating. As the teeth of the input clutch hub pass by the sensor coil, an AC voltage is generated and sent to the PCM/TCM. The PCM/TCM interprets this information as input shaft rpm.

The PCM/TCM compares the input speed signal with output speed signal to determine the following:




Transmission gear ratio
Speed ratio error detection
CVI calculation
The PCM/TCM also compares the input speed signal and the engine speed signal to determine the following:



Torque converter clutch slippage
Torque converter element speed ratio

The Output Speed Sensor provides information on how fast the output shaft is rotating. As the rear planetary carrier park pawl lugs pass by the sensor coil, an AC voltage is generated and sent to the PCM/TCM. The PCM/TCM interprets this information as output shaft rpm.

The PCM/TCM compares the input and output speed signals to determine the following:




Transmission gear ratio
Speed ratio error detection
CVI calculation
Vehicle Speed Signal

The vehicle speed signal is taken from the Output Speed Sensor. The PCM converts this signal into a pulse per mile and sends the vehicle speed message across the communication bus to the BCM. The BCM sends this signal to the Instrument Cluster to display vehicle speed to the driver. The vehicle speed signal pulse is roughly 8000 pulses per mile.

they are both magnetic sensors and produce a ac sine wave waveform on labscope.looking at scan data pids while test drive would confirm if no input to pcm then would have to test the vss circuit to see if problem is the sensor itself or the wiring/circuit/connector.
mineke may do exhaust good but dont know about diagnostics.I would talk to manager and say didnt have this problem before and cluster was probably good and the vss input to pcm/tcm was bad causing no speedometer/odometer cluster reading.they should make good at no cost to you.if not i would not go there again.

Hi autojoe, thanks for your comments and help.

To be honest with you, what you have posted is probably very valuable info. but is way too technical for me.

Bottom line, are you saying that if the speed sensor (P0501) is replaced that will take care of the transmission problem. Is cluster needs to be changed or the speed sensor?

I want to back to them and tell them to fix or i am not coming back but I want to do this with full confidence before burning bridges.

Sounds like the pinon factor was not set.

i heard of that after replacing the tcm?

the vss and circuit would have to be tested.seems funny you didnt have any problems except a no start before they worked on vehicle.did they say why pcm was at fault?no spark?the vss costs around 20-30 dollars at autozone.not hard to put in if you wanted to take a chance.hopefully they reflashed the new pcm with a programmer.I did not see a tsb for that.I would just explain to them the code and the erratic shifts and no spedometer/odometer since they replaced the pcm and what are they going to do about it.tell them that no vss input to pcm would cause no spedometer/odometer at the cluster and why would you have this problem after they replaced the pcm.

It has an NGC controller. In other words the tcm and pcm are one and the same.

jpb just checked and there is a separate TCM is located behind the left fender.but i think even if the pcm was replaced the pinion factor needs set.that maybe the problem.just need a scan tool.

All Chrysler corp minivans came with the NGC starting with the 2004 models. It is still commonly refereed to as the PCM though in reality it is a combination PCM/TCM as stated. On an 05 it's located forward in the driver's side wheel well behind the splash shield. Scroll down for diagram here:http://www.justanswer.com/dodge/4ozev-dodge-caravan-sport-2005-caravan-3-3-trouble.html

your right rip....by bad.i thing they even are on 2nd generation controllers.dealt with shift to ground 02.


ELECTRONIC PINION FACTOR (IF APPLICABLE)

NOTE: After replacing the EATX/PCM, you must reprogram pinion factor. In some vehicle applications, the pinion factor is a fixed value and cannot be changed or updated.

The transmission output speed signal supplies distance pulses to the control module (http://www.alldatadiy.com/alldatadiy/DIY~V36811939~C40309~R0~OD~N/0/108596970/110705621/110705746/110705750/34853741/34860071/56218937/97115128), which are used to calculate speed and mileage. A pinion factor is stored in the control module in order to provide the appropriate distance pulses for other vehicle systems. The pinion factor is programmed into the control module at the assembly plant.

The pinion factor must be set when replacing the control module (http://www.alldatadiy.com/alldatadiy/DIY~V36811939~C40309~R0~OD~N/0/108596970/110705621/110705746/110705750/34853741/34860071/56218937/97115128). If the pinion factor is not set or incorrectly set, any speed related functions will not operate correctly i.e. speedometer, speed control, rolling door locks, other control modules will be affected that depend on speed information.

Using the following steps, the pinion factor can be checked and/or reset using the DRBIII:


Select Transmission system, then Miscellaneous functions, then Pinion Factor. The DRBIII will display the current tire size.
If the tire size is incorrect, press the Enter key and then select the correct size.
Press the Page Back key to exit the reset procedure.
Notes About Electronic Pinion Factor Features
The nature of the electronic pinion factor requires that certain features must be taken into consideration.


If no pinion factor is stored in an installed control module (http://www.alldatadiy.com/alldatadiy/DIY~V36811939~C40309~R0~OD~N/0/108596970/110705621/110705746/110705750/34853741/34860071/56218937/97115128), the vehicle speedometer will not operate, engine speed will be limited to 2300 RPM, and catalyst damage may occur.
Selecting a wrong tire size will cause the speedometer to be inaccurate and will also cause any speed related features to operate improperly.

Update:

I finally was able to find time to take it to another auto shop for a 2nd opinion.

They tried 2 different clusters and none of them worked. They also ran a complete diagnostics and there is an EVAP code (which I was aware of and is old) and the other one is P0501 - speed sensor.

They had also replaced the speed sensor but the cluster (speedometer and odometer) still do not work.

I was told that this is most likely the PCM problem that Meineke had replaced but in order for them to conclusively state that, they have to run some other troubleshooting/tests. They will then give me this in writing (if PCM was bad). I will then take it to Meineke and have them take care of it.

I have to now find time again to bring it to their shop.

Stay tuned....

why would they try 2 different clusters?parts changers?all you need is a good scan tool/labscope/multimeter/wiring diagram and know what you are doing.......like jpb53 stated and I posted in above post......Sounds like the pinon factor was not set.....If no pinion factor is stored in an installed control module, the vehicle speedometer will not operate.

Hate to add to your misery but you should know that PCMs can be had for as little as $150 from multiple on-line sources and $250 from many parts stores. They come reprogrammed and ready to install. Takes 20 minutes to install. Many buy instrument clusters off Ebay for around $100. Stop letting these shops rip you off.