OK, last week the alternator clutch went out on my 03 grand caravan. I replaced the clutch pully with a regular pully off of an 01 caravan. While the alternator wasnt working I had to charge the battary and then jump it off several times to get it home. After I fixed the alternator the speedometer started jumping between 5 and 20 mph. Once I start rolling it works like normal but every time I stop it starts bouncing and sometimes the van will lunge forward several times. It seems to be shifting into 1st real hard when I put it in drive. It shifts great and runs fine but the other day when I went to leave the house I put it in gear it didnt do anything. I shifted back and forth and it finally went into gear then I drove 20 foot and it did it again. It finally went into gear and it hasnt done that again but im very concerned that im doing damage to the transmission. I have had the van for about 4 months and its always made a weird noise when u shift it into gear. Kinda like a squeeky wheel but only when its in drive. Sometimes its worse than others. Its always has a small fluid leak and it seems to do it more when its full or slightly over full. Its always shifted smooth and ran great so I just ignored it. Whatever the problem is it had to be caused by a lack of voltage when the alternator wasnt working. Any help with a diagnosis would help me greatly. Thanks.

 

Welcome to DF
I would start with a new battery. Ck the the fluid in the transmission. If its low fill it and find out what is leaking and fix it.

 

Thanks for the help! The battary is new and the fluid level is full. The leak is very minor. I drove from gulf shores, alabama to Virgina beach and it never ran low. Its actually never ran low since ive had it. I check it dailey and add accordingly. Whatever the problem is it started immediatly after I fixed the alternator. I have noticed that there is a weining noise when the van is runing. I think its probably the alternator because it had a pully with a clutch built in and now it has a regular pully with no clutch. I also bent one of the cooling fins when I was removing the pully. The problem i am having is only when the van is in gear (or neutral). When its in park the speedometer is resting on 0mph. As soon as I take it out of "park" the needle starts bouncing. Once I start rolling it stops bouncing and shows the actual speed. The only thing diffrent now is the regular pully instead of the clutch pully but I dont see how that could play a factor. When the alternator wasnt charging there were several times I charged the battary and drove it till it was dead in order to make it home. I dont know if the low voltage burned out a soilinoid or a sensor or something. Perhaps its the speed input sensor, clearly the output sensor is working because the speedometer is working. I really hate to buy the sensor if its not bad because I cant return a sensor. I may just pull one off of a junked grand caravan. I have to paint it this week for work, they want it white so white it shall be and I need a new door so I have to get one at the junk yard. They dont have any 03's but they do have several 01's and 02's. Im pretty sure there the same. Im not sure which sensor is which though. I just really hope the transmission is ok. This van is my job, if it quits im out of work! Any more help would be greatly appreciated.

 

DIAGNOSIS AND TESTING - SELF-DIAGNOSTICS
The instrument clusters are equipped with a self diagnostic test feature to help identify electronic problems. Prior to any test, perform the Self-Diagnostic Test. The self diagnostic system displays instrument cluster stored fault codes in the odometer display, sweeps the gauges to the calibration points, and bulb checks the warning indicators. When the key is in the ON position with the engine not running, the MIL will remain illuminated for regulatory purposes.

To activate the Self-Diagnostic program:
With the ignition switch in the OFF position, depress the TRIP ODOMETER RESET button.
Continue to hold the TRIP ODOMETER RESET button until Sof and a number (software version number (i.e. Sof 3.2) appears in the odometer window then release the button. If a fault code is present, the cluster will display it in the odometer display. When all fault codes have been displayed, the cluster will display “end” in the odometer display. Refer to the INSTRUMENT CLUSTER DTC'S table to determine what each trouble code means. INSTRUMENT CLUSTER DTC'S DTC DESCRIPTION
100.0 LOOP-BACK FAILURE
100.1 ABS COMMUNICATION FAULT
100.2 BCM COMMUNICATION FAULT
100.3 EATX COMMUNICATION FAULT
100.4 FCM COMMUNICATION FAULT
100.5 ORC COMMUNICATION FAULT
100.6 SBEC/DEC/MCM COMMUNICATION FAULT
200.0 AIRBAG LED SHORT
200.1 AIRBAG LED OPEN
200.2 ABS LED SHORT
200.3 ABS LED OPEN
200.6 EL INVERTER TIME-OUT
200.7 EATX MISMATCH
400.0 EEPROM READ/WRITE FAILURE
400.1 IMPROPER POWER DOWN DETECTED


CALIBRATION TEST
The CLUSTER CALIBRATION table contains the proper calibration points for each gauge. If the gauge pointers are not calibrated, a problem exists in the cluster. If any gauge is out of calibration, replace the cluster.

CLUSTER CALIBRATION SPEEDOMETER CALIBRATION POINT
1 0 MPH (0 KM/H)
2 20 MPH (40 KM/H)
3 60 MPH (100 KM/H)
4 100 MPH (160 KM/H)
TACHOMETER
1 0 RPM
2 1000 RPM
3 3000 RPM
4 6000 RPM
FUEL GAUGE
1 EMPTY
2 1/4 FILLED
3 1/2 FILLED
4 FULL
TEMPERATURE GAUGE
1 COLD
2 1/4
3 3/4
4 HOT


ODOMETER SEGMENT TEST
If a segment in the odometer does not illuminate normally, a problem exists in the display.

ELECTRONIC TRANSMISSION RANGE INDICATOR SEGMENT TEST
If a segment in the transmission range indicator does not illuminate normally, a problem exists in the display.

Here is a self test for the cluster. My guess,would be since the problem started with the alternator. Either alternator is bad or the regulator,which is the pcm.

 

Would that cause it to jult forward at stop signs?

 

OK, did the test and its sw version 5.0 and I got 2 codes, a 200.7 EATX mismatch, and 400.1 improper power down detected. Dont know what that means but thats what it says. The cluster did everything it was supposed too. Everything lit up and it did 9 diffrent tests and then the odometer lit up every light in it. Is there a way to reset the codes?

 

There maybe an eatx code in the tcm. Try leaving the battery disconncted for maybe 5 mins. and the recheck.

 

will do! Thanks for the help, big time!

 

Same codes are still coming up. I unhooked the negative terminal for 7 minutes and then ran the test again and got the same results. The speedometer is still bouncing around when its not in park and it still jults the van when its in drive or reverse. It also wants to stall if you dont hit the gas when you crank it and it wants to stall sometimes when you put it in drive and other times it slams it into first. The rpms fluctuate between 800 and 1300 rpms. It just acts completly diffrent now than it did before the alternator screwed up. It drives and shifts the same but when its sitting still its acting real weird. My fuel consumption has gone way up as well. Something is diffrent for sure. Thanks agian for the help.

 

Could be a problem with the cluster or front control module.Could have been cause by the alt.