[AT] Off Topic. Need help with Dodge caravan computer maybe?

[Steve W.]

Cecil Bearden wrote:
> I know a lot of you guys have more experience with the computer systems 
> than I have.  I have suffered through Youtube videos of nearly every 
> self described ëxpert"in diagnosing a no start condition.  Here's the 
> timeline of what has been replaced and what happened.  Wife's 2003 Grand 
> Caravan w/ 3.8L V6 130000 miles.  Sat Morning, alternator making loud 
> whine heard 40 yds away.  Alternator would burn your fingers after 
> running only 4 minutes.  Dropped Alternator and found noisy water pump 
> also leaking when inspecting other pulleys.  Replaced alternator and 
> water pump after bolt broke off on water pump.  Drilled it out Sat night 
> with cordless screwdriver and hex chuck style bits.  Had partial threads 
> so used a longer bolt and put a nut on back side.   Got it back together 
> on Sunday and had to wait until Mon morning to get some Christmas tree 
> fasteners to hold the belt shield.  Tuesday my wife drove it nearly 150 
> miles in OKC and made at least 15 stops running errands with no 
> problems.  Arrived at front gate and engine died.  Would not start when 
> cranking.  It is possible she stopped and backed up when it died, ( just 
> info for later )  but I cannot confirm.  Found battery ground cable 
> loose after engine would not crank.  Tightened cable and cranked 
> engine.  After several tries the starter would just spin and not engage 
> the flywheel.   Wednesday got reman starter and spent 3 hours removing 
> the old one.  I installed the new starter this morning, and it would 
> crank but not start.  The new starter really grinds, sounds like it is 
> coming apart.  Removed spark plug and cranked with spark plug 
> grounded.   No spark.  Changed ignition coil and still no spark.
> 
> I don't know where or how to start looking.  Since the battery cable was 
> loose and I took off the ground to install the starter, the codes are 
> not in the computer.  I don't find any method for testing the ECM.  
> There are some forum discussions on the flex plate cracking around  the 
> crankshaft in an octagon pattern and the flex plate shifting.  When this 
> happens, the crank position sensor works on the flex plate, and is then 
> out of time with the cam position sensor.   I cannot find an inspection 
> plate to look at the flex plate.  It would be a 2 day job for me to 
> remove the transmission to look at the plate.  However, I wonder about 
> the original starter just spinning and then the replacement sounding 
> like it is about to fly apart.  If the flex plate is not right, the old 
> starter might have not been able to mesh and the new one is meshing but 
> in a bind.  The old starter had to be pried out of the housing as the 
> nose of the starter was nearly pressed into the bell housing.  The new 
> one was easily pushed into the housing.   So far I have lost over 3 days 
> and nearly $500 working on this when I need to be working on the swather 
> and the water pump on the 1270 Case to pull the swather.  An ECM is 
> another $400, and replacing the flex plate will be at least $600 because 
> I need to send it out.
> Has anyone had any experience like this?   I know if I take it to the 
> stealership, I will be out $1000 by the time they get done.  I don't 
> have an independent mechanic here I can trust, and if I have to spend a 
> bundle on this car, I am about ready to buy a new one and try to get a 
> 20 year extended warranty!!!  Then maybe I can get some work done.
> 
> Cecil in OKla


Grab a voltmeter. Turn on the key and test the crank sensor for power 
and ground, It is on the bellhousing right below the crossover pipe for 
the exhaust. 3 wires, Brown/Pink is 8 volt bias voltage, Dark Blue/Dark 
Green is the ground. Brown/Light Blue is the signal wire. If you have a 
scope you would see a square wave on that line.

Easy cheat IF it has a tach, Does the tach move at all while cranking?

Next, disconnect the battery. Hold the two cables together for about 30 
seconds, this will drain the KAM capacitors. Now reconnect the cables.
Turn on the key and lock/unlock the doors twice.
See if it starts. You may need to step on the throttle if it acts like 
it wants to start because it will need to relearn the TPS output again.

csr684  at  yahoo  dot com  if you wish to continue.

-- 
Steve W.