PCM for 98 T&C

[JJFURAY]

Does anyone out there know of a sure-shot method of testing the PCM on the left fender well inside engine compartment? I believe mine is bad. I've tested continuity on all wiring, no fuel pressure at fuel rail test port, not spark to ignition coil, no crank/start etc. I've had the starter and the battery tested at local parts store and they are both testing OK. I'm suspecting the PCM is not putting out a signal to the associated starting system components. The only thing I suspect, is from my stupid move of putting my battery charger on the battery BACKWARDS!! The amazing thing.... the van drove for 2 weeks before I was stranded. The engine quit while driving and I was unable to restart at all- needed a tow home. Any ideas?

[RIP]

You'll need a big bucks scan tool to test the PCM. That would be a DRBIII or a high end Snap-on.

It's not cranking? PCM may not be supplying a ground to the starter relay coil. Could be the PCM, the park/neutral circuit out of the transmission or the VTSS security system. Supply your own ground and see if it cranks.

It's cranking but not starting? Faulty or missing crank or camshaft sensor signal will tell the PCM to remove the ground to the ASD relay. That cuts power to the ignition coil, fuel injectors, fuel pump, and O2 sensor heaters.

If you've rung out the wiring in all those circuits and all is well, it may be time to bite the bullet and look for a PCM. BTW - An easy starter test? Pull the starter relay and jumper pins #30 and #87 at the relay socket. Starter should spin immediately, keys in your pocket.

The PCM is on the driver's side fender wall.

[JJFURAY]

Hey RIP,

I did exactly as you told me to test starter thru the relay using a remote starter switch from battery positive to Pin #87 and sure enough the starter cranks. Then- I applied the same 12v from the battery thru Pin #87 on the Fuel Pump relay and VOILA! The pump came alive as well, with 47 PSI of pressure at the fuel rail with my test guage. Now... I'm still thinking it's the PCM. I believe its been damaged by one of two things. First, about 2 weeks ago, we had and extremely cold night here in Central Ohio and I tried to charge the battery, but neglected to hook up the polarity correctly from the charger and I got some major sparks. However, the van had good starting and driveability for two weeks plus. Then, something else happened. The upper radiator hose blew a huge gash and anti-freeze was all over top of engine. I'm wondering of one of these events or both had contributed to my PCM going bad. On another note, what does code 940 on my odometer test mean when I hold those 2 buttons in while turning key on? My Haynes manual does not talk about this code anywhere and 999 also displayed (normal I assume). Van has 226,000 miles. Jeff

[JJFURAY]

Forgot to ask... where exactly are the cam and crankshaft sensors locate for this vehicle?

Jeff

[JJFURAY]

RIP- Last question for the evening.

I've checked and cleaned all sensors on the transaxle related to PRNDL/back-up light connectors.

After careful review of my Haynes manual and finding the position sensors on the bell-housing (for crank) and engine block (for cam) it appears that I have no way of testing those sensors without an OBDII scan tool. I have just a small pocket Actron Scanner from Auto Zone that reads MIL items and basic codes on the connector under driver's kick panel. I was not getting any cam/crank sensor codes before this mess happened, which still leads me to believe that the PCM is in fact, SHOT. Your thoughts. JJFURAY.

[JJFURAY]

replaced with new PCM. Problem solved!