'97 mini-van, 3.0l 3-speed auto.: codes 0403/0743

QuestionEdit

QUESTION: I have a 97 Dodge Caravan 3L V6,everything works great drives and rides like new instrument panel fine, a/c fine, brakes great, just had the reverse fixed in the transmission and had all new seals and the rear oil seal replaced doesn't leak anything.My Service Engine light just came on with these codes...P0743,and PO403, I got these codes from Auto Zone I have the read-outs but want to confer...PO403 detected a fault in the EGR solenoid circut.PO743...detected and open or short condition on the solenoid circut.oould these issues be one in the same? Where are these located and how much approximated. would it be to have fixed,Thank you so much for your time.

ANSWER: Hi Randal, Those codes involve different components. The 0403 is about the egr valve solenoid operational circuit which is a 2-wire connectio from the egr valve on the engine: white/black wire should show 12v from the positive temp fuse-like device #1 in the bottom row of the fuse box under the dash when the key is 'on', and gray/yellow wire is to pin 40 of the pcm. So check those for voltage on the first, continuity on the second, and check for continuity across the egr solenoid itself with the plug removed, Also check the action of the valve which has a stem hidden in the flange between the solenoid and the valve body. Put a tip of a screwdriver in the slot of the stem and move it back and forth, against spring-action which tries to close it. If it is 'sticky' then spray some WD-40 on the stem where it enters the valve body and move it some more. The 0743 is about the torque converter solenoid on the transmission and its circuit situation. If the torque converter lock-up isn't happening above 40 mph, that is why. Again, a simple two-wire connection on the trans at a plug near the forward end of the trans. It also is powered out of the same positive temp coefficient device #1! I suspect that device may be faulty so verify that it shows continuity across it pins, and is carrying 12v when the key is on. The white black wire at the solenoid should show the same 12v as above. And the other wire is orange black to pin 56 of the pcm. But chances are the PTC #1 needs to be replaced (it is 9 amp size). Or of course it could be alright and there are two separate issues with the wiring or the devices in question. Please 'rate' my answer (see below). Thanks, Roland

Roland

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QUESTION: is it ok to drive this way or could this lead to a more serious problem and apprx how much is the cost to fix? 9amp fuse in the fuse box under dash?

AnswerEdit

No problem with driving it. If it is the PTC it is I believe a simple unplug/plug, but it may be a bit more that that...I am not certain. But EITHER take a look under the dash at the very bottom row, far left socket. OR check whether the white/black wire at either the egr or the trans torque converter clutch plug shows 12v or not with the key 'on' which would show you if the PTC is blown or not. The egr is mounted in a pipe that runs across the front top of the engine, that small pipe branches of the exhaust manifold on the side of the engine facing the front or the van. Find the plug for the egr and test the pin with the white/black wire for voltage or not. Either way will give you the answer. The other plug on the trans side is the furthest forward just above the mid-line, and you can check the same 12v output from the PTC on the white/black wire there. Please rate... Roland