What is po 403 - 1997 Dodge Caravan

as far as these codes they refer to the PCM signals to the o2 sensors ,but i don't think they would affect the cooling fans , does the engine overheat ? are you loosing coolant ? one reason the fans may not cut in is if the waterpump isn't working but you would have noticed lowcoolant , do the top and bottom radiator hose's get very hot ?if both hoses very hot and you've changed the sensor etc it may well be the actual fan motors , try putting a direct power and earth to the fan wire connectors , this way you will know if fans are good if they start , then the problem may be in the wiring , which can be a nightmare to trace , hope this is of some help

do you mean a 403 or have you got the year wrong ?, if a 403 follow this link and search for the timing there
Specs 1991 BMW 850i automatic

contact parts store for code analisis may have a faulty computer..

PO 403---Exhaust Gas Recirculation Circuit Malfunction

What actually is wrong,don't know

Has to be looked over & a few things tested by a repair shop

Trouble Code: P0403

EGR Control Circuit Malfunction
Possible Causes:


EGR solenoid control circuit is open or shorted to ground . EGR solenoid power circuit is open (check power from relay) . EGR solenoid is damaged or has failed . PCM has failed .

Your new EGR valve (assuming it wasn't defective out of the box), is fine, but the car's computer just needs to have its code 403 cleared. Even though you've corrected the problem, the computer will still light the "Check Engine" light, and store code 403 until the code is cleared using an OBD-II (On-Board Diagnostics 2) code scanner.
Note that the car will function perfectly with its new EGR valve, a lit "Check Engine" light and a code 403 stored. Its just a good idea to clear the code, so that then only NEW problems will become the reason that the "Check Engine" light gets lit.

code P0403 EGR ( exhaust gas recirculation ) valve solenoid malfunction, could be many things most likely would be just a bad control solenoid but could be the wiring to the solenoid, but most likely is not a bad EGR valve.

PO 171 & 174-are O2 Sensors Codes,forget them,just be sure their screwed in tight. Yes ,they will come loose.
PO303-is a bad COP Coil,on #3 cyl ,may be one issue,very common on all ford products
PO-403 -is EGR related.-That probably is shot, also.

Had all thoses and more, on my Lincoln Ls

A misfire will set many codes,that while not unrelated,are not your issuse. You need to understand the symptom,is not always what caused the codes,or not the cause of the problem.

Fig. : Cylinder head torque sequence, 260, 307, 350 403 Oldsmobile built engines




On the V8, tighten the bolts, in the sequence illustrated, to 100 ft. lbs. When all bolts have been tightened to this figure, begin the tightening sequence again, and torque all bolts to 130 ft. lbs.

On V6's, tighten all head bolts in sequence to the following torques:
* All except bolts 5, 6, 11, 12, 13 and 14 - 100 ft. lbs.(19-135.5 Nm)
* Bolts 5, 6, 11, 12, 13, and 14 - 41 ft. lbs. (19-55.5 Nm)
* All bolts except 5, 6, 11, 12, 13, and 14 - 142 ft. lbs. (19-192.5 Nm)
* Bolts 5, 6, 11, 12, 13, and 14 - 59 ft. lbs. (19-80 Nm)



Hope this help (remember comment and rated this).