The Check Engine light is on in my 97 5.2 dakota, so I got an ECU readout at the advanced auto parts and I don't know what the errors mean.

1) ignition destination* engine speed input malfunction (* i think she said destination but I may be wrong)

2) Multiple cylinder misfire

3) Cylinder 4 misfire

Does anyone know the reason that these things are happening, and how can I fix the problem?
I should also say that the truck won't start when its wet, so I'm gonna cover the exhaust and intake whenever it's gonna rain to see if that helps.

 

The rule, at least when I was still turning wrenches, was fix the first error code first, clear 'puter. If light came on again, read the code (s) and fix the first one. Sometimes when the first code is remedied, the rest go away.

 

The engine speed malfunction might mean the vehicle speed sensor is bad. It is mounted into the side of the transmission. My service manual shows it for an automatic but my manual is for a 2001 Dakota, the 99 could be similar. My truck is a 5 speed manual, and I don't know much about any of the automatics. You might check the Haynes book or look online for a 1999 Dakota speed sensor and see what you find out.

The misfire codes could be from a bad plug, bad plug wire, a bad fuel injector or a bad wire harness at the misfiring cylinder. You could do a compression check and check out the injector, pull the spark plug and see what it looks like.

Not starting when it is wet could be a cracked distributor cap. Check the rubber weather strip under the hood for leaky spots. Check the distributor cap and the rotor itself and replace if it's cracked or got corroded contacts. Replace the plug wires if they are old. Not starting when wet could be a sign you have a bad crankshaft position sensor. They have a rubber grommet that over time wears out and if that sensor gets any moisture on it, the truck will not start at all.

If yo have not done it already, at 116K you are way overdue for a tune-up. Spark plugs, spark plug wires, distributor cap and rotor button need to be replaced. Clean the throttle body, remove the Idle Air Control Valve and clean it and its orifice on the back of the TB. Lube the IAC O-ring with a little clean motor oil and lube all the pivot points and linkages on the tB with spray silicone. Reinstall the TB with a new gasket.

Disconnect the negative battery cable and hold the ignition key in the start position for 30 seconds to clear the trouble codes and reset the PCM. See if the codes come back.

Jimmy

 

need to post the actual DTC codes....example, cylinder #4 misfire is a p0304 and a p0300 for multiple misfires, but as far as the speed input, there are multiple codes that could be, need the exact one. DO NOT unplug the battery...and do not reset the pcm... the codes are there for a reason... the p0304 and p0300 could all be the plugs and wires and cap, but the speed code could be very involved... could be a vacuum solenoid, servo defective, vent solenoid, brake switch, or even a defective PCM...need to post the DTC code...

 

I didn't get the exact engine codes but I think it is way overdue for a tune up so Im gonna go ahead and do that and see if it makes a difference,
thanks

 

After you do the tune-up, disconnect the battery and reset the PCM to clear the codes and see if the CEL comes back on. There is a topic at the top of the 2nd Gen page here where you can check diagnostic trouble codes to see what they mean.

Jimmy