1998 Dodge Ram Dodge Ram 1500 code P1392

Tiny
TOFAST4US10
  • MEMBER
  • 1998 DODGE RAM
  • V8
  • 2WD
  • AUTOMATIC
  • 198,000 MILES
I have a truck that I purchased and it was throwing code P1391, Intermediate Crankshaft or Camshaft Position Sensor Failure.
Here is what has been done to the truck so far and has not worked
2 Crankshaft Position Sensors
3 Camshaft Position Sensors
1 Powertrain Control Module
New Distributor, Coil, Plugs, Wires, Cap & Rotor
1 New Distributor

The truck has been to a small time mechanic and a five star Dodge dealer both of which could not diagnosis it.

It also has another problem the speedometer dosen't start to work until 30 mph and the brake light is on. It has new pads and shoes and brake fluid so I know that isn't the case. The Dodge dealership said that they could fix this with a new speed sensor so they put one in (and charged me for it) but it didn't work and after that they said it couldn't be diagnosed either.

Any help would be greatly appriciated, if your answer is correct I will gladly donate money to you but I've already paid over $500 and had a lot of work done (and done a lot myself) for incorrect answers.
Monday, July 26th, 2010 AT 11:55 AM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Hi:
It sounds like you have been working on this. Honestly, I can't tell you a specific part to replace. However, based on what you are going through, I can add my 2 cents. I have been working on cars for 30 years, so I'll do my best to help.

Based on everything you have mentioned, I feel you are dealing with a couple different problems. The concern is the code, PO1391. If you have replaced them several times only to come back with the same problem, they are not the cause. I need you to check wiring for continunity from the sensor to the PCM. The code you are getting is telling me that they work and then they don't. My guess ( at this point) is you have either corrosion as an issue or the wiring internaly is partially broken. When you check, move the wire around to see if there is any change or evidence of a break in the wire that would either cause a loss of continunity or an increase of resistance. Also, check the plug on the PCM to make sure nothing is bent, pushed loose, or corroded. I don't believe there are any splices in the wiring from the sensors, but that would be another thing to check for. Many times I have taken apart wiring harness to find a "Factory Splict" that has corroded and caused the problem.

Check and let me know what you find.

Joe
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Monday, July 26th, 2010 AT 11:01 PM
Tiny
TOFAST4US10
  • MEMBER
  • 2 POSTS
The wiring was what I was thinking of next also, I should have a chance to work on the truck again on Friday (I work 4 -12 hour days) so I'll check that and let you know.
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Tuesday, July 27th, 2010 AT 5:26 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
It may be frustrating, but when checking for continunity, move the wires around to see if there could be a break in one of the wires.

Let me know what you find.

Joe
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Tuesday, July 27th, 2010 AT 9:03 PM

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