QuestionQUESTION: 2001 PT Cruiser 2.4 with 120,000 miles. I was driving to work one morning and the car lost power and quit running. It would not crank back up. The code P320 came up for the Crankshaft Sensor. Replaced the sensor and the code came back up with the P1391. I checked the wires on the Camshaft sensor and they were kind of stuck together so I separated them. Then got the P340 code coming up with P320 and P 1391. We replaced the Crankshaft and Camshaft Sensor along with new spark plugs and wires. Now we just get the P1391. The car will crank but if you put it in gear it cuts off. Also when it cranks up and you push on the gas peddle the care revs up and down and the tach needles goes back and forth and it makes a backfire noise from the exhaust. Trying to find out if it might be the computer before spending the money.
Before I replaced the camshaft sensor it would drive around the block and run rough if you tried to accelerate and then cut off. It would start back up and only go a few feet. If you did not start it for awhile it would go further. Now you can’t put it in gear without it cutting off. P 1391 code is the only code coming up now. I’d appreciate the help
ANSWER: Hi Carol.
I would question the wiring from the sensors, between the plug and the powertrain control module, given that you found them stuck together. If you have a volt-ohmmeter or a continuity tester you can then check out each of the three wires on both sensors to see if they are connected well and are not shorting together. It sounds like one of the sensor signals is being compromised.
If so you and carefully inspect the wire and possibly repair it.
Both sensor plugs have a black/light blue wire that is connected to pin 43 on the lower plug of the powertrain controller which is located on the back side of the engine, near the firewall. Both sensors also have an orange wire which is connected to pin 44 and caries 8 volts when the key is "on". The signal wire for the cam sensor is tan/yellow and connected to pin 33 of the other plug, and the crank sensor signal wire is gray/black and connected to pin 32. At the sensor plugs, the black/light blue wires are on pin 2, the orange wires are on pin 1, and the signal wires are on pin 3. When checking for continuity gently shake the wiring harness. Also check for their being no continuity (infinite resistance) between any of the three wires for each sensor (measured while the plugs are all disconnected).
Roland
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QUESTION: I am in the process of checking the wires. The Cam Sensor reads 8.94 on the orange wire. Black and Blue wire .02. Tan wire 4.99. The Crank Sensor was reading 8.94 on orange. Black and Blue wire .02.Gray was 5.00 but now the gray wire is not registering anything now. I wiggled the wires and nothing changed. Now the car will not start and the code P0320 is coming back up.37sh
ANSWER: The 0320 is about no signal from the crankshaft sensor being seen at the PCM. Use the ohmmeter function of your meter to check the continuity (should be 0 ohms resistance) of the gray/black wire of its plug to pin 32 at the pcm plug,
When the crank sensor wire dropped to 0, was it possibly to 0.3?, had you rotated the engine possibly to another position? That sensor voltage should vary between 5 and 0.3 about 12 times for each full rotation of the engine which you can do by putting a wrench on the bolt of the crank pulley to turn it slowly by hand. If it is not reliably doing that, and instead reads 0v, then the sensor signal wire is intermittent. Because you have a new sensor, I would focus on the wires' continuity to be sure it is not a flakey connection that is causing this problem and if that is shown to not be the cause then check to be sure the sensor is seated fully in its mounting location. But at pin 32 it should read 5 or 0.3V, a reading of 0 says that the wire has been damaged along its pathway so visually check the harness between the sensor plug and the pcm to see if you can find where it is damaged and then try to reconnect the wire and insulate it.
Roland
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QUESTION: The gray/black wire is still reading 0. I rotated the engine and there was no change in voltage. I am not sure how to check continuity. I put the meter on ohms and had the black probe grounded to the battery and put the red probe to the gray/black wire and nothing changed. I put the probe where the middle wire is and it read 1.3 with the key off and 13.4 with the key on. That was the only change but I might not be testing it the right way
AnswerHi Carole,
Here is the correct way to test the crank sensor wires:
When you are testing the continuity of a wire with an ohmmeter you are assessing whether it is conducting current from one end to the other or is it broken and not so-doing. The ohmmeter is to be connected using its two probes as follow: one at one end of the wire, the other at the other end of the wire.
If the wire is good the reading will be 0 ohms or very close to that, if the wire is no good the reading will be infinite ohms or close to that.
So what you need to do is connect one lead to pin 2 of the disconnected plug at the crank sensor and the other lead to pin 43 of the disconnected plug at the PCM and see what the reading is and that will test the black/light blue ground wire. Similarly connect one lead to pin 3 of the disconnected plug at the sensor and the to pin 32 at the other disconnected pcm plug and see what the reading is. If these reading are 0 the wires are both good, an infinite reading means that a wire is bad.
You don't have to test the orange wire as you found it measured 8 volts at the sensor plug which proves the orange wire is good.
When doing the measurement gently flex each wire to verify that the reading doesn't change. Ideally you will find one of these wires is intermittently connected or disconnected and then it can be repaired. If both wires are good, then you will want to test the wires for the camshaft sensor in the same manner as it too had a history of having the wires stuck together.
I listed the pin connections for the camshaft wires above in an earlier answer.
Roland
