2002 Dodge Ram 4.7 Faulty Crank Sensor

Dodge Crank Sensor Issue

Engine stall out at stop signs and red lights

United States 2002 Dodge Ram

Dodge PCM and Wiring Issue
Engine speed circuit malfunction
Speed input circuit malfunction
OBD Code P0320 & OBD Code P0725 On Dodge Ram
O2 Sensor issue on Dodge

Q: 2002 Dodge Ram 4.7, wires near the exhaust got hot and melted and set off the P0320 Code (engine speed circuit malfunction) and P0725 (Speed input circuit malfunction).Fixed the wires and problem solved. Last week this started again with the same codes. Now the wires look fine and the engine likes to stall out at stop signs and red lights. Then it wont start unless I unhook the battery for a minute and then it will start right up. All three O2 sensors error codes came up which is almost impossible that they all go bad at once. When unhook the battery it resets the PCM however; the light does not go off. Would I need a new crank speed sensor ? The wires go to a sensor in the side of the transmission. Could that sensor be bad?


A: There are few possibilities to be checked and confirmed.

Replace Crank Sensor

OBD codes P0320 and P0725 is coming up and the wiring for the exhaust is ok then almost surely you have a bad crank sensor. It's not uncommon for the crank sensor to fail this way and produce an intermittent signal, causing these codes and symptoms.
Crankshaft sensor it is located on the lower part of the engine just behind the harmonic balancer

Dodge Crank Sensor:

Oxygen Sensor

It is unlikely that multiple oxygen sensors would fail at exactly the same time. If the codes started to set at exactly the same time as the crank sensor issue then I would recommend repairing that first and see if maybe the oxygen sensor codes don't come back. It's unlikely that the problem is related but possible. It's possible that you have a wiring, sensor, or PCM problem, but it's unlikely that all three sensors would fail at the same time, if in fact all three codes had set at the same time.

Start with repairing the crank sensor issue, clear the codes and see what comes back before going much further with the oxygen sensor problem.


Transmission Sensor

The sensor on the right rear of the transmission is the line pressure sensor, it's not related to this issue.


Wire schematic of the crank sensor circuit

There are 3 wires.

1. The signal wire is gray/black, it goes from pin 1 of the sensor connector to pin 8 of PCM connector 1. PCM connector 1 is the solid black connector.
2. The sensor ground is the black/light blue wire in pin 2 of the sensor and it goes to PCM connector 1, pin 4.
3. The 5v supply wire is orange and runs from pin 3 at the sensor to PCM connector 1 pin 17.

Please Note: The crank sensor doesn't connect to the transmission speed sensors, the speed sensors are dedicated two wire circuits to the transmission control module.

This will help.

Thanks.

Dodge RAM 1500 Starting Problem

Warning Lights On Dodge Ram

Dodge Starting Issues

Multiple Warning Light indicators on Dashboard

Q: 2009 Ram 1500 4 door 2WD with the 4.7 engine. When it starts 5 of the dash board warning lights stay on. The Brake warning, ABS warning, ESP, ESP, and BAS Light. Two days after this it won't start.

Auto zone checked Battery, Alternator, And Starter. All good.


A: As per what the problem is described.

Dashboard warning Lights

The warning lights are likely going to be unrelated to the starting problem. These lights have come on because the ABS module has seen a failure somewhere in the system and set a fault code, the first thing that will need to be done to diagnose this is use a capable scan tool to see what fault codes have set.


Common Possibilities For warning light On Dash board

It could be anything from a wheel speed sensor to the ABS module itself, steering angle sensor, brake pressure sensor, wiring between the components, etc.


Dodge starting problem:

The starting problem sounds like it's a connection issue. If the battery was truly dead then you would have to jump start it, if all of a sudden battery voltage appears and you can start it that tells us there is a connection/voltage drop issue.

Things To try:

• The first thing to try is voltage drop test the positive and negative cables when this happens. 

• It can be poor connection right at the battery, inside the cable where the terminals crimp to it, a ground issue or a connection issue at the TIPM (fuse box/module under the hood). 

• It's also possible that the TIPM itself could be the issue.

This details will help.

Thanks.

Cruise Control Stop Working?

2001 Durango Cruise Control Light Stop Working

2001 Durango with the 4.7 V8 2wheel drive. What would cause the cruise control to stop working all of the sudden?

Previous Issues:
Had A/C issues with not blowing cold, pumped out the system and recharged also find the vacuum leak that has been keeping the check engine light on and fixing. The cruise light comes on when turned on but will not set.

Already Checked:
Have checked all the fuses  all are good. Any ideas?

More Suggestions Required:
Also would like opinion about A/C. Was blowing warm up front, but cooler in back( rear A/C), was recommended to vacuum system and recharge (in case had any air in it), did just that. It blows cold on both ends now while going down the road but still seems to struggle while idling or stuck in slow traffic. What else can I do check?


POSSIBLE TROUBLESHOOTING SOLUTIONS:

• There are quite a few things that will stop cruise from working. The cruise switches, brake switch, cruise servo, wiring, throttle position sensor, MAP sensor, trans related or some ABS related issues will prevent cruise from working. 
• If the cruise stopped working after some work was done under the hood then the first thing to check and confirm is the servo has vacuum, a line may be off or pinched. With the engine running remove the vacuum line from the servo and make sure it does have vacuum.

• The next thing to do from there would be checking for fault codes. Many of the possible causes will set a fault code, including some causes that may seem unrelated. If vacuum is ok and no codes are set then monitoring some data on a scan tool may be necessary to see why it isn't working.

There are several possible problems with the cruise control system. 1- loss of vacuum to the servo. The servo pulls the cable that opens the throttle . It is located under the battery tray. The servo can get battery acid on it. The acid can eat a hole in the servo or- most likely the vacuum line that feeds the servo.

There should be a strong vacuum with the engine running at the vacuum line to the servo. If no vacuum if felt- back trace the line to the reservoir located under the cowl on the passengers side.

There is a vacuum line that connects the tank with the vacuum supply from the engine,. The other problem we see often is the clock spring assembly in the steering wheel has a bad internal circuit,This part connects the switches wiring through the column to the under dash wiring harness. And the switches can become dirty and not make connections,. A scan tool is used to monitor the switch output from the steering wheel controls, Some times pushing the switches will clean them up enough to work for awhile.



The A/C Problem 
The original a/c problem sounds like a bad front expansion valve, but I wouldn't replace it unless you start having a temperature difference between front and rear again. If it cools ok when driving but warms up at stops that is a sign there is little or no airflow over the condenser because of a fan issue. Depending on build you may have just an engine driven fan, just an electric fan or both. Whichever system you have, it sounds like the fan isn't turning on or engaging while you are stopped.

Getting all this Possibilities Checked And Confirmed will Help.
Thanks.

Dodge W250 4x4 Charging System Problem

Vehicle Charging System Problem

PCM Wiring Issue On Dodge 

93 dodge w250 diesel has charging problem.Replaces the alternator and the cps sensor reads good also the relays work fine.The truck wont charge while the wait to start light is on but after awhile it goes off and it starts charging, tried cleaned all ground connections and still it dont charge sometimes it takes a hour before the charging system kicks.Is it a bad pcm?


Troubleshooting Solutions For The Problem:

Yes It Seems Like Its A Faulty PCM:

• It does sound like you have a bad PCM. What would often happen with these SMEC type PCM's is they would partially power up when the key is first turned on but they wouldn't fully come alive and operate. If you're seeing the wait to start light come on for that amount of time and the charging system doesn't work then that tells me the PCM isn't fully coming alive.

Another Possibility Can Be Faulty Crank Sensor:

• How was the crank sensor tested? Internally shorted crank sensors did cause some problems on these, they could take the PCM down. It's suggested to unplug the sensor at the time the wait to start light won't go out, make sure the light doesn't go out. If it goes out as soon as the sensor is unplugged then you know the sensor is the issue.

Inspect Electrical Connectors And Ground Wire Connections:

• I would verify the PCM powers and grounds are good at the time it acts up. The best thing to do would be use a headlamp or fog lamp bulb and a couple jumper wires and if the bulb lights brightly this will ensure the circuits are capable of supporting a load.

PCM Wiring Test Details:

• You should have battery voltage on the dark blue wire in pin 9.

• You should have battery voltage on the red wire in pin 3.

• You should have ground on the black/tan wire in pin 11 and 12.

Why It Seems PCM Is The Possibility?

The flickering of the wait to start light and ASD relays and then the charging system starts working is a sure sign that the problem is internal in the PCM. 

Try load test the powers and grounds when it is acting up to be sure, but what you are having is a common failure mode of a SMEC type PCM and replacing the PCM is going to be necessary.

Installing/ Replacing Voltage Regulator

If you didn't need or don't have an automatic trans, cruise control, speedometer or a/c then you can install an external voltage regulator and not worry about the PCM. A correctly installed and known good voltage regulator will allow it to charge, although if the PCM isn't working you wont be able to use the charging gauge/battery light in the dash to know that it is charging.

This Details Will Help.

Thanks.