How to display error / fault codes 2001 Dodge Ram?

What combination of switches or knobs do I push to get a listing of any error or fault codes for a 2001 Dodge ram (5.2 L / 318 V-8 with overhead information console) ?

It cranks fine but is not starting, is displaying "no bus" in the odometer, and is showing "CCD" on the overhead display where the fuel DTE and MPG readings should be. Fuel guage reads way below empty.

It's got very low miles (about 20k) and spends most of it's time in a garage. Recently it spent a few days outside during very heavy rain.

At first I thought someone stole gas out of the tank, but it seems I'm really just having an electrical connection problem.

I want to go through the list on this page:

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But I need to get an error code first, hence my question about codes.

Thanx.

Reply to
MoPar Man
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Quick GS using ["no bus" CCD dodge] and this interesting link popped up.

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or
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. Yeah, I know, a 99 durango is not a '01 Ram, but could point you in a good direction to begin looking. Also try
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FMB

Reply to
FMB

Ok, this worked for me (2001 Dodge Ram short cab long box):

  1. Ignition switch off
  2. Press and hold the trip reset knob
  3. Turn the ignition switch to on but do not start.
  4. Hold the reset knob for approx 10 seconds or until the word CHEC appears in the display then release.

When I saw "chec" in the odo display, I let go of the trip reset knob and the following numbers appeared one after another:

900 920 921 940 950 999

I take it that 999 is like an "end-of-code" indicator.

So I'm pretty much getting this entire laundry list:

900 The CCD data bus is not operational.
  1. Check the CCD data bus connection at the cluster. 2. Check the cluster fuses. 3. Check the CCD data bus. 4. Check the CCD data bus voltage. 5. Check the CCD data bus terminations.

920 The cluster is not receiving a vehicle message from the PCM.

  1. Check the PCM software level and re-flash if required. 2. Use a DRB scan tool to verify that the vehicle speed message is being sent by the PCM.

921 The cluster is not receiving a distance pulse message from the PCM.

  1. Check the PCM software level and re-flash if required. 2. Use a DRB scan tool to verify that the distance pulse message is being sent by the PCM.

940 The cluster is not receiving an airbag message from the ACM

  1. Check the CCD data bus connections at the ACM. 2. Check the ACM fuse.

950 The cluster is not receiving an ABS lamp-on message from the CAB.

  1. Check the CCD data bus connections at the CAB 2. Check the CAB fuse.

The truck has been parked for a few days outside and has experienced several bouts of torrential rain. I haven't been able to start it since. It was running fine prior to being parked. Haven't had any problems with it like this since the day I bought it new (March

2001). It's got no leaks that I'm aware of.

When I turn on the ignition, all the guages move. Battery moves to 8 volts, temp moves to 55, oil pressure moves to 0, and even the fuel guage moves a little (but not to the zero or E mark).

I guess I'll have to poke around under/behind the dash, or maybe the engine compartment.

If anyone's got any tips, I'd love to hear them.

Reply to
MoPar Man

Not a truck technician but what you have is a total bus failure. there are a few things you can check. The C130 connector, the connector that is mounted at the firewall that feeds the inside. (Its a 43 pin connector) Since you say it happened when it was in the rain for awhile I would start there. Separate it and check for corrosion. There could be other reasons as well. A bad ground for the engine controller is possible. There are connectors below the dash at the Knee blocker that could effect this as well. Of course an engine controller could also be at fault.

Glenn Beasley Chrysler Tech

Reply to
maxpower

I've tried that procedure several times, but it doesn't seem to start a diagnostic reporting process. The only thing that happens when I perform an [on-off] [on-off] [on] ignition-key cycle is the same thing that happens when I just switch the ignition to on - which is the usual bell and light show from the instrument panel.

Voltage measured at the battery (with everything off) is 12.15 volts. When the ignition is switched on, battery voltage drops to 12.05 volts (DRL comes on too, which is normal). Why the guages (especially the fuel gauge) is reading below E, I have no idea.

Reply to
MoPar Man

Turn the key off-on-off-on-off-on. The display should then show any error codes present. It takes a few tries to get the timing of off-on right but it works.

M> What combination of switches or knobs do I push to get a listing of

Reply to
miles

Let's say the ignition switch has these settings:

1) key-insert / key removal position 2) radio only position (one step counter-clock-wise from 1) 3) unknown (off?) position (one step clock-wise from 1) 4) Ignition/run position (one step clock-wise from 3) 5) crank engine position (one step clock-wise from 4)

I assume that for the off-on off-on off-on sequence, that "on" is position 4 and "off" is position 3.

When I perform an off-on-off sequence, the bell rings immediately. When I perform an off-on (and stay on) sequence, the bell rings 6 times, then the odometer reading flashes 4 times and changes to "no buS", then the bell rings 4 times then a pause and then it rings 2 more times (and the low-fuel indicator comes on).

When I perform an off-on off-on off-on (and stay on) sequence, the bell rings (or starts to ring) between each step, and at the end it does what I describe above (rings 6 times, etc).

If I have the "off" and "on" positions correct, then how long is the "off" time, and how long is the "on" time ?

Reply to
MoPar Man

Story so far:

2001 Dodge ram short cab long box 5.2L/318 V-8 with overhead information console. Very low miles (about 20k) usually parked every night in a garage sometimes not driven for a week or two at a time. Usually not driven at all in winter. Was working fine, was parked in the driveway, stayed out during a couple of torrential storms (a few days ago) and for the past 2 days it will crank but doesn't run.

It displays "no bus" in the odometer, and is showing "CCD" on the overhead display where the fuel DTE and MPG readings should be. When the ignition is turned on, all guages show some activity. Battery moves to 8 volts, temp moves to 55, oil pressure moves to 0, and even the fuel guage moves a little (but not to the zero or E mark).

Battery volts (as measured with a meter) is showing 12.15 volts with nothing turned on, and 12.05 volts when key is turned to ignition position. DRL (daylight running lights) come on as normal when key is in ignition position. All fuses in the engine compartment and under the small cover at the drivers-side dashboard position are good. When I crank the engine, it turns over very fast, but doesn't start.

Under the hood, I discovered that the gasket/rubber weatherstripping that runs across the top of the firewall was completely off and laying across the back of the engine/air cleaner. It appears to only be a press-fit (no glue or contact cement). Therefore any rain that went between the hood and windshield could easily flow into the engine compartment. It's been dry for the past 2 days, there is no evidence of water pooling. Everything is bone dry.

I have a Haynes repair manual for Dodge Ram 1994-2001, and if the wiring diagrams are correct then the fuel guage is a simple circuit that is not dependent on a computer or the system bus - so it should be indicating something above the empty mark (which it doesn't). That manual doesn't have a good explanation of the instrument console wiring or connections. I don't think that manual is up-to-date for

2000/2001 Ram models.

I've disconnected the battery twice (each for about 15-20 minutes) and the second time I unplugged 3 large cables from the PCM and removed the PCM from the firewall. Contacts appear clean and not a hint of corrosion on either the cable ends or the PCM. I removed 4 screws holding the cover of the PCM and observed a layer of rubber (felt a little like jello) potting compound covering the circuit board. No obvious water intrusion into or under the protective layer. No components seemed dammaged.

When performing this sequence:

I get the following codes:

Where exactly is that? What do I have to take apart or unscrew to get to an access point?

Where are they?

How many wires is the CCD data bus? What colors are they? Where are their access points?

Don't think I'm gonna be able to do that.

Or that.

Again, no can do.

Ditto.

What is the ACM? Where is it?

Where is it?

What's a CAB? Where is it?

Where is it?

Reply to
MoPar Man

Update:

According to this web site:

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Only Dodge Ram's 94 - 97 will flash the codes according to the on-off sequence. Since mine is a 2001, I guess that explains why it's not working and I'm not seeing any codes.

I checked for 5V at the MAP and TPS and it was there in both cases. With one or the other still plugged in, I was getting 5V and no change in the over-all situation.

The Tranny speed sensor was giving me 12V (the Haynes book is saying

8?).

I guess I'll have to see if there's a cheap scan tool available, or make one:

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Reply to
MoPar Man

Reply to
miles

Exactly.If you have a bus failure you cant communicate with certain modules. If it is a total bus failure you can communicate with any modules. Just curious but Mopar man, did you check the connection as I stated?

Glenn Beasley Chrysler tech

Reply to
maxpower

This probably isn't a high priority on your list but the weatherstripping can be tightened up by squeezing the weatherstrip channel with pliers. Don't crimp it closed too tight or you won't be able to get it back on.

Reply to
Nosey

Well, that's next. I take it that the C130 is not the connector that plugs directly into the PCM (powertrain control module) but is somewhere else in the engine compartment? I've already checked the 3 connectors that plug into the PCM, and they seem perfectly fine, as does the ground connection of the PCM.

It's the PCM that's not communicating with the instrument cluster - correct?

Are there any fuses anywere for these systems that are NOT in the engine compartment fuse module or the side-access dashboard compartment?

Reply to
MoPar Man

Update:

Put all the tools away last night around 10 pm, closed up and locked the truck for the night.

This morning (9:30 am) opened the truck, stuck the key in the ingition and turned it to ignition position. Guages all went to their normal positions - even the fuel guage went to where it should be (1/2 tank).

Ok, so I'll try the off-on off-on off-on thing with the key.

Yup, it works, I get these codes:

P0123 (Throttle Position (TP) Sensor Circuit High Voltage) P1687 (P1687 Driver 5 Line 7)

Alternate descriptions of 1687:

No Cluster BUS Message No J1850 messages received from the Mechanical Instrument Cluster (MIC) module

No MIC BUS Message No CCD/J1850 messages received from the Mechanical Instrument Cluster (MIC) module

No messages received from the Mechanical Instrument Cluster module

The 123 code I can understand - since I did disconnect the TP connector to check for 5V at the connector - but I plugged it back in so I guess the code needs to be cleared?

What exactly is the 1687 code?

I'm thinking the truck will now start, but I'd really like to know what caused this problem.

M>

Reply to
MoPar Man

Did you read my reply?

I've already checked the 3

Reply to
maxpower

Didn't I quote it in the previous post?

Update:

As I previously reported, the fuel guage was responding when I switched to the ignition position and I was able to get fault codes from (I guess?) the PCM.

I started the engine, and it fired right up. I re-positioned the truck in the driveway, and while it was still running the fuel guage dropped back to below empty and the "no buS" message was being shown by the odometer and the CCD message was being displayed on the overhead display. Engine was still running fine.

I shut the engine off, and started it again, and repeated that several times. Each time the engine started just fine, but the "no buS" and CCD messages are still being displayed. Strange.

WTF is going on?

Reply to
MoPar Man

"The C130 connector, the connector that is mounted at the firewall that feeds the inside. (Its a 43 pin connector)"

There is a large cable going through the firewall near the brake booster unit. It passes though the firewall via a large rubber grommet. There is no connector there.

Regarding the ECM (electronic control module) I can't locate it. According to the Haynes book, it's supposed to be "bolted to the left side of the engine block - 1999 and later models".

(Why would they do something stupid like bolting an electronic module directly to the block?)

The diagram shows a module with 2 bundles of cables coming from it. The module seems to be attached to a large plate, and the plate is bolted to the block. A fuel transfer pump is shown - it could be near or in front of the ECM. I can find no such module or large plate anywhere on the block (I looked under the engine too). What is the left side? Is that the driver's side?

Reply to
MoPar Man

I was beginning to reach that conclusion as a result of searching for references to the ECM on the web.

Several times.

Update:

I gave up trying to remove the dashboard cover. I did remove the lower driver-side dash trim, the instrument-cluster trim ring, and removed the instrument cluster. Removed the cluster PC board, no dammaged components (looked brand new), noticed that a couple of LED's weren't installed. Optional indicators I guess - one is labelled (on the PC board) as "water / door" and the other one as "security". No corresponding markings on the cluster bezel. For the hell of it, I soldered a couple of LED's in those positions (along with the necessary resistors). On the cluster display, they would show up above the "check engine" light.

There is a massive connector under the dash that's clipped to a metal bracket coming off the firewall. It's a combination of a large and medium-sized connector. The large one has about 60 contact positions (about 50 are used). Again, they're dry and no sign of corrosion. I re-seated both of them. I believe it's the cable that comes from the engine compartment through a hole in the firewall.

I did all this with the battery being disconnected (for about an hour or two). After cleaning the various plastic surfaces and mounting the cluster, I reconnected the battery, and again there's no change. When switched to the run (ignition) position, the gauges seem to move to their respective zero positions (battery to 8v, etc) and the odometer will eventually display "no buS" and the overhead will display CCD. I can, however, still start the engine (the tach reads zero).

I found the following:

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and thought that perhaps it might be relavent. I do have remote lock/alarm/power seats and windows.

Specifically these symptoms:

- Engine Will Not Start (if equipped with Vehicle Theft Alarm) - No Communication With The DRBIII (No Response from CTM) - Essentially, all CTM controlled devices will not function if the CTM locks-up.

There are 2 connectors to this CTM box which is mounted under the dash. But even when it's unplugged, nothing changes.

Reply to
MoPar Man

I get instrument cluster codes (by pressing the odo shaft when turning the ignition to on), but not PCM codes (by the 3-times off-on with the ignition key).

The cluster codes (if that's what they're called) were these:

900 920 921 940 950

Initially when this problem first appeared, the engine would turn over but wouldn't start. Then after an evening just sitting there, the problem completely went away for about a minute, during which time the engine did start, the guages worked, and I was able to get the odo to flash the (PCM?) codes using the 3-times off-on key sequence. Then the guages died and the problem came back (no buS, CCD) except that the engine now starts (but the guages still don't work).

I've been out of town for the past 2 days, during which time the truck has been in the garage (and out of the rain), and the problem is still there, but as mentioned above at least the engine now starts every time I try it (meaning that the PCM is working?).

During the brief time the problem went away, the PCM (?) codes I was getting were:

P0123 (Throttle Position (TP) Sensor Circuit High Voltage) P1687 (P1687 Driver 5 Line 7)

Alternate descriptions of 1687:

No Cluster BUS Message No J1850 messages received from the Mechanical Instrument Cluster (MIC) module

No MIC BUS Message No CCD/J1850 messages received from the Mechanical Instrument Cluster (MIC) module

No messages received from the Mechanical Instrument Cluster module

The P0123 code I can understand - since I did disconnect the TP connector to check for 5V at the connector - but I plugged it back in so I guess the code needs to be cleared?

What exactly is the P1687 code?

Since the cluster is housed in a plastic case that's screwed into a plastic dashboard, the grounding must be part of the 2 cluster connectors. Since I removed the cluster and re-installed it, (and the connections looked great) I doubt there's any connector issue at the cluster itself.

The Haynes book shows the circuits for the guages, but it doesn't show ANY circuits for the electronics in the cluster. The guage circuits don't seem to connect to any of the cluster electronics. If that were true, then the computer wouldn't have any sort of connection to the fuel gauge, in which case you wouldn't be able to read the fuel level through the ODB port (is this the case?).

As I mentioned before, the battery is fine, and when the engine is running, the voltage at the battery is 13.75.

Could the problem be located in the wiring bundle that enters the lower portion of the fuse assembly in the engine compartment, or perhaps some connection inside the fuse assembly?

The battery guage should at least read the battery voltage correctly. Are the guages run off a separate power supply somewhere?

Reply to
MoPar Man

First let me thank maxpower (aka Glenn Measley), miles, FMB, Nosey, TBone, Tom Lawrence, and Joe Brophy for the wealth of information and the detailed answers to my technical questions about the Chrysler Data Bus (tm)(C). My special thanks to Glen for giving me the encouragment to continue diagnosing this problem in my own driveway.

To recap:

2001 Dodge ram, short cab, 5.2L, 2WD, all options.

Truck ran fine one day, was parked overnight, there was rain that day and night, then the next morning engine would turn over but not start. After 2 days and some poking around (disconnecting/reconnecting various connectors) engine would start and briefly the guages worked for about a minute, then went dead, but engine could then be started at will after that.

When ignition is switched to on, odometer displays "no buS" and the overhead console displays "CCD".

Not having a proper wiring diagram, I focused on the wiring to the instrument cluster (MIC). There are 2 connectors (10 pins each) and after identifying all the ground and power pins, there were about 6 pins that were candidates for being "the bus". One of those pins was showing 40 ohms to ground, which I thought was strange.

I metered each of those 6 to the 3 connectors at the PCM and found that only 2 of them did indeed go to the PCM. As I suspected from examining much of the dashboard wiring, those wires are always a twisted pair - indicative of some sort of differential signaling, and I suspected they were indeed "the bus". One of those wires was the one showing 40 ohms to ground, and now I see it's showing 40 ohms to a third pin at the PCM (on a different connector).

Ok, so what I do next is this: with the 3 connectors at the PCM already off, I disconnect as much of that cable as possible. That basically means to disconnect it's opposite end from the main fuse module beside the battery (it's a big square connector with a hold-down bolt in the middle). Ok, I'm still reading 40 ohms - so what's going on? Under the truck, I disconnect a cable going to the transmission (it's got maybe 10 wires) and discover that one of those wires is the one making a 40-ohm connection to one of the bus wires (this is with all connectors still disconnected).

Ok, time to cut the main cable away from the firewall and remove all the black tape and physically inspect the twisted-pair bus wires. I do this all the way to the connector at the fuse module, and still get

40 ohms. The last thing is to take apart the square fuse-module connector. I do this, and as I manipulate the outer cover, the 40-ohm connection goes away. I manipulate the wires and manage to make the 40-ohm connection come and go.

I look closely at where the bus wires go inside this connector, and where the mystery wire to the transmission goes, and it turns out they're right beside each other. But what's really wierd is that there's no indication that they're touching. No corrosion, no chafing, no bared insulation. Very strange.

So I re-position the wires and close up and re-tape the connector, then re-tape the entire main cable back to the PCM connectors, and re-install all connectors and assemblies in the dash that I took apart.

Needless to say, the MIC worked fine, and no PCM or MIC codes were displayed when I tried the various diagnostic code reporting methods.

I'm thinking that this problem had nothing to do with the rain that happened the night before this problem started, but I still don't know why the engine wouldn't start during the early phase of this situation.

I'm glad I did this, and not simply take it to the dealership and maybe those monkeys wiggle something and the problem goes away only to come back later. At least now I know where to look if it happens again.

Reply to
MoPar Man

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