Engine/Transmission (1998.5 - 2002) 2001 24V no start — electrical power issues

[JLandry]

Gordon,

Spare me from reading the entire thread again to find out...

Did you already check the ECM ground wires?

John L.

 

[Gordon Maney]

Gordon,

Spare from reading the entire thread again to find out...

Did you already check the ECM ground wires?

John L.

I admit to not knowing where those wires are located. The ECM has no visible ground lead like the PCM. Isn't that correct?

You are meaning leads that run to the connector?

 

[Sticks]

Attached.

Page 1, post #10 PDF attachment P1694 diagnostics

John L.

Don't condemn that ECM yet. You still need to verify that the CCD wiring is intact. There is a work around to do this without a DRB III, not easy but doable.

I admit to not knowing where those wires are located. The ECM has no visible ground lead like the PCM. Isn't that correct?



You are meaning leads that run to the connector?

IIRC the PCM and ECM will get ground from both the mount and a wire or two in the harness.

 

[Gordon Maney]

Don't condemn that ECM yet. You still need to verify that the CCD wiring is intact. There is a work around to do this without a DRB III, not easy but doable.

What is the work-around?

IIRC the PCM and ECM will get ground from both the mount and a wire or two in the harness.

I am thinking my grounds are good, but admit to not knowing how to further pursue that issue.

 

[Sticks]

Step 3

Ignition Off
Disconnect the Engine Control Module Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between CCD Bus (+) Circuit and ground.
Ignition on, engine not running.
With the DRB, select *body,* then the type of cluster you have.
Note: Bus test will automatically run.
Does the DRB show *short to ground*?
Yes ! Go To 4
No ! Repair open CCD Bus (+) Circuit from ECM to Data Link
Connector.
Perform Powertrain Verification Test VER-2A.

Step 4

Ignition Off
Disconnect the Engine Control Module Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between CCD Bus (-) Circuit and ground.
Ignition on, engine not running.
With the DRB, select *body,* then the type of cluster you have.
Note: Bus test will automatically run.
Does the DRB show *short to ground*?
Yes ! Go To 5
No ! Repair open CCD Bus (-) Circuit from ECM to Datalink Connector.
Perform Powertrain Verification Test VER-2A.

Step 5

Ignition Off
Disconnect the Engine Control Module Connector.
Note: Check connectors - Clean/repair as necessary.
Using an ohmmeter, measure the Ground Circuit Cavity 30 to ground.
Is the resistance below 10. 0 ohms?
Yes ! Go To 6
No ! Repair the open Ground Circuit.
Perform Powertrain Verification Test VER-2A.

Without a wiring diagram handy, These tests are checking the 3 wires for this circuits operation. I am not 100% sure of the resistance for the (+) and (-) wires in the CCD circuit, but I would say they should be less than 10 ohms (I'd prefer < 5 ohms on a quality DVM) as well, checking each wire at the PCM and the ECM connections. EDITED TO ADD - and directly to ground

Mr Landry may be able to give a better description of the procedure, or correct me if I am wrong.

I'd be interested in reading the Powertrain Verification Test VER-2A procedure as well. The whole point of running the diagnostics for the code is to verify all possible problems. The ECM has to fail all steps before a death certificate is written. There is no shortcut to step 6 - Replace ECM

So far all we know for sure is the ECM is getting power, and the PCM is complaining that the ECM is being unsociable.

Right now the chances are high that the ECM has gone TU, and there seems to be a lot of failures of late being posted. However, in my years of working on trucks, I have only had 1 ECM failure (nothing like getting a dead core from the dealer instead of a reman #@$%! ), and that was 99% likely due to the owner using a ECM programmer instead of a plug and play chip/box for performance enhancements.

 

[Gordon Maney]

Step 3


Step 4



Step 5



Without a wiring diagram handy, These tests are checking the 3 wires for this circuits operation. I am not 100% sure of the resistance for the (+) and (-) wires in the CCD circuit, but I would say they should be less than 10 ohms (I'd prefer < 5 ohms on a quality DVM) as well, checking each wire at the PCM and the ECM connections. EDITED TO ADD - and directly to ground

Mr Landry may be able to give a better description of the procedure, or correct me if I am wrong.

I'd be interested in reading the Powertrain Verification Test VER-2A procedure as well. The whole point of running the diagnostics for the code is to verify all possible problems. The ECM has to fail all steps before a death certificate is written. There is no shortcut to step 6 - Replace ECM

So far all we know for sure is the ECM is getting power, and the PCM is complaining that the ECM is being unsociable.

Right now the chances are high that the ECM has gone TU, and there seems to be a lot of failures of late being posted. However, in my years of working on trucks, I have only had 1 ECM failure (nothing like getting a dead core from the dealer instead of a reman #@$%! ), and that was 99% likely due to the owner using a ECM programmer instead of a plug and play chip/box for performance enhancements.

Aren't these the steps from the 1694 code procedure? I don't have the DRB tester, so I don't see how this is a work-around.

This may qualify for the dumb question of the day, but... . which wires are the + and - wires in the CCD circuit?

 

[Sticks]

These steps are the workaround.

Without a wiring diagram handy, These tests are checking the 3 wires for this circuits operation. I am not 100% sure of the resistance for the (+) and (-) wires in the CCD circuit, but I would say they should be less than 10 ohms (I'd prefer < 5 ohms on a quality DVM) as well, checking each wire at the PCM and the ECM connections. EDITED TO ADD - and directly to ground

The DRB is going to tell you if the PCM connections are responding to the artificial faults that you are making at the ECM connector. I. E. - You disconnect the ECM, jumper the (+) line of the CCD circuit to ground. The PCM replies either "Yes, I see that the line is shorted to ground, ergo the wire is good, please go to the next step. " - or - "No, I do not see that the line is shorted to ground. 1. Did you jumper the correct wire? 2. The wire must be broken, please repair. "

By using a DVM to test the continuity (ohms) of each wire ( + and - ) on each end, between each other, and directly to ground, you are getting the desired results.

Again, I do not have a wiring diagram. The following is an example only.

ECM Connection - Pin 1 is the CCD (+) line, pin 10 is the CCD (-) line.
PCM Connection - Pin 5 is the CCD (+) line, pin 15 is the CCD (-) line.

DVM set to Ohms, ECM and PCM disconnected, ignition off. NOTE - OL means what the DVM ohm reading is when the two test leads are not touching anything. When testing pins, to not touch any exposed wires or test leads (other than the handle) as this will give false readings. With a DVM set to ohms, you can grab each lead and you will get a reading. Your body will act as a conductor.

1. Test ECM pin 1 to PCM pin 5 = A. < 5 Ohms = Wire OK. B. > 10 ohms = broken wire.
2. Test ECM pin 10 to PCM pin 15 = A. < 5 Ohms = Wire OK. B. > 10 ohms = broken wire.
3. Test ECM pin 1 to ECM pin 10 = A. < OL (getting a reading) = Wires shorted to each other. B. OL. (no reading) = wires not shorted to each other.
4. Test ECM pin 1 to battery ground, and/or known good ground on vehicle = A. Any reading above OL, wire shorted to ground. B. OL ,wire OK.
5. Repeat step 4 for ECM pin 10
6. Test ECM pin 1 to every other pin in the connection. A. Any reading above OL, wire shorted to pin tested. B. OL, wire OK.
7. Repeat step 6 for ECM pin 10.

Testing each and every other pin in the connections will tell you if the CCD wires are shorted to another circuit, or battery (+).

 

[Gordon Maney]

These steps are the workaround.



The DRB is going to tell you if the PCM connections are responding to the artificial faults that you are making at the ECM connector. I. E. - You disconnect the ECM, jumper the (+) line of the CCD circuit to ground. The PCM replies either "Yes, I see that the line is shorted to ground, ergo the wire is good, please go to the next step. " - or - "No, I do not see that the line is shorted to ground. 1. Did you jumper the correct wire? 2. The wire must be broken, please repair. "

By using a DVM to test the continuity (ohms) of each wire ( + and - ) on each end, between each other, and directly to ground, you are getting the desired results.

Again, I do not have a wiring diagram. The following is an example only.

ECM Connection - Pin 1 is the CCD (+) line, pin 10 is the CCD (-) line.
PCM Connection - Pin 5 is the CCD (+) line, pin 15 is the CCD (-) line.

DVM set to Ohms, ECM and PCM disconnected, ignition off. NOTE - OL means what the DVM ohm reading is when the two test leads are not touching anything. When testing pins, to not touch any exposed wires or test leads (other than the handle) as this will give false readings. With a DVM set to ohms, you can grab each lead and you will get a reading. Your body will act as a conductor.

1. Test ECM pin 1 to PCM pin 5 = A. < 5 Ohms = Wire OK. B. > 10 ohms = broken wire.
2. Test ECM pin 10 to PCM pin 15 = A. < 5 Ohms = Wire OK. B. > 10 ohms = broken wire.
3. Test ECM pin 1 to ECM pin 10 = A. < OL (getting a reading) = Wires shorted to each other. B. OL. (no reading) = wires not shorted to each other.
4. Test ECM pin 1 to battery ground, and/or known good ground on vehicle = A. Any reading above OL, wire shorted to ground. B. OL ,wire OK.
5. Repeat step 4 for ECM pin 10
6. Test ECM pin 1 to every other pin in the connection. A. Any reading above OL, wire shorted to pin tested. B. OL, wire OK.
7. Repeat step 6 for ECM pin 10.

Testing each and every other pin in the connections will tell you if the CCD wires are shorted to another circuit, or battery (+).

Do CCD+ and B+ mean the same things? I regret to say I have wiring diagrams and am unsure regarding how to engage with what you describe. I feel pretty ignorant just now.....

 

[Gordon Maney]

I have been up since 4AM, so my mental function is a bit down.

I continued to ram my head against the manual and had a flash of comprehension, however brief.

Using the pin-out for the ECM, I learn...
CCD bus- is pin 40
CCD bus+ is pin 41

Using the pin-out for the PCM, I learn...
CCD bus- is pin 28
CCD bus+ is pin 30

So, I will go out to the shop, fire up my little friend, the hanging heater [... . it is -12F here] and perform resistance tests on the bus- and bus+ circuits defined as per above.

 

[Sticks]

You got it.



ECM

CCD bus- is pin 40

CCD bus+ is pin 41



PCM

CCD bus- is pin 28

CCD bus+ is pin 30



1. Test ECM pin 40 to PCM pin 28 = A. < 5 Ohms = Wire OK. B. > 10 ohms = broken wire.

2. Test ECM pin 41 to PCM pin 30 = A. < 5 Ohms = Wire OK. B. > 10 ohms = broken wire.

3. Test ECM pin 40 to ECM pin 41 = A. < OL (getting a reading) = Wires shorted to each other. B. OL. (no reading) = wires not shorted to each other.

4. Test ECM pin 40 to battery ground, and/or known good ground on vehicle = A. Any reading above OL, wire shorted to ground. B. OL ,wire OK.

5. Repeat step 4 for ECM pin 41

6. Test ECM pin 40 to every other pin in the connection. A. Any reading above OL, wire shorted to pin tested. B. OL, wire OK.

7. Repeat step 6 for ECM pin 41.



Testing each and every other pin in the connections will tell you if the CCD wires are shorted to another circuit, or battery (+).

 

[Sticks]

Also you still have Mr Landry's question - did you check the ground line in the connector?

 

[Gordon Maney]

Also you still have Mr Landry's question - did you check the ground line in the connector?

It appears there are actually two (2) — they are 30 and 49.

There are several marked sensor ground, but I am thinking that is not what you mean.

 

[Gordon Maney]

Pins 30 and 49 to ground check virtually zero resistance. Less than 1 ohm.

The bus connections are harder. The whole paper clip thing is difficult with no helper. It it not clear how good the other connection is at the moment, with the other connection the one you can't hold in your hands.

Given that, I get about 29 ohms at the bus+ and only once did I get 37 ohms at the bus-. Is the bus- grounded? Experimenting, one ohmmeter lead connected to the turbo casting and the other to the bus- terminal on the ECM connector I got effectively zero resistance.

I have come in to get a larger wire gauge paper clip. I had gone small before as I don't want to risk damaging the connectors.

There are adapters on the PCM connectors that latch onto them in a manner similar to other connectors. I would remove the adapter to get to the deeper part of the connector, but there are four hooks that defy release with only one person and I don't want to destroy the latches.

 

[Gordon Maney]

I am doing no better on the bus negative. Two times I got a reading of about 34 ohms. I don't have confidence in my connections and would like to remove the adapter, but fear destroying it.

Whether related, if I have an ohmmeter lead on the turbo housing and then probe into the PCM connector, I get continuity to termainals 8, 22, and 23, suggesting those are grounded.

If I do that with terminal 32, I get a variation of readings from 6 to 84, with no point seeming a favorite.

I see no way to disconnect this adapter without destroying all the latch features.

Also, minor point, perhaps, but my center connector is white, and the manual entries call every one of them black.

 

[JLandry]

I am doing no better on the bus negative.

Gordon,



I'm just now catching up on this thread since you started checking the CCD bus...



While I'm no electronics wiz (and therefore could be wrong), I don't think it's possible to properly check the CCD bus the way you're doing (using an Ohmmeter) without first disconnecting *everything* attached to it in order to completely isolate the CCD wiring.



Read THIS POST for more info on testing the CCD bus.



Now back to the issue of whether or not the ECM is toast...



You've verified the ECM is getting power and the power signal to turn itself on. You've verified the ground circuits are OK. I believe early on you also verified the ECM is not energizing the lift pump for 25 seconds when you bump the starter (as it should), nor is the VP44 fuel injection pump power circuit being energized when you turn the ignition key to RUN... correct? These later two functions belong to the ECM and are independent of the PCM. So the lack of CCD bus communication between the ECM and PCM is a red herring and irrelevant if the ECM isn't even performing its basic functions.



So it seems to me you've done a good job at verifying the ECM is indeed dead! If this was my truck I think I'd concentrate on figuring out where to get a replacement ECM!



Best regards,



John L.

 

[Gordon Maney]

Gordon,

I'm just now catching up on this thread since you started checking the CCD bus...

While I'm no electronics wiz (and therefore could be wrong), I don't think it's possible to properly check the CCD bus the way you're doing (using an Ohmmeter) without first disconnecting *everything* attached to it in order to completely isolate the CCD wiring.

Read THIS POST for more info on testing the CCD bus.

Now back to the issue of whether or not the ECM is toast...

You've verified the ECM is getting power and the power signal to turn itself on. You've verified the ground circuits are OK. I believe early on you also verified the ECM is not energizing the lift pump for 25 seconds when you bump the starter (as it should), nor is the VP44 fuel injection pump power circuit being energized when you turn the ignition key to RUN... correct? These later two functions belong to the ECM and are independent of the PCM. So the lack of CCD bus communication between the ECM and PCM is a red herring and irrelevant if the ECM isn't even performing its basic functions.

So it seems to me you've done a good job at verifying the ECM is indeed dead! If this was my truck I think I'd concentrate on figuring out where to get a replacement ECM!

Best regards,

John L.

Yes, correct.

Thank you. I will order an ECM Monday.

The procedure in the thread you link to is daunting.

 

[Gordon Maney]

I had a phone visit with a guy who owns an automotive repair business. I phoned him to see where he would buy an ECM. He has, in the past, purchased ECM's repaired or reconditioned by Standard Ignition, buying them from a local auto parts business. It is a business I dealt with for years and still do occasionally, so I am going to inquire there.

During our conversation we talked about the bus and he also said it was impossible to test it without disconnecting everything from it. He went on to talk about a customer's Dodge Caravan that had a problem that would cause it to stop running. This customer used this vehicle as a delivery vehicle for a business. Numerous shops had tried to fix it and could not.

One item connected to the bus was the instrument cluster. The long story short is that there were connections at the instrument cluster that were intermittent, causing the truck to stop. He removed the cluster, resoldered a number of connections on the connector, and the engine has never stopped since.

He also spoke very highly about a subscription service called Identifix, you can view it here IDENTIFIX - SERVICES

 

[JLandry]

I had a phone visit with a guy who owns an automotive repair business. I phoned him to see where he would buy an ECM. He has, in the past, purchased ECM's repaired or reconditioned by Standard Ignition, buying them from a local auto parts business.

WARNING: I think you're going to find the Cummins ECM is not readily available through your local auto parts store. They'll list an "engine computer" (or something similar) in their catalogs at a great price (like $400 or less), but when you get it, you'll find it's actually not a Cummins ECM but a Chrysler PCM... which is the engine computer in other Dodge vehicles when not equipped with a Cummins engine. If it costs less than about $650, it's probably not a Cummins ECM.

During our conversation we talked about the bus and he also said it was impossible to test it without disconnecting everything from it.

True... unless you have access to a Chrysler DRBIII scan tool manufactured by Miller SPX. That device will test the entire CCD bus without disconnecting any components.



Good luck,



John L.

 

[Gordon Maney]

WARNING: I think you're going to find the Cummins ECM is not readily available through your local auto parts store. They'll list an "engine computer" (or something similar) in their catalogs at a great price (like $400 or less), but when you get it, you'll find it's actually not a Cummins ECM but a Chrysler PCM... which is the engine computer in other Dodge vehicles when not equipped with a Cummins engine. If it costs less than about $650, it's probably not a Cummins ECM.

True... unless you have access to a Chrysler DRBIII scan tool manufactured by Miller SPX. That device will test the entire CCD bus without disconnecting any components.

Good luck,

John L.

I felt he was agreeing with your remarks in post 75.