Archived 2001 dead - SE Michigan

[SS]

Well I tried to get by without resorting to 911 - truck is dead in my driveway and holiday season does not allow for the most time to stay and work on it and I need to get it running soon.



Truck is a 2001. 5 6-speed with a Edge Comp without the injection pump tap. I did tap it previously and had issues with losing connection and have now soldered the original wire together. Died while driving it - almost like running out of fuel (checked that). It will crank, but will not fire. It had done the same thing when the injection pump wire became disconnected earlier - reconnected it and fired right up. Now codes 1694 and 1693 are active (also had 1689 and 0237 previously but may or may not be related). The "wait to start" light is acting flaky - sometimes doesn't light at all (35* weather), sometimes for a second or two, sometimes flashes while cranking. The tach and oil pressure also seem a bit flaky as they will sometimes stay at 1100 RPM/50 psi when releasing the key to the run position after cranking but not starting. I cleaned all of the terminals on the grid heater/relays and also the ECM, PCM, and injection pump connectors. Also removed and cleaned IAT sensor. Lift pump initially appeared to be working, but has since stopped. It does not come on with the key or after the starter is bumped. I just jumped it with 12 volts and it does operate. I jumped the injection pump pins 6 and 7 and the truck started and idled perfectly (this may have been while the lift pump WAS operating. ) I changed the filter and now may have introduced air into the system. Brand new batteries and I cleaned the terminals when they were installed and used protectant spray on them. Cleaned the ground connections, except the ECM and PCM ground connectors at the passenger side battery (couldn't get either one apart).



About 2 years ago I had a "no bus" signal on the odometer and lost all dash functions (but no other symptoms) 2 or 3 times, but not since.



I'm leaning towards ECM as the cause, but am looking for other causes or ways to further verify ECM. I will try to trace the lift pump wiring to make sure it is OK. Thanks for any more input.



See previous thread: initial post hopefully I remembered all of the details.

 

[Missouri Mule]

Have you checked to see if you have fuel flowing to the injectors yet?

1693=DTC dectected in ECM or PCM

1694=No CCD messages received from ECM

1689=No communications between ECM and Injection Pump Module

0237= Map sensor voltage to Low



DTC= diaganostic trouble code: fault code set by control module when sensor data is not as expected.

CCD= Chrysler collision detection: data bus system used by the airbag and anti-lock brake systems.



I would check into the ECM/DAta bus system.

 

[wtfd6]

where in se michigan are you?

 

[SS]

Thanks for the replies - I have searched (and searched) on similar issues without finding a concrete solution. I'm not sure what else to check in the ECM circuit. I did see a few posts about connectors behind the dash relating to "no bus" signals - not sure that's my issue, but I'll have a look.



I think I have to figure out the lift pump issue before I can tell if it's getting fuel to the injectors - it was when I jumped pins 6 & 7 on the connector since it idled fine. Now the lift pump is not running. I suppose it's possible that whatever the communication issue is/was to the injection pump is now solved with cleaning all of the contacts since the 1689 code is not active. It hasn't been started though, so it may not know if there is an issue.



I'm north of Ann Arbor.

 

[SS]

Lift pump connector (when disconnected from pump) is still at 9 volts keyed on or cranking. It doesn't time out - I believe it normally times out around 2 seconds when keyed on or 30 seconds after cranking. Can't find any loose connectors or other wiring problems. I will check the ECU ground and power at the connector to see that it's at 12 volts.



So is 9 volts enough to run the lift pump?

Shouldn't the lift pump voltage from the ECU time out?

Or does it need to be connected to the pump to sense a load?

Anybody seen this behavior?



I could try jumping the injection pump again, but now I think I should jump the lift pump at the same time. I'm afraid of trying to run it with the lift pump not operating correctly. Maybe jumping the lift pump would be enough, but I've almost convinced myself that there is something else going on? Guess that's a bad diagnostic method and maybe I'll try just powering the lift pump.



Can I install an ECU from the same model year truck? I don't know of another way to verify that it works and I have a couple friends with the same truck. Looks like maybe I'll be buying 2 ECU's if that doesn't work out.

 

[Bob Wagner]

Can I install an ECU from the same model year truck? I don't know of another way to verify that it works and I have a couple friends with the same truck. Looks like maybe I'll be buying 2 ECU's if that doesn't work out.

Yes you can

 

[wtfd6]

as far as the 9 volts, what is battery voltage? it should be the same at the lift pump. the ecm triggers a relay. I havent ever heard about jumping terminals on the ip. but as always, I am still learning. I know guys that tried ecms from other trucks. sounds possible. but if it is a bus communications problem the truck wont run. I get the no bus message in extreme cold but it has never killed the entire bus on my truck. wish I could run up there, I would help.

Mark

 

[SS]

Thanks Bob - I've already been considering calling you if it turns out to be ECM. Looks like a little research might be in order there too - if I have to get a new ECM it might as well be an upgrade!



Thanks Mark - one of my buddies agreed to swap ECM's tomorrow if needed. From the wiring diagram it appears that the lift pump runs directly from the ECM without a relay.

 

[bighammer]

I'm north of Ann Arbor.

So am I!!

 

[SS]

So am I!!

Great! Are you keeping the beer cold for me then? :-laf



Well... I should probably at least wait until the truck is running...

 

[cyborg]

Are we running yet?

Any updates?

 

[SS]

Not yet - had a bit of a logistical problem today trying to get together with a similar truck to swap ECU. I think he might be afraid to have 2 down trucks! I'm hoping for tomorrow - otherwise it starts back into the work week again...



I will post the solution - kind of frustrating to read over old posts and not know if the story has a happy ending.

 

[SS]

Ecu!

Swapped ECU's with a like truck. The wait to start light behaved normally, the lift pump kicked on, and the engine started almost immediately (probably had a bit of air in the lines from the filter change). The other truck runs fine after the swap back also.



The ECU seems to be the problem. I will post up in the 2nd generation forums when I get a replacement. Thanks to those who provided advice.



Case closed.