Engine/Transmission (1998.5 - 2002) I’m begging could some one please help? I’m have a major problem

[grass hopper]

Grass Hopper:



You can take your truck to an Advance Auto Parts and they will put an OBDII scanner on your truck to read the ECM code. The PCM code is only a companion code saying you have code(s) stored in you ECM.



You can spend a lot of money chasing problems... the ECM code(s) can halp narrow down the issue.



Good luck,



Wiredawg

stopped by Advance last weekend & the guy told me that they could not scan the truck sorry so i asked if he could check my battery's so he did & they were on there way so i replaced them. but today i stopped by autozone and they scanned the truck but still no codes. so i stopped by my friends shop and he scanned it again with his snap-on scanner. scanned the ECM & other's but still no codes. could a fuel filter that is getting pluged up cuase any thing like this? man i am getting a headache again with this truck. thank all of ya'll for ya'll help so far. as i am sure it will get fixed soon.

 

[MCummings]

#ad






The ECM is bolted to the engine block behind the fuel filter.



REMOVAL



1. Record any Diagnostic Trouble Codes (DTC's) found in the PCM or ECM. To avoid possible voltage spike damage to either the Powertrain Control Module (PCM) or ECM, ignition key must be off, and negative battery cables must be disconnected before unplugging ECM connectors.

2. Disconnect both negative battery cables at both batteries.

3. Remove 50-way electrical connector bolt at ECM. Note: Connector bolt is female 4mm hex head. To remove bolt, use a ball-hex bit or ball- hex screwdriver such as Snap-On(R) 4 mm SDABM4 (5/32" may also be used). As bolt is being removed, very carefully remove connector from ECM.

4. Remove three ECM mounting bolts and remove ECM from vehicle. INSTALLATION Do not apply paint to back of ECM. Poor ground will result.



1. Clean ECM mounting points at engine block.

2. Position ECM to engine block and install 3 mounting bolts. Tighten bolts to 24 Nm (18 ft. lbs. ) .

3. Check pin connectors in ECM and 50-way connector for corrosion or damage. Repair as necessary.

4. Clean pins in 50-way electrical connector with a quick-dry electrical contact cleaner.

5. Very carefully install 50-way connector to ECM. tighten connector hex bolt.

6. Install battery cables.

7. Turn key to ON position. Without starting engine, slowly press throttle pedal to floor and then slowly release. This step must be done (one time) to ensure accelerator pedal position sensor calibration has been learned by ECM. If not done, possible DTC's may be set.

8. Use DRB scan tool to erase any stored companion DTC's from PCM.



-------------



Hopefully this can help.



Merrick

 

[grass hopper]

#ad






The ECM is bolted to the engine block behind the fuel filter.



REMOVAL



1. Record any Diagnostic Trouble Codes (DTC's) found in the PCM or ECM. To avoid possible voltage spike damage to either the Powertrain Control Module (PCM) or ECM, ignition key must be off, and negative battery cables must be disconnected before unplugging ECM connectors.

2. Disconnect both negative battery cables at both batteries.

3. Remove 50-way electrical connector bolt at ECM. Note: Connector bolt is female 4mm hex head. To remove bolt, use a ball-hex bit or ball- hex screwdriver such as Snap-On(R) 4 mm SDABM4 (5/32" may also be used). As bolt is being removed, very carefully remove connector from ECM.

4. Remove three ECM mounting bolts and remove ECM from vehicle. INSTALLATION Do not apply paint to back of ECM. Poor ground will result.



1. Clean ECM mounting points at engine block.

2. Position ECM to engine block and install 3 mounting bolts. Tighten bolts to 24 Nm (18 ft. lbs. ) .

3. Check pin connectors in ECM and 50-way connector for corrosion or damage. Repair as necessary.

4. Clean pins in 50-way electrical connector with a quick-dry electrical contact cleaner.

5. Very carefully install 50-way connector to ECM. tighten connector hex bolt.

6. Install battery cables.

7. Turn key to ON position. Without starting engine, slowly press throttle pedal to floor and then slowly release. This step must be done (one time) to ensure accelerator pedal position sensor calibration has been learned by ECM. If not done, possible DTC's may be set.

8. Use DRB scan tool to erase any stored companion DTC's from PCM.



-------------



Hopefully this can help.



Merrick

thanks for this it will help. would this also be the ground for the ECM & fuel pump?

 

[MCummings]

Yes for the ECM. Seems the ECM is grounded to the block through the ECM's case. Might just be a loose ECM.



The fuel pump is grounded internally in the ECM.



Merrick

 

[grass hopper]

Yes for the ECM. Seems the ECM is grounded to the block through the ECM's case. Might just be a loose ECM.



The fuel pump is grounded internally in the ECM.



Merrick

ok i will check that after work tomorrow. A friend loaned me a car for a few days until i get it fixed. so i'm good. was thinking about this grounding thing and today or for that the last few days it has been raining here and the truck has slowly been getting worst as far as the pedal thing & the LP not working. maybe thats what's doing it a loose ECM?

thanks

 

[Huff N Puff]

Yes for the ECM. Seems the ECM is grounded to the block through the ECM's case. Might just be a loose ECM.



The fuel pump is grounded internally in the ECM.



Merrick

Thats not true.

The Fuel pump is supplied positive power by the ECM and is grounded on the left rear of the engine,this ground is also the ground for the fuel heater and the cummins bus. Its a black and white wire. There is also a sensor ground for most of the sensors including the APPS. This black and blue wire is grounded through the ECM at pin 4 of the ECM. The main ECM grounds are pins 49 and 30. If the ECM grounds are poor it won't be able to ground the sensors properly. If you check any of the sensor grounds, black and blue wires with a volt meter and it reads more than 50millivolts,the ground is poor. Voltmeter needs to be on the lowest possible setting.

 

[DPrew]

I just went back to a shop that hadn't done any work for me in a while and was very impressed with one of the veteran diesel mechanics Andre had hired. The shop is Andre's Automotive 303-9796 on Hwy 71 just west of Bastrop. Andre's mechanic diagnosed problems more than 1/2 dozen other mechanics has overlooked in the last few months. Andre's is also open 1/2 day on Saturday which can be convenient.



Older Diesels can occasionally set you back some bucks for repairs but it's still cheaper than a new one.

 

[grass hopper]

I just went back to a shop that hadn't done any work for me in a while and was very impressed with one of the veteran diesel mechanics Andre had hired. The shop is Andre's Automotive 303-9796 on Hwy 71 just west of Bastrop. Andre's mechanic diagnosed problems more than 1/2 dozen other mechanics has overlooked in the last few months. Andre's is also open 1/2 day on Saturday which can be convenient.



Older Diesels can occasionally set you back some bucks for repairs but it's still cheaper than a new one.

thanks for there info i will give them a call

 

[David_VT]

To the experts (as I am not one):

What is the control loop that holds this truck at a set idle?

The TPS voltage at startup sets the reference for what the ECM will consider 'idle'.

We all know that the idle is being controlled to a set RPM. An example in my 5 speed is running on flat ground with the truck in say 3rd gear and letting the truck idle. The engine will add fuel to maintain the idle rpm speed if we encounter a slight grade.

Where is that RPM signal picked up?

When we touch our go pedal, the control loop must discard the idle reference speed and answer the command of the right foot.

Is this where the fuel mapping to TPS voltage comes in?



Anyways, I am curious about what should occur when we go from the idle control loop to a pedal position. Is the ECM still trying to match a rpm to the TPS voltage?



Could this RPM sensor be the root cause of this problem?

 

[NoSeeUm]

Off Topic:



The VP44 trucks are essentially "fly by wire" meaning external sensors talk to the ECM and then the ECM talks to the VP44.



Depending on the year, a cam and / or crankshaft position sensor supplies a pulse to the ECM that indicates the rotational position of the engine. Typically the zero and / or specific timing point(s) and this is how the ECM calculates injection timing as well.



To get engine RPM the ECM basically counts pulses over time to create a computed value (for RPM).



As to the minimum governed (idle) rpm, that calculation occurs in the ECM also. If the acutal value goes below the setpoint value (about 850 rpm) then the ECM tells the VP44 to increase a bit more fuel etc... You probably noticed this can be very harse at times, the ECM fuels aggressively to keep RPM's above idle.



This is also how the cruise control works on manual transmissions. I believe the ECM is using MPH as the control variable vice RPM directly. Where basically vehicle speed is calculated the same way as RPM where the ECM recieves pulses, as the drive train rotates, and counts pulses over time. If you watch the throttle position output (APPS) on cruise control it will always be zero.



Jim

 

[grass hopper]

not sure if this will help but the other day when i stoped by my friends shop to have him scan the truck as it was acting up. i wrote these numbers down.

COOLING Temp 151*F ---1. 3 volts

IAT Temp 100*F ---2. 5 volts

Intake HTR 138*F ----- #1 off & #2 on (#2 did turn off about 1min later but it did not change the pedal)

CKP 803

RPM 801



this is all i wrote down off of his snap-on scanner at the time becuase he move threw that thing fast.

 

[grass hopper]

Yes for the ECM. Seems the ECM is grounded to the block through the ECM's case. Might just be a loose ECM.



The fuel pump is grounded internally in the ECM.



Merrick

well this mite be a little early but i wanted to let ya'll all know & give every one a big thank you for all of ya'll help.

so THANK YA'LL & a really big THANK YOU TO Merrick. he sent me a ECM so icould try it on my truck to see if it would fix the problem. so i removed the old one and installed the one he sent me (took about 30 min start to finsh) & so far it has fixed it. drove it around town then came back home and shut it off cleaned up all my tools and put them away. then went back to the truck and started her up gave it a little pedal and she idled up just like she should so i drove around again for about 15min and came home and shut her down waited about 5mine then restarted her gave her some pedal and it worked just like she should. did this a few more times and every time the same thing. it all good :>) i will keep ya'll posted over the next few day if some thing changes. but i would really like to say thank you to every one of ya'll ;>)

 

[JLight]

Cool Grasshopper! My friends Buddy has his truck fixed. They took it to the dealer where he bought it and unknown to me this truck has had injector issues. Seems there were bad injectors back in 02? Well anyway they put it on the computer and low and behold all the inj were bad! Dodge wanted 580 a hole and he got them from a diesel shop in caz for 320 remans Put them in and problem solved! No more run away and unwanted black smoke!

 

[MCummings]

Thats not true.

The Fuel pump is supplied positive power by the ECM and is grounded on the left rear of the engine,this ground is also the ground for the fuel heater and the cummins bus. Its a black and white wire. There is also a sensor ground for most of the sensors including the APPS. This black and blue wire is grounded through the ECM at pin 4 of the ECM. The main ECM grounds are pins 49 and 30. If the ECM grounds are poor it won't be able to ground the sensors properly. If you check any of the sensor grounds, black and blue wires with a volt meter and it reads more than 50millivolts,the ground is poor. Voltmeter needs to be on the lowest possible setting.

I stand corrected.



Thank You.



I'm glad you got your truck workin' grass hopper. We'll see how the truck responds for the next few days. The patient may or may not accept the heart transplant. :-laf



Merrick