2012 Ram 3500 Cummins Crank No Start - No codes

Andrew Diagnostician Arizona Posted   Latest  
Case Study
Electrical
2012 Ram 3500 ST 6.7L (L ETJ) 6-spd (66RFE) — 3C63DRAL4CG344467
Crank / No Start
No Lift Pump Acuation
No Codes

2012 Cummins 6.7 Died in flight, customer noted no lift pump operation and replaced lift pump, no change - truck towed into my shop. 

Initial observations: 

No stored codes relating to this concern (had a U code for lost comm w/ABS module - stored code not active) 

Lift pump does not come on with key cycle (Lift pump should run for 2 seconds on key up and another 25 seconds after starter engagement) 

Truck is EGR / DPF Deleted w/tune in PCM ← NOTE: THIS PROBLEM IS NOT RELATED TO THE DELETE AND THE DELETE HAD ZERO IMPACT ON THE DIAG - Please keep reading, this applies to all trucks. 

When cranking the fuel rail pressure is commanded to zero. 

using bidirectional controls the lift pump can be turned on. 

After running the lift pump, unplugged the fuel control actuator - normally closed valve, unplugged it defaults to max press. Cranked truck and fuel rail pressure went up to 23,000PSI. 

Checked all fuses found no issues

Connected scan tool and monitored data - See scanshare link:

scanshare​.​io/share/amZIQ9xy…

Noted the key position PID reads correct key position 

Also noted Keyswitch Status PID reads “Off” at all times. 

Known good PCM Swapped in to rule out PCM Failiure - No change

Known good PCM is from a factory truck, remember this truck is deleted and the factory pcm should set circuit codes for all the missing pieces (EGTs EGR valve ect.) factory PCM only set codes for the missing EGT sensors but not the EGR. 

Known good PCM had the same symptom no lift pump fuel pressure commanded to 0. 

Unplugged Injectors to rule out a shorted injector pulling down a logic circuit noted no circuit codes in known good PCM. 

Swapped back in the tuned PCM the truck came in with and found it also doesn't set codes for injector circuits. 

Load tested powers and gounds to PCM:

Note this info is for a NON DEF truck. 

there are 3 powers and 3 grounds in pins 1-6 C2 @ PCM

All load tested good. 2 constant powers and 1 hot in run / start. 

Note there are 2 more switched power wires on pin 70 & 71 C2 @ PCM. 

Found Pin 71 Missing it's switched power. 

Pink / grey wire comes from TIPM on C2 Pin 22 fed by fuse M33 (10a) 

probed wire with circuit connected and the key on about 2 inches from TIPM - wire showed a ground (Load) 

(Wire should have B+) 

Using a Power probe supplied B+ to that wire - truck starts and runs. 

tested the Pin at the TIPM Connector, Key on: No power (circuit was open) there is power at M33 10a fuse and per the diagram there is a straight connection between that pin and the fuse. 

measured circuit resistance between the fuse and the pin on the TIPM connector and found the circuit open. 

TIPM is currently back ordered so installed a Fuse buddy to pull fused power off the fuse pins and ran a bypass wire down to the connector under the TIPM to get the truck back to the customer while we wait for the TIPM. 

Summary: 

Check all powers and grounds, I chased a rabbit trail with the PCM and wasted hours. Once I found the missing power i had the problem figured out in minutes. 

It is possible to have a PCM that's not all the way powered up, the PCM read key switch status over the bus but wouldn't start because it didn't have the key power on pin 71 C2. 

Don't Ignore Data Pids that point to your problem. 

Don't be afraid of working on Deleted trucks - tampering with emissions is federally illegal and We don't do that, but we have customers that have either done their own work or found a shop to do it and need help with other issues. I got lost down a rabbit hole because I thought it was a software / delete problem. check powers and grounds. 

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Michael Mobile Technician
Utah
Michael
 

Andrew, A late model used TIPM can be installed if you have access to someone with the TIPM restore tool. Cody Gaddie has it in Tucson. … He may be able to reset over the internet. I am not aware of anyone in the Phoenix area that has it yet. -Mike

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Andrew Diagnostician
Arizona
Andrew
 

Mike, I was not aware you could use a late model, is it just a flash update or is there something else to make it work? Could a newer (cheaper more available) TIPM be used with the proper flash? Thank you for your feedback and for sharing your knowledge. - Andrew

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Michael Mobile Technician
Utah
Michael
 

Andrew, Using Witech 2.0 to attempt to adapt a used part will likely fail. The TIPM restore tool is an application that uses a PC and J-2534 device. It resets the TIPM so it can be married to a new host. After it is renewed you can then use OE software to update the part if needed. The best practice is to use the same part number or a superseded number as the replacement. The app does not…

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