02 Dodge Ram 1500 Failed PCM Cause? P0601

PCM's do fail - BUT I find that to be very very rare. I would ask you - 1) will your scanner rear all codes- manufacturer specific P1xxx and above? 2) tell us what codes are present now ALL of them. 3) How does truck run now? 4) any and ALL modifications ANYTHING not DODGE... Answer that and Monday I will plug in the codes at work.

Kev2 The only code that shows now is P0601 internal check sum error. failed pcm. Truck runs ok, but gas mileage is not too good.. 13-14 mpg. If I try to put it in passing gear by flooring it, it goes into gear then drops out and jumps back in. sometimes even on a little more than light acceleration. When this happens, the check engine light goes out, then it comes back on in a few seconds. I tried resetting the PCM through the #23 fuse, key turn procedure.. code went away for two key cycles then came back. As far as I know this truck is stock. I've made no mods and I don't see anything other than stock items. and yes, I have an obd-II scanner that can read all codes.. when I look at the freeze frame, I have 4 or 5 out of 8 systems ready, but the freeze frame shows nothing out of the ordinary other than the systems not being ready.

this is all I have right NOW .... from the manual - a powertrain verifaction test. check out steps esp 11 on The issue with down shifting- has me asking again - your scanner WILL report the P1xxx codes, most DIYer tools will not and the issue should set a code.. As mentioned - erase and follow inst- post results. .................................................................................................................... 1. Inspect the vehicle to ensure that all engine components are properly installed and connected. Reassemble and reconnect components as necessary. 2. If this verification procedure is being performed after a NO TROUBLE CODE repair, perform steps 3 and 4. 3. Check to see if the initial symptom still exists. If there are DTCs or the symptom no longer exists, the repair was successful and testing is complete. 4. If the initial or another symptom exists, the repair is not complete. Check all technical service bulletins or flash updates and return to Symptoms if necessary. 5. If this verification procedure is being performed after a DTC repair, perform steps 6 through 13. 6. Connect the DRBIIIt to the data link connector. With the DRBIIIt, erase DTCs and reset all values. 7. If the PCM was not replaced, skip steps 8 through 10 and continue with the verification. 8. If the PCM was replaced, the correct VIN and mileage must be programmed or a DTC will set in the ABS and Air Bag modules. In addition, if the vehicle is equipped with Sentry Key Immobilizer System (SKIS), Secret Key data must be updated to enable start. 9. For ABS and Air Bag systems: Enter correct VIN and Mileage in PCM. Erase codes in ABS and Air Bag modules. 10. For SKIS theft alarm: Connect DRBIIIt to data link conn. Go to Theft Alarm, SKIM, and Misc. Place SKIM in secured access mode by using the appropriate PIN code for this vehicle. Select Update the Secret Key data. Data will be transferred from SKIM to PCM 11. If equipped with a Transfer Case Position Switch, Perform step 12, otherwise, continue with step 13. 12. With the ignition switch on, place the Transfer Case Shift Lever in each gear position, stopping for 15 seconds in each position. 13. Road test the vehicle. If the test is for an A/C DTC, ensure it is operating during the following test. 14. Drive the vehicle for at least 5 minutes at 64 Km/h (40 mph). Ensure the transmission shifts properly through all gears. At some point stop the vehicle and turn off the engine for at least 10 seconds. 15. With the DRBIIIt, read DTCs. Are any DTCs or symptoms remaining? All Yes ! Check for any related Technical Service Bulletins and/or refer to the appropriate Symptom list (Diagnostic Procedure). No ! Repair is complete. 348

The CarScan-Reader I have reads ALL Manufacturer Specific and Generic codes. There are no other codes other than the P0601. I reset the PCM.. cleared all codes with the scan tool and ran the truck as instructed. Same code came back again.. P0601 .. same issues with Trans dropping out on kickdown. It's like the computer just glitches out.. then comes back. IDK. The truck runs fine, shifts through all gears and O/D as long as I don't put it into passing gear.

what I learned - noone has a definate answer... the CW - first try a reflash- a luxary we hav at shop that not easialy available to you... I am stuck on the relationship - kick dwn and failure... cant get aaway from thinking cause and effect... Hail mary idea- clear code, engine running shake harness to trans - see if a connection issue... forces MIL there are 2 other weird a$$ chrysler issues- 1) your cruise control and horn work? 2) A failed TPS causes weird things to happen. As you see I do NOT like condeming PCMs - always asking WHY... If I get another idea I will add.

that dtc means the pcm is unable to Lets call it learn! It'll need a new one and alot of the reman and cheaper sources will not fix that code!

Thanks for your help. I will try the trans harness idea. IDK.. I think one time I cleared the codes at night, went to bed, and when I woke up and started the truck, the engine light came on. same code. will try anything before replacing though..

Well, I got to work today, cleared the codes and let the truck sit. I went out and started it to run the a/c a little. and sure enough, the check engine light came on.. same code P0601.. guess it's PCM time. Thanks for your help Kev2... I'll let everyone know what happens once I get the new one in. may be awhile though.

Installed Reman. PCM last night. Took it on a test run.. seems to be running great. Drove to work this morning, no codes so far. Punched it, and no problems on kick-down. Only one system left to complete so I can get inspection. Waiting on Evap system to complete its cycle. Will keep everyone posted.

Ok... I replaced the PCM. things seems to be fine now.. except for the returning EVAP code P0441. I found a few loose vacuum lines, but it still throws the code. I'm getting very frustrated with it. The shifting and other issues seems to be non-existent for now. Guess it was a bad PCM for that.

p0441 = PURGE solenoid, located at PDC follow the vac lines - green/yellow evap test cap will help locate- no vacuum, no voltage, stuck closed,

the leak detection pump often causes that dtc as well!