96 3500 auto NO OD
06-19-2015, 01:06 AM
#1
Registered User
Thread Starter
96 3500 auto NO OD
This has been going on a while.... NEW transmission. Began having intermittent OD dropouts, with associate OD switch and trans temp light showing up.
It will run out normally for about 4 miles or so - when the WATER temp comes up to normal operating range, trans temp light comes on, OD switch light comes on (in no particular order) and it either drops out of OD or simply will not shift up into OD. Inline resistor made ZERO difference.
Brought truck back from transmission shop again today. Per their scope: TPS is FINE. Throttle cable a tad sticky but normal readings through range of TPS.
They put in not one, but TWO new temp sensor/governor units. Same symptoms, so it's NOT a faulty unit.
Key on shows a trans temp of near 300 degrees (truck on the rack and COLD). Start engine, trans temp drops to 214 (still COLD, mind you) AND it throws a code for engine overheat as well. OF course no OD when the computer is getting these temp readings....
Is there a way to figure out WTH is fault in wiring to cause this? I'm about ready to drive the darn thing into a bridge abutment....
It will run out normally for about 4 miles or so - when the WATER temp comes up to normal operating range, trans temp light comes on, OD switch light comes on (in no particular order) and it either drops out of OD or simply will not shift up into OD. Inline resistor made ZERO difference.
Brought truck back from transmission shop again today. Per their scope: TPS is FINE. Throttle cable a tad sticky but normal readings through range of TPS.
They put in not one, but TWO new temp sensor/governor units. Same symptoms, so it's NOT a faulty unit.
Key on shows a trans temp of near 300 degrees (truck on the rack and COLD). Start engine, trans temp drops to 214 (still COLD, mind you) AND it throws a code for engine overheat as well. OF course no OD when the computer is getting these temp readings....
Is there a way to figure out WTH is fault in wiring to cause this? I'm about ready to drive the darn thing into a bridge abutment....
06-20-2015, 09:01 PM
#2
Cummins Guru
This might be worth checking
Incorrect new part may have been installed. See note provided. Mil lamp may be on. Transmission may be in limp mode. Diagnostic trouble code may be present in powertrain control module (PCM) memory. When transmission is in limp mode the relay that provides power to the solenoid group is switched off. This is normal and is designed to provide operation in one gear only. Transmission temperature very low (-40 degrees) or high (300+ degrees) when checked with DRB diagnostic tool. Overdrive (4th gear) operation inhibited. Transmission governor pressure sensor / valvebody / transmission assembly may have been replaced recently. The transmission temperature sensor is part of the governor pressure sensor and is not serviced seperately. The trans temp sensor resistance value changed with 2000 model year. If wrong governor pressure sensor / valvebody / transmission assembly is installed the trans temp sensor value will be incorrect. Verify correct part is used. IDENTIFICATION and RESISTANCE VALUES: [A]: 1999 and prior (round connector at sensor) = 1,000 ohms resistance. [B]: 2000 and later (flat connector at sensor) = 2,000 ohms resistance. Resistance values are approximate and should be checked at room temperature. NOTE: "HOT TRANS" on DRB display indicates transmission is warmed up (80 to 240 degrees). Suggest verify the DRB diagnostic tool / Supercard / PCM are flash updated to latest release level.
Incorrect new part may have been installed. See note provided. Mil lamp may be on. Transmission may be in limp mode. Diagnostic trouble code may be present in powertrain control module (PCM) memory. When transmission is in limp mode the relay that provides power to the solenoid group is switched off. This is normal and is designed to provide operation in one gear only. Transmission temperature very low (-40 degrees) or high (300+ degrees) when checked with DRB diagnostic tool. Overdrive (4th gear) operation inhibited. Transmission governor pressure sensor / valvebody / transmission assembly may have been replaced recently. The transmission temperature sensor is part of the governor pressure sensor and is not serviced seperately. The trans temp sensor resistance value changed with 2000 model year. If wrong governor pressure sensor / valvebody / transmission assembly is installed the trans temp sensor value will be incorrect. Verify correct part is used. IDENTIFICATION and RESISTANCE VALUES: [A]: 1999 and prior (round connector at sensor) = 1,000 ohms resistance. [B]: 2000 and later (flat connector at sensor) = 2,000 ohms resistance. Resistance values are approximate and should be checked at room temperature. NOTE: "HOT TRANS" on DRB display indicates transmission is warmed up (80 to 240 degrees). Suggest verify the DRB diagnostic tool / Supercard / PCM are flash updated to latest release level.
06-21-2015, 12:07 PM
#3
Registered User
Thread Starter
My replies and questions interspersed in RED and thank you BigIron very much for taking the time to reply!
So, given all the above, I am likely looking at getting the PCM re-flashed to reset readings? MUST this be done by my local and much disliked, sloppy, overcharging dealer's shop?
This might be worth checking
Incorrect new part may have been installed. See note provided.
NOPE, shop owner is a Dodge guy, he also drives a 2nd Gen and is well aware of some of these parts change nuances. He informed me that our truck is an early build with a later harness.... it's a 96. To make sure he was not getting a bad part (it happens) he changed out twice - still same issue.
Mil lamp may be on.
What is Mil Lamp you are referring to? Only lights showing are the indicator in OD lockout button (when it drops OD) and the trans temp warning light in lower panel.
Diagnostic trouble code may be present in powertrain control module (PCM) memory. So PCM needs to be re-flashed? UGH... dealer. HATE local dealer.
Transmission may be in limp mode.
When transmission is in limp mode the relay that provides power to the solenoid group is switched off. This is normal and is designed to provide operation in one gear only.
Trucks functions flawlessly through three gears. It engages OD normally UNTIL IT REACHES OPERATING TEMPERATURE! Is this then "limp mode"?.
Transmission temperature very low (-40 degrees) or high (300+ degrees) when checked with DRB diagnostic tool.
Trans temp READS high - actual temp is normal operating temp as read with heat gun in multiple spots
Overdrive (4th gear) operation inhibited.
Transmission governor pressure sensor / valvebody / transmission assembly may have been replaced recently. The transmission temperature sensor is part of the governor pressure sensor and is not serviced seperately.
See above re: part replacement
The trans temp sensor resistance value changed with 2000 model year. If wrong governor pressure sensor / valvebody / transmission assembly is installed the trans temp sensor value will be incorrect. Verify correct part is used.
IDENTIFICATION and RESISTANCE VALUES:
[A]: 1999 and prior (round connector at sensor) = 1,000 ohms resistance. [B]: 2000 and later (flat connector at sensor) = 2,000 ohms resistance. Resistance values are approximate and should be checked at room temperature.
NOTE: "HOT TRANS" on DRB display indicates transmission is warmed up (80 to 240 degrees).
Suggest verify the DRB diagnostic tool / Supercard / PCM are flash updated to latest release level.
Incorrect new part may have been installed. See note provided.
NOPE, shop owner is a Dodge guy, he also drives a 2nd Gen and is well aware of some of these parts change nuances. He informed me that our truck is an early build with a later harness.... it's a 96. To make sure he was not getting a bad part (it happens) he changed out twice - still same issue.
Mil lamp may be on.
What is Mil Lamp you are referring to? Only lights showing are the indicator in OD lockout button (when it drops OD) and the trans temp warning light in lower panel.
Diagnostic trouble code may be present in powertrain control module (PCM) memory. So PCM needs to be re-flashed? UGH... dealer. HATE local dealer.
Transmission may be in limp mode.
When transmission is in limp mode the relay that provides power to the solenoid group is switched off. This is normal and is designed to provide operation in one gear only.
Trucks functions flawlessly through three gears. It engages OD normally UNTIL IT REACHES OPERATING TEMPERATURE! Is this then "limp mode"?.
Transmission temperature very low (-40 degrees) or high (300+ degrees) when checked with DRB diagnostic tool.
Trans temp READS high - actual temp is normal operating temp as read with heat gun in multiple spots
Overdrive (4th gear) operation inhibited.
Transmission governor pressure sensor / valvebody / transmission assembly may have been replaced recently. The transmission temperature sensor is part of the governor pressure sensor and is not serviced seperately.
See above re: part replacement
The trans temp sensor resistance value changed with 2000 model year. If wrong governor pressure sensor / valvebody / transmission assembly is installed the trans temp sensor value will be incorrect. Verify correct part is used.
IDENTIFICATION and RESISTANCE VALUES:
[A]: 1999 and prior (round connector at sensor) = 1,000 ohms resistance. [B]: 2000 and later (flat connector at sensor) = 2,000 ohms resistance. Resistance values are approximate and should be checked at room temperature.
NOTE: "HOT TRANS" on DRB display indicates transmission is warmed up (80 to 240 degrees).
Suggest verify the DRB diagnostic tool / Supercard / PCM are flash updated to latest release level.
06-22-2015, 08:06 AM
#4
Administrator
halfpint, no he is just giving you the diagnostics out of the FSM.
I think somehow your wiring is still chuffed up, and the PCM is getting too much voltage back, telling the PCM it is running hot.
If I get a chance, i will look into the FSM to see what values are expected, sorry I haven't had tome to help you yet.......
I think somehow your wiring is still chuffed up, and the PCM is getting too much voltage back, telling the PCM it is running hot.
If I get a chance, i will look into the FSM to see what values are expected, sorry I haven't had tome to help you yet.......
06-30-2015, 01:35 PM
#5
Registered User
Thread Starter
halfpint, no he is just giving you the diagnostics out of the FSM.
I think somehow your wiring is still chuffed up, and the PCM is getting too much voltage back, telling the PCM it is running hot.
If I get a chance, i will look into the FSM to see what values are expected, sorry I haven't had tome to help you yet.......
I think somehow your wiring is still chuffed up, and the PCM is getting too much voltage back, telling the PCM it is running hot.
If I get a chance, i will look into the FSM to see what values are expected, sorry I haven't had tome to help you yet.......
engine reaches operating temps (that's a water temp, right?) kind of makes me thing something is misreading in the computer itself? why else would the shop's scope tell them that there was a code for both trans temp HOT and engine temp HOT?
Can anyone besides a Dodge dealer reflash the computer? If so, how do I find them?
Wits' end here..... still a great truck but only a three speed
07-01-2015, 08:18 AM
#6
Administrator
I wish I could find the ohm readings expected by the PCM, the only thing I find is 1K ohms at room temp, but they don't tell you where they go to read hot. Just for grins, is the resistor still in the wiring up by the PCM? Perhaps remove it?
07-01-2015, 12:14 PM
#7
Registered User
Very interesting, the post by BigIron about the different year sensors having a different resistance range. It sure sounds like a possibility for your problem. I know you trust your technician, but is it possible that someone up the line could have looked the part up wrong that he was given?
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07-06-2015, 01:29 PM
#8
Registered User
Thread Starter
Thanks PatDaly, and TorqueFan too - I am getting to the point of removing that so-carefully soldered in resistor, and then - wire by bloody wire - doing a total reset of ALL the harness coming into the three connectors at the PCM....
yeah, I know, and that's why I am procrastinating.https://www.dieseltruckresource.com/...ew1/madani.gif
Given that the boyz up at DTT had hacked into the harness to install their miserable controller box for their tranny that failed utterly shortly after installation, I really am thinking that there is a good possibility of a wire having been jerked nearly out of it's contact end - which are only squash fit contact, anyhow, and then pressed into the connector socket. They had whacked off one wire (orange) at all of half an inch from the back of the connector block.....
The three big connectors are made in two halves, obviously for original assembly, BUT since they do have a press-fit clip closure, I see no reason I cannot dis-assemble and check this out. If a wire end is stranded at the contact, that WOULD cause less than optimum current flow, or possibly even an intermittent - which answers perfectly to what the truck is doing (or not doing).
What say you wiser CTD folk? Do I dare? My ruined lower back is NOT looking forward to being draped over a fender for a few hours at a time... Need to buy stock in Aleve.
yeah, I know, and that's why I am procrastinating.https://www.dieseltruckresource.com/...ew1/madani.gif
Given that the boyz up at DTT had hacked into the harness to install their miserable controller box for their tranny that failed utterly shortly after installation, I really am thinking that there is a good possibility of a wire having been jerked nearly out of it's contact end - which are only squash fit contact, anyhow, and then pressed into the connector socket. They had whacked off one wire (orange) at all of half an inch from the back of the connector block.....
The three big connectors are made in two halves, obviously for original assembly, BUT since they do have a press-fit clip closure, I see no reason I cannot dis-assemble and check this out. If a wire end is stranded at the contact, that WOULD cause less than optimum current flow, or possibly even an intermittent - which answers perfectly to what the truck is doing (or not doing).
What say you wiser CTD folk? Do I dare? My ruined lower back is NOT looking forward to being draped over a fender for a few hours at a time... Need to buy stock in Aleve.
07-06-2015, 09:45 PM
#9
Registered User
Sounds like a good plan. The vast majority of wiring problems happen where somebody has previously hacked into the wiring, so if it was mine, I'd get rid of that resistor then have a good look at the stuff they've already cut into.
Hope you find it.
Hope you find it.
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