Codes P0785, P0740. P0785. P1860, P0420

Ladybug263 · 08-21-2007, 05:17 AM

Had my 98 Chevy 1500 inspected. It failed miserably!! Had it scanned at my local AutoZone and came up with codes P0753 Shift solenoid failure, P0740 TCC solenoid failure, P0785 transmission 3-2 shift solenoid, P1860 TCC PUM solenoid circuit failure and P0420Catalyst efficiency low-bank 1.

Can anyone explain what all of this means?? Is it the whole transmission or just the spolenoid/circuit to the transmission?? Truck has 160,000 miles on it. Is it worth it to fix it????

Sounds like it might be costly.

I appreciate any input!!!!!!!!

mrjohnwayne · 08-21-2007, 07:54 AM

Does the truck shift or act wierd while driving. With those codes it would seem the thing would shift like crazy. If it is just the solenoids it should not be too terribly expensive to repair.

Im not sure what the Po420 code is. Sounds like an 02 sensor there.

75K30 · 08-21-2007, 08:07 AM

Welcome to the site.
With all of those transmission symptoms and codes. This may indicate a failure in the harness that the transmission communicates through. Might have it checked to make sure it is connected well.
Second thought is that the transmission has a bunch of miles and could be close to the end of its life. If poor shifting and performance is occuring you may be in for a decent repair. All those solenoids are replaceable and can be purchased for around $20.00 each, but no guarantee that this will completely fix the problems.
Finally the catalyst problem would indicate that the left cat converter is no longer doing its job, and has lost its ability to convert gases and probably not emissions compliant. Replacing this will most likely mean that you should change the other too. These will have the same amount of miles and use, so it will be safe to assume that the other is tired and will also fail soon.

Ladybug263 · 08-21-2007, 09:18 AM

At times it's very sluggish ( I assume that would be to do with my emissions problem) I haven't had any problems feeling any unusual shifting. Was surprised when the troubleshooting came up with something transmission related.

75K30 · 08-21-2007, 09:44 AM

That P0740 code woould indicate that the converter is not locking up. Does the overdrve work?
Not familiar with NY inspections, what do they include, and what are they inspecting? Most of those codes can be reset, and may not appear at all. Even the converter can be worked around if it has not fallen apart. In fact the catylist efficiency diagnostic is only run once in a while. It is not a continuous test.

Ladybug263 · 08-21-2007, 10:41 AM

NY has safety and emissions. Passed the safety but failed the emissions. Only one emissions code came up for the catalyst system. I'm thinking I should replace the oxygen sensor & catalytic converter to pass the inspection and then have the transmission solenoids and torque converter checked. Overdrive does work.

75K30 · 08-21-2007, 10:46 AM

If the trans is working, there is a possibilty that there is simply a pressure problem. Since the trans has nothing to do with the emissions, I would make the repairs to get it to pass, and wait untill the trans fails entirely. You could be chasing your tail trying to fix a bunch of stuff.
Did they do a tailpipe sniffer test?

Ladybug263 · 08-21-2007, 10:59 AM

No tailpipe sniffer test. Just hooks up to the techs computer and scanned. Is the oxygen sensor & catalytic converter something I can change myself?? (I'm new at DIY repair!) I'm sure the tranny stuff is too difficult!

bradrhale · 08-21-2007, 11:04 AM

you have different laws up there. anything older than 3 gets the sniffer up the tailpipe.

75K30 · 08-21-2007, 12:18 PM

The solenoids are actually easier than the converter(S). Those rusty old bolts usually break off. They have been heated to over 600 deg F and cooled so many times they become brittle, and they have developed a bunch of corossion. Same thing applies to the 02 sensors.
The test they are performing is a simple OBDII scan. They are simply just checking to see if the system has any failures.
You know I would try disconnecting the battery for a few minutes and take it down to the place that helped you read the codes. I would do this to verify the codes and see if any have changed or disappeared, before I started changing stuff.
How long has the check engine light been on?

08-21-2007, 05:17 AM	#1
Ladybug263 Full Member Join Date: Jul 2007 Location: Upstate New York Posts: 22	Codes P0785, P0740. P0785. P1860, P0420 Had my 98 Chevy 1500 inspected. It failed miserably!! Had it scanned at my local AutoZone and came up with codes P0753 Shift solenoid failure, P0740 TCC solenoid failure, P0785 transmission 3-2 shift solenoid, P1860 TCC PUM solenoid circuit failure and P0420Catalyst efficiency low-bank 1. Can anyone explain what all of this means?? Is it the whole transmission or just the spolenoid/circuit to the transmission?? Truck has 160,000 miles on it. Is it worth it to fix it???? Sounds like it might be costly. I appreciate any input!!!!!!!!

08-21-2007, 07:54 AM	#2
mrjohnwayne Senior Moderator Join Date: Apr 2005 Location: Texas Posts: 3,792	Does the truck shift or act wierd while driving. With those codes it would seem the thing would shift like crazy. If it is just the solenoids it should not be too terribly expensive to repair. Im not sure what the Po420 code is. Sounds like an 02 sensor there. __________________ John Wayne 2000 F-350 7.3L Powerstroke 4x4

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08-21-2007, 08:07 AM	#3
75K30 Senior Member Join Date: Jul 2006 Posts: 3,312	Welcome to the site. With all of those transmission symptoms and codes. This may indicate a failure in the harness that the transmission communicates through. Might have it checked to make sure it is connected well. Second thought is that the transmission has a bunch of miles and could be close to the end of its life. If poor shifting and performance is occuring you may be in for a decent repair. All those solenoids are replaceable and can be purchased for around $20.00 each, but no guarantee that this will completely fix the problems. Finally the catalyst problem would indicate that the left cat converter is no longer doing its job, and has lost its ability to convert gases and probably not emissions compliant. Replacing this will most likely mean that you should change the other too. These will have the same amount of miles and use, so it will be safe to assume that the other is tired and will also fail soon.

08-21-2007, 09:18 AM	#4
Ladybug263 Full Member Join Date: Jul 2007 Location: Upstate New York Posts: 22	At times it's very sluggish ( I assume that would be to do with my emissions problem) I haven't had any problems feeling any unusual shifting. Was surprised when the troubleshooting came up with something transmission related.

08-21-2007, 09:44 AM	#5
75K30 Senior Member Join Date: Jul 2006 Posts: 3,312	That P0740 code woould indicate that the converter is not locking up. Does the overdrve work? Not familiar with NY inspections, what do they include, and what are they inspecting? Most of those codes can be reset, and may not appear at all. Even the converter can be worked around if it has not fallen apart. In fact the catylist efficiency diagnostic is only run once in a while. It is not a continuous test.

08-21-2007, 10:41 AM	#6
Ladybug263 Full Member Join Date: Jul 2007 Location: Upstate New York Posts: 22	NY has safety and emissions. Passed the safety but failed the emissions. Only one emissions code came up for the catalyst system. I'm thinking I should replace the oxygen sensor & catalytic converter to pass the inspection and then have the transmission solenoids and torque converter checked. Overdrive does work.

08-21-2007, 10:46 AM	#7
75K30 Senior Member Join Date: Jul 2006 Posts: 3,312	If the trans is working, there is a possibilty that there is simply a pressure problem. Since the trans has nothing to do with the emissions, I would make the repairs to get it to pass, and wait untill the trans fails entirely. You could be chasing your tail trying to fix a bunch of stuff. Did they do a tailpipe sniffer test?

08-21-2007, 10:59 AM	#8
Ladybug263 Full Member Join Date: Jul 2007 Location: Upstate New York Posts: 22	No tailpipe sniffer test. Just hooks up to the techs computer and scanned. Is the oxygen sensor & catalytic converter something I can change myself?? (I'm new at DIY repair!) I'm sure the tranny stuff is too difficult!

08-21-2007, 11:04 AM	#9
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 9,558	you have different laws up there. anything older than 3 gets the sniffer up the tailpipe.

08-21-2007, 12:18 PM	#10
75K30 Senior Member Join Date: Jul 2006 Posts: 3,312	The solenoids are actually easier than the converter(S). Those rusty old bolts usually break off. They have been heated to over 600 deg F and cooled so many times they become brittle, and they have developed a bunch of corossion. Same thing applies to the 02 sensors. The test they are performing is a simple OBDII scan. They are simply just checking to see if the system has any failures. You know I would try disconnecting the battery for a few minutes and take it down to the place that helped you read the codes. I would do this to verify the codes and see if any have changed or disappeared, before I started changing stuff. How long has the check engine light been on?