73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Deercreekfarm on December 28, 2019, 08:39:27 PM
-
I have a 1991 Suburban V2500 with the 6.2L diesel. I’ve been rebuilding it. Started with the engine because I had an over heating issue, got that fixed. Now I am focusing on the transmission. Since I’ve had it, it’s never shifted into overdrive. Reverse and gears 1-3 work great just no OD.
I’ve checked fluid level, good. Checked all fuses, good. Checked linkage, good. Cleaned connectors, good and still nothing. So after reading (I know this probably sounds crazy) it said the cruise control being out could restrict the transmission from locking up. I have a tilt column with cruise control which does NOT work. Also I have no reverse lights and when I plugged a code reader into the OBD1 port there’s nothing, no power.
I replaced the brake switch on the column, no change. So I ordered a tilt column with working cruise control from another 1991 suburban. It got here today and I will be installing it tomorrow (weather permitting). I figure even if this isn’t the issue i will have a good working column.
Has anyone heard of this? Is the cruise control not working, no power to OBS1 and reverse lights out related to the OD issue?
Anyone have any suggestions on how to fix any one or all of these issues? I’m thinking I may have to pony up $1200 for a transmission rebuild but want to make sure I get everything working right before dropping big bucks on the transmission.
Thanks in advance for any feedback!
-
So you have no serial data or service engine soon light?
-
Truck runs and drives great just no OD. When I turn the key on the yellow glow plug light and the red water in fuel light come on for a few seconds then goes off and the glow plug light comes back on as the glow plugs cycle. I know my low coolant light came on when I had my overheating issue. And the only other light that I’ve seen is my blue dot light letting me know when my high beams are on.
-
Sure you have a 4L80E in there right?
CHART A-1 NO SERVICE ENGINE SOON/TRANS LIGHT
Circuit Description:
There should always be a steady 'Service Engine Soon" or "Trans" light with the ignition "ON" and engine stopped. Switched battery voltage is supplied to the light bulb. The PCM/TCM will control the light and turn it "ON" by providing a ground path through CKT 419 or CKT 1234.
Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
If the ECM-B fuse is blown, refer to complete wiring circuit.
Using a test light connected to 12 volts, probe each of the system ground circuits to be sure a good ground is present.
Diagnostic Aids:
If the engine runs OK, check:
Faulty light bulb.
CKT 419 open.
Gauges fuse blown. This will result in no brake warning light, oil or generator lights, seat belt reminder, etc.
If the engine cranks but will not run, check:
Continuous battery ECM-B fuse open.
Ignition in-line fuse open.
Battery CKT 440 to PCM/TCM.
Ignition CKT 439 to PCM/TCM open.
Poor connection to PCM/TCM.
-
VileZambonie,
Yes it’s a 4L80E, 1991 was the first year they were produced and they put them in the suburban first. I will pull the instrument cluster out and check the bulbs. All gages work except oil pressure (I installed an after market one mounted under dash) and the speedometer works and is accurate but the mileage and trip meter are not working.
Yeah I’m going to have to track down those fuses and grounds. It was raining all day today so I wasn’t able to get any work done on it. Hopefully we can have a few days straight of sunshine here in n NC and I can’t get this thing figured out. I appreciate the diagrams. Only question I have is in the top left corner of the first diagram it has all the VIN letter codes. My VIN is a J code and I don’t see that on the list so does that mean it doesn’t pertain to my vehicle or am I missing something?
-
I think you started this on another thread, but agree that you need track down the control issues before rebuild.
Sad if you rebuilt and had the same prob.
-
Refer to my last post, not the first link as it does not pertain to Diesel and yes I know 91 was the first year for the 4L80E, I am just making sure it's still in there...A lot can happen in 30 years
-
UPDATE:
Huston we have lift off!!!!!!!!!!!
She’s running in all 4 gears now. I started by changing out the steering column and the cruise control actuator on top of the engine then pulling all the wires and wiping them down and cleaning up the connectors. Changed out the input and out put sensors (no change). Changed out the vehicle speed sensor (no change). Changed out the throttle position sensor and BINGO she’s alive again!
The sensors I pulled off had GM on them so I would assume they were original. I now have the peace of mind that she’s running all new sensors. Two trans shops wanted $1200-$1400 for a rebuild and turns out it was less than $300 worth of sensors to get her up and running again. She needed the new column (bright lights were broken, ignition issues and housing busted apart) so add in the $200 for that but and you could say $500 total. She’s 29 so it was bound to wear out sooner or later.
Thanks for all your help and advice guys!
-
Hate to break it to you DeerCreeker: Still needs a rebuild!
In 20 years! ;D Thanks for the Update, it means alot!
-
Hate to break it to you DeerCreeker: Still needs a rebuild!
In 20 years! ;D Thanks for the Update, it means alot!
Just because of age or wear and tear?
-
Hate to break it to you DeerCreeker: Still needs a rebuild!
In 20 years! ;D Thanks for the Update, it means alot!
Just because of age or wear and tear?
Hahahahaha!!!!!!! I didn’t scroll down all the way. You scared me there for a minute!!! Thanks.