I had a code 700 when I diagnose my 94 GMC Sierra. That is a transmission control unit problem. What's the best and cheapest way to fix it. can I do it myself?

Asked by Feb 19, 2014 at 01:47 PM about the 1994 GMC Sierra 1500

Question type: Maintenance & Repair

I was going 65 70 on the freeway
When I noticed I smelt burning wires.
the truck then kind of held back
power while my foot was still on the
gas . it does this every now and then
feels like its locking up on me. tell me
what's going on and what can I do?

2 Answers

9,355

Well find the burnt wires first. The '94's have a ECM to run the TBI engine and a separate TCU to control the 4L60e. The TCU is located on the drivers side inner fender. Inspect the wiring. Follow the large harness back to the tranny plug. It may be a good idea to drain your tranny fluid to see what conditon the fluid is in. Also inspect the shift solenoids and wiring on the valve body.

9,355

If the wiring looks good you could try replacing the TCU. They are very cheap at the wreckers. Just make sure it's pulled from a 1/2 ton gas with a 4L60e ('93-94). Larger trucks and the 454ss used the 4L80e and the controller is different.

Your Answer

Add photo

Related Questions

Search GMC Sierra 1500 Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 4,610
#2 John Saffrahn
John Saffrahn
Reputation 3,230
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 2,890
View All

Related Models For Sale

Used Ford F-150
3,210 Great Deals out of 205,087 listings starting at $1,779
Used Dodge Ram 1500
527 Great Deals out of 13,262 listings starting at $1,800
Used GMC Yukon
564 Great Deals out of 16,645 listings starting at $2,500
Used Toyota Tacoma
713 Great Deals out of 32,123 listings starting at $2,000
Used Chevrolet Tahoe
852 Great Deals out of 28,369 listings starting at $1,700
Used Chevrolet Camaro
475 Great Deals out of 39,922 listings starting at $3,499
Used GMC Sierra 2500
189 listings starting at $7,500

Used Cars For Sale

2017 GMC Sierra 1500 For Sale
14 Great Deals out of 30,725 listings starting at $23,800
2016 GMC Sierra 1500 For Sale
59 Great Deals out of 4,847 listings starting at $20,990
2015 GMC Sierra 1500 For Sale
172 Great Deals out of 4,392 listings starting at $16,489
2014 GMC Sierra 1500 For Sale
180 Great Deals out of 4,461 listings starting at $13,000
2013 GMC Sierra 1500 For Sale
113 Great Deals out of 2,537 listings starting at $9,988