Seat belt repair

[Doctor J]

Man, the stuff goes… right or the first New Year’s resolution.

I will always remember the thread posted by one of the desperate forum users about the seat belt problem in generation two Camry. Yesterday, December 31 after replacing the floor carpet in my wagon with one in the near mint condition, I have discovered that the passenger side automatic shoulder belt is not retracting when door is open. Below I would try to explain how I located and fixed the problem, and I would try to stay away from ASE related terms if possible, so more ordinary do-it-yourselves would be able to use the electrical troubleshooting skills.
In order to better understand how the input signal circuit to the passenger side belt works, let’s imagine the belt anchor located in the middle of its travel. You could bring belt there by spinning the wheel on the belt motor while ignition key is off. If you turn the ignition on, and the door is open, the anchor will move toward windshield. If the door is closed the belt will move toward seat. The three wires, single pole double throw switch, located in the door latch connects to the ground either one of two signal circuits that are going from the seat belt computer. Such design is done in order to make door position signal fool proof. In addition, the belt travel limit switches, located at each end point of the belt track are closed (having continuity) when the belt is anywhere between its end stops. The belt motor is connected to the seat belt computer via two wires and isolated from the ground. Therefore, if motor runs even in one direction only, it is not at fault.
So in order to find out why the belt was not moving toward the windshield, I pulled out the pillar inner trim (the upper piece is brittle ABS, the lower one is more flexible polypropylene), and exposed the four wire L connector to the limit switches. In addition, I pried out the small cover under the parking brake lever to expose computer connector and separated the wire plug from it. Then, I opened the print out of Gen 2 electrical wiring diagram on page 115 to verify wire color size and location (my car is 87, and the manual is for 91, but all colors and wire sizes were the same).
Next, I unplugged the limit switches side from 4-wire L connector (2mm flat screwdriver is necessary to unlock such small connector tab). After that I back probed the terminal 1 of purple/black wire (harness side) with one probe of my ohmmeter, touched the good ground with another probe and pushed the door open. The needle jumped to zero, indicating that door latch switch circuit is good.
Then I placed the meter probes on the ends of light green/yellow wire (terminal 12 of computer plug and terminal 2 of L connector), and the meter indicated open circuit. So I removed the front passenger seat and lifted the carpet to expose R1 connector (also shown on page 38, upper figure). Close inspection revealed that the green/yellow wire end was pulled out of the crimp, resulting in open circuit. The damage was made a while ago, but become apparent only after I moved the harness while replacing carpet. Once I repaired connector and plugged everything back, the belt immediately moved toward the windshield (the door was open). As you noted, I skipped the step of checking the pillar end belt limit switch, because repair of R connector fixed the problem.
In closing statement I need to mention that on the cars build starting around 83-85 the increase of low power electrical circuits forced the car makers to use the wires of 20 gage size and subminiature connectors that are very prone to damage by careless handling. I hope that the above repair experience will help the car owners to fix the automatic shoulder belt malfunctions with better success.

[timebuilder]

Nice job.

Maybe you should rename the post "seat belt repair" or something like it so folks can find it using the search function?

[HomeGrown]

This is an exellent technical article, thanks Doc!

[IvanHoe]

This should be stickied!

[HomeGrown]

Originally Posted by IvanHoe

This should be stickied!

+1

[Carlman(90 CS)]

Nice new sticky Dr J

I have read countless forum posts on TN and other Toyota forum sites that include problems with the automatic belt. Over here in OZ we dont have the A-Belts so we are all good

[Doctor J]

I wish I would stick it earlier,
Thanks Dana_15

[metrodriver]

After I bought my '89 the seat belts would stay forward whenever I had used reverse, and some fuse had blown. After a long search it turned out that the wire bundle attached to the left trunk lid hinge got caught in the hinge, cutting wires (in my case the back-up light wire). I have since seen more cars have the same problem.

[pschultz]

OK. I understand all this, but how do I take the door panel off to get to these seat belt switches?

[jedidivemaster]

Another Seatbelt Question:
I’ve read every seat belt question and solution I can find, so far no luck. I just bought a ’91 Camry DX with a few “character flaws”, one of which is… the passenger belt slider does not move when I open the door (the driver’s side works fine). I suspect that the problem is with the control module because it was sticky, like someone has spilled a few drinks in the center console. How do I check it?

I’ve eliminated every other possibility that I can think of. I don’t have a good wiring schematic for this system or for my fuse panels, despite having bought a new Chilton’s repair manual for the car, so I don’t really know which fuse or breaker affects which system.

The belt motor and gears work. I hot-wired them to get the belt in the forward position.

[jalauer]

Carefully cut open the rubber boot between the door and front fender because I bet one of your wires is cracked. This is what happened to my '91 Camary and with a new wire splice the shoulder strap is working again.

[DAVIS3903]

Ok I have a 1990 camry and i am not sure if the retractors are working ( as in when you need them to during a hard break before you poop in your pants).
i need to know a way to test them or do i need to replace the mechanism. This is a car i got for the daughter as her first ride. just 15. i have been catching up on overlooked maintanince issues. and this one is top on the list.
bd

[Doctor J]

The retractor is not moving the belt in its guide toward the windshield, it just lifts the latch inside the belt spool.

[wmcot]

On our '89 Camry the passenger belt was stuck forward and the dealer wanted $800+ to fix the "control module." I told them, "No thanks" and brought it home. I pulled up the console to look at the control module and it was sticky so I cleaned it up - no change. I got out my Volt meter (I'm an electronic tech) and started checking things out.

The switches on the driver's side belt were operating normally, but the passenger side belt was showing funny readings. I pulled the interior panel off behind the passenger door so I could look at the seat belt track and found that the rear switch was stuck down (ON) with a bunch of grease and dirt. A bit of WD-40 and cleaning and it's worked ever since!

There are end-of-travel switches at the front and the rear of each belt track. If these stick or go bad, they will mess up the automatic belts.

[Sailor90]

Hi,

First time poster here. I am considering buying a used '91 Camry. The driver's side automatic seat belt is stuck forward. From reading this thread, I understand that can be a relatively easy fix. However, the belt itself is also missing a buckle, like it was just torn or cut off.

I am considering bypassing the whole automatic seat belt thing altogether, and just buying a universal traditional 3 point seat belt. This is the product I'm looking at. It says it's for the Camry, but if you look around at the reviews and similar products for other cars, you can tell it's just a universal thing.

http://www.autopartswarehouse.com/de...eNumber=4#desc

My question, since I don't have the car handy to look at, is whether the pillar by the driver's door will be able to accommodate the mounting of this product. Because the Camry has an automatic seat belt, it doesn't normally have anything bolted there, so that's why I'm wondering if it is set up properly for it.

I appreciate any input.

Thanks,
Louis