Help with SRS codes, 2004 taco 2wd

2.4L 5sp, 74k miles(not a typo, yes 74 thousand miles) My SRS lights been on solid (no blink) for 2 years. I finally decided to look into it. Below is a video of the codes with Tc and CG bridged(shorted). After ignition on for over 20 seconds.

Yes I 1st checked all the fuses, with ohm meter.

This video is started before Tc and CG are bridged, so u see it lite solid. Then as Tc and CG are bridged, it goes out for 4 seconds, then starts showing the codes. It cycles 3 times through the codes. Here: https://youtu.be/5lM5NeeDCuY

another video taken the day before. This video started mid way through the codes: https://youtu.be/gaiUZKllk5c

It looks to me like 31, 11, 1, 2, 52 or maybe 31, 111, 2, 52. Since 1, 2 and 111 dont exist, maybe it is 11 and 12.

Either way it does not follow the service manual:

"When 2 or more codes are indicated, the codes will be displayed in numeral order starting from the lowest numbered code" "In the event of a number of trouble codes, indication will start from the smallest numbered code"

Additional from service manual:

"The first blinking output indicates the first digit of a 2–digit DTC. After a 1.5–second pause, the second blinking output will indicate the second digit."

"If there are 2 or more codes, there will be a 2.5–second pause between each code. After all the codes have been output, there will be a 4.0–second pause and they will all be repeated"

of course there is also: "If a code not listed on the chart is displayed, the "airbag sensor assembly" is faulty". Since all 20 of the codes listed in the DIAGNOSTIC TROUBLE CODE CHART list "airbag sensor assembly", I might need to go through all 20 tests. My luck the last test will find the issue. Actually, worse none of them will find it, which means Id need to do it again to be sure. Ahhhhhh.

The DIAGNOSTIC TROUBLE CODE CHART for my taco here: http://www.markofshame.com/fsm/03_Tacoma/Repair_Manual/03tacoma/di/rs/dtcc.pdf

Ideas/suggestions?

Tks, pa

 

That thing doesn’t have OBD-2?!?!?

 

I get 31, 11, 12, and 52?

 

Tc and CG bridged(shorted) in OBD/OBD2

 

I also see

“If a code not listed on the chart is displayed, the airbag sensor assembly is faulty.”

Since code #31 is not listed, and you have a code for 52 (airbag sensor), I’d assume it the sensor assembly ?

B0108/52 (DI–629)

S Short in P squib circuit (to B+)
S Front passenger airbag assembly (squib) S Passenger airbag manual on–off switch
S Airbag sensor assembly
S Wire harness

 

Giving a bunch of codes, indeed.

I at least see 31 and 52. Maybe 11 and 12 too

Code 31 means the airbag ECU is malfunctioning and since it is the brain, if it is bad, it can pop any code or even random non-existent error codes

First of all, the SRS system is very voltage sensitive and the slightest battery or ground issue can trigger codes and errors, so:

How is the battery? Been having battery issues over the last year?
Have you checked for a bad battery ground?
Was the battery replaced? If yes, were the keys in the ignition on ACC or ON position? This can trigger random codes and errors that will need to be erased
Then have you tried having the codes cleared?

yes, they have OBD2 but you pull the airbag codes either through shorting pins in the DIAGNOSIS port in the engine bay or with a SRS-capable scan tool hooked on the ODB2 port

 

which dont comply with "When 2 or more codes are indicated, the codes will be displayed in numeral order starting from the lowest numbered code" "In the event of a number of trouble codes, indication will start from the smallest numbered code"

Code 31 says if there are other error codes, to trouble shoot them 1st. The troubleshooting for 52 is WAY involved. Hopefully, some home Mechanics have better easier fixes.

 

I don’t have the FSM for that year.
There very well may be an easier way to Troubleshoot it.
Following DTC Flow charts can be very time consuming.
I’ve been know to start at “what I suspect” first.
But I haven’t done much SRS stuff. So there may be no “easy” short cuts.

Hopefully some one with experience can help you out.

 

Battery replaced 4 months ago. Grounds look good. Keys not in when replaced. do ppl, actually do that?

I haven't cleared the codes. The codes listed above are current. Need use different procedure to read history.

ECU same as Airbag sensor assembly?

Tc and CG in DLC3 under dash supplies error OBD/2 codes.

 

Here http://www.markofshame.com/fsm/03_Tacoma/

 

Yeah some people forget the keys in the ignition, thinking it is a OFF when it isn't and the SRS system isn't too happy when this happens. Even if the battery have been replaced, check the voltage and charging system to rule it out

Try clearing the codes and see if they come back
And no, engine ECU and airbag ECU are two different electronic modules

 

Out of curiosity, have you tried Turn the Passenger Air Bag OFF (or ON)
Clearing the codes and then seeing if it comes back on?

The Common tho has between all 3 codes are;
Airbag Sensor Assembly and -Wiring Harness

Here how I’d go about diagnosing it.

1. Try the Passenger Air Bag On/Off Switch.
See what or if anything changes with it On vs Off.
If nothing changes, go to step 2.
(Or maybe test the actual switch, depending on the difficulty of accessing)

2. Follow the steps, to diagnose the Airbag Sensor Assembly.
(IIRC, it was simply unplug it and look for the light to go off?)

3. Move on to the wiring harness Tests.
It looks like the sensors is in the front of the truck?
I’d start with the passenger one. Inspect the wiring then do the test.

My suspicion is it either a wiring harness issue, or the sensor assembly.

 

according to service manual unit resets itself if and when its fixed, no need to clear codes. I take that to mean that clearing codes now wont help, but its pretty easy to do, so maybe I try that.

Im aware that car has two different ECU units, but im still not sure about the "Airbag sensor assembly". Is that the SRS ECU?

Passenger off switch appears to work. It lights up "off" when off and turns off the "off" light when on, and neither effects the SRS dash light. I thought of testing it, but the service manual protocol for that is very involved. Not simply remove and ck with ohm meter.

Does anyone kno why that online service manual the page links work fine, but once manual is downloaded they dont work, which makes using it VERY difficult. This site even has a dnldable version, but the links still dont work. http://web.archive.org/web/20080731033603/http://www.ncttora.com/fsm/

 

ive tried to clear the history 7 times following here http://www.markofshame.com/fsm/03_T.../preche.pdf#[0,{"name":"XYZ"},null,null,null]

they wont clear.

 

Wow, that is a process to just clear the codes.
You are using 2 different wires, correct?
You don’t jump from on pin to the other.
I don’t know, if I were really serious about fixing this ABS issue, I’d consider getting a scan tool capable of reading ABS/SRS. I believe you can find them for under $100 now. Maybe less on Amazon?


5. DTC CLEARANCE (Using service wire)
(a) Connect the 2 service wires to terminals Tc and AB of
check connector.

(b) Turn the ignition switch to ON and wait for approx. 6 seconds.

(c) Starting with the Tc terminal, ground alternately terminal Tc and terminal AB twice each in cycles of 1.0 second. Make sure that the terminals are grounded. Ensure the terminal Tc remain grounded.

HINT:
When alternately grounding terminals Tc and AB, release ground from one terminal and immediately ground the other terminal within an interval of 0.2 seconds.
If DTCs are not cleared, repeat the above procedure until the codes are cleared.

 

anyway history should not effect current operation. Both front sensors 822k ohms.

 

both Pretensioners 3 to 4 ohms

 

what does this mean? See page 2. It talks about the pass air bag and the sensor, but illustrates a connector between the on off switch and the pass air bag. Here http://www.markofshame.com/fsm/03_T...ib01085.pdf#[0,{"name":"XYZ"},null,null,null]

 

Yes, airbag sensor assembly refers to the SRS computer (ECU)

When downloaded, at the root of the FSM folder, if you open the "index.htm" file, the FSM will open as table of contents in your browser, allowing you to click and consult the pages individually. Just press back when you want to go back to the table of contents

I've tried hundreds of times clearing the codes with this method and it never worked. Ended up using a scan tool instead

 

done there, been that. those page labels in the index are not labeled with the page numbers linked in pages. so same problem. Try it. In that index scowl down and click on
Diagnostics##Supplemental Restraint System##cialways.pdf

then go down to page two and click on (See step 1 on page DI–675) and see where it takes you. Nowhere.