FleshThorn

1989 pickup, 5 spd, 22RE. The engine light comes on between 10 and 15 mph and then resets when ignition is turned off. I can putt around all day below this speed and no light. No I haven't tried to have the codes read....yet. I believe I read of a couple having the same issue, but I can not find the thread. Anyone have any insight to the cause ?

yayfortrees

READ THE CODES! THEN LOOK UP THE CODES! That should be able to point you in the right direction.

mattaway

Here's a good little page that lists all the codes and symptoms...

http://www.off-road.com/toyota/tech/codes/index.html

FleshThorn

Codes 41(TPS) and 51(KS). Pulled ECU fuse and went for a drive. Check engine light came back on and this time only Code 52 ( Knock Sensor) showed up. Probably a bad wire or connector.

FleshThorn

Appears that one of the previous owners went to the Bubba school of automotive electronics. Someone has cut the wire going to the knock sensor at some point. The wire "attached" to the sensor is not factory and I never even pulled the connector to look at it. They had the other end of the wire twisted to the shielding wire and wrapped with some electrical tape. It was not even attached to the actual copper wire. I connected it and did a test drive, but the engine light came back on is giving Code 52 still. Looks like I have some de-bubbafication to do.

yayfortrees

"de-bubbafication" LOL

FleshThorn

Spliced and soldered in some shielded cable, but that didn't work. Still wondering why they cut out such a big section of the original wiring to start with.

FleshThorn

I have tried several used knock sensors and still kept getting Code 52. Finally bought and installed a new k/s......still code 52. Going to replace connector. I do have continuity between k/s connector and ECU pin. Can only be three things:
1. Knock sensor (replaced)
2. Wire and connector
3. ECU

I am having to use my 89 as a daily driver since my driveway is frozen and the weather has been so snowy. 15-16 MPG kind of sucks as does the lack of power.

93YotaGuy

I had a similar problem with my truck a while back. I kept getting a code 52 even while replacing the sensor. I finally went through the wiring one day and found out that I had a bad connection from where the previous owner spliced the wire. Make sure that the connection is not flawed.

If you keep running it with the engine throwing a code 52 you'll find that one day it won't start. Lets just hope your not far from home when that happens. I know this from experience. I hope it doesn't happen to you my friend.

FleshThorn

I am curious as to if you had continuity between the k/s connector and ECU pin prior to repairing the bad splice ? I have traced back to where the k/s sensor wire runs into the wiring harness underneath the throttle body. I would think that continuity from one end of the wire to the other would kind of rule out a bad splice somewhere between there and the ECU. I will probably try running a jumper wire straight to the ECU if the new connector doesn't solve the issue.

FleshThorn

My new connector came today. I will be splicing it in later this evening. I have read about shielded wire, but it doesn't appear that my model year used it. A few years ago I helped a neighbor to get his Dishnet working. It had not been hooked up for a while and when you would check the voltage out on the antenna, it was not what it took to operate the dish. We cut of the old coax connector, which appeared fine, and installed a new one. Problem solved ! I am hoping that invisible corrosion is the culprit with my code 52 issue.

FleshThorn

I think I solved my Code 52 ! I was wrong in the above post, an 89 22RE does have a shielded K/S wire. The wire for my K/S came out of the wiring harness up next to the throttle body. I found the shielded wire in the harness down near the starter and clipped it off up as far up as I could reach it. I then spliced and soldered the new connector w/ wire. I then sealed the soldered splice with liquid electrical tape and wrapped some regular electrical tape around it for extra protection. Then I used a wrap of aluminum foil to splice the shield wire followed with several wraps of electrical tape. I have only drove it out the driveway and back, but NO check engine light ! I will be satisfied that it is fixed after i drive home tonight. The savings in gas should pay for the new sensor and connector over the next year.

Edited to add: Check engine light came back on on the way home. Looks like I will be re-wiring from knock sensor to ECU.

FleshThorn

I started a new thread as a result of this one : https://www.yotatech.com/forums/f116...r-hour-210336/

I replaced the knock sensor with a new one plus a new connector. Still Code 52. I ran a jumper using standard automotive wire from the knock sensor out through the fender well and under the door and to the ECU. NO CODE 52 !!! I then tried running the jumper wire through the fire wall and the Code 52 would come back. I figure that since this is unshielded wire it must be picking up some interference when running through the firewall. I ran it back out the fender well and I do not get a Code 52. This is just a temporary fix at best, but I now know how the truck is supposed to run. So, I now know I need to either repair the shielded wire or replace it all together. I do have a question for those who have re-wired the KS to ECU, how is the shield grounded and where ? Where the KS wire runs into the ECU, I do not see any of the shield.

shaeff

I always find a good ground under the dash. Less likely to get corrosion. Could also use the ECU ground.

FleshThorn

Ran coax from ks straight to ECU. Grounded the shield underneath the dashboard to the firewall using a ring connector and a self tapping screw. No Code 52 and it runs like a different truck. Shaeff, reading your knock sensor thread was a great big help. Thanks.

shaeff

Glad to help!

FleshThorn

I have had this rig for almost a year now and it has been throwing a Code 52 and nothing else constantly up until today when I finally got the KS circuit to working. As I was coming home a few minutes ago and thinking how nice it is to not have the Check Engine light on,......... it comes on. A quick check shows a code 25 and 26. I read a couple of threads where others have had the same issue, but I didn't find any solutions. I find it odd that it would throw these two codes the exact same day that I fixed the Code 52.

FleshThorn

Adjusted TPS, new exhaust pipe from manifold back and new Denso O2 sensor. MAF meter tests in spec. New PCV vacuum line and grommet. Still Codes 25 and 26 after driving a while.

4Crawler

iTrader: (3)

Is there vacuum at the fuel pressure regulator?
- http://www.4crawler.com/4x4/CheapTri...ine_Pix/8.html

And have you tested for continuity between the TPS, AFM, O2 sensor and the ECU?
- http://www.4crawler.com/4x4/CheapTri...roubleshooting

FleshThorn

Thanks. Positive for vacuum at fuel pressure regulator. May be a day or so before I can get around to checking continuities.