Code 225 for the Actron FLM tester. Knock sensor not detected during diagnostic run test. Something to that effect. Timing does fluctuate, and I think this might be why my O2 sensors "supposedly" went out. Just changed them the other day and it runs better, but it still hesitates infrequently and jolts when I'm cruising infrequently. I guess I'm asking if there are any other sensors that might cause a false fault code for the knock sensor, or should I consider it bad and change it? I know other things going bad can cause the O2 sensors to indicate bad, that's what I'm trying to ask here. Also, if this is the case, where exactly is it and how hard is it to get to. Any help is appreciated.
Knock sensor
- Thread starter jjmoriset
- Start date
RE: Knock sensor
According to the 1993 PCED OBD-I Section 6A
EEC-IV Pinpoint Test DG {Knock Sensor(KS)} Procedures:
------------------------
DTC 25/225 indicates that the Knock Sensor (KS) signal to the PCM was not sensed during the Dynamic Response Test in the Key On Engine Running Self-Test.
Possible causes are:
-- Damaged Knock Sensor.
-- Open or short in harness.
-- Damaged Powertrain Control Module (PCM).
DG1 CHECK SENSOR VOLTAGE CYCLING
Key off.
Disconnect Powertrain Control Module (PCM). Inspect for
damaged or pushed out pins, corrosion, loose wires, etc.
Service as necessary.
Install breakout box, connect PCM.
Cycle the key to on.
Read DC voltage between Test Pins 23 and 46 at the breakout
box.
Is DC voltage reading between 2.4 and 2.6 volts?
--------------------------
The voltage referred to is the voltage across the sensor(s). The sensors are wired in parallel. Pin 23 is the KS feed wire Y/R(Yellow w/ Red stripe). Pin 46 is the Signal Return wire GY/R(Gray w/ Red stripe). 2.4 to 2.6 volts is normal.
As indicated a false fault code for the KS could be a bad PCM or PCM/harness connection. I am not sure if the timing fluctuating is a possible source or a possible reaction in this case, but baseline timing is one of the pre-checks prior to pin-point tests on the EEC-IV as the following exerpt:
----------------------------
Remember
To prevent the replacement of good components, be aware that the following non-EEC areas may be at fault:
-Fuel (quality)
-Basic engine
-Spark timing
This Pinpoint Test is intended to diagnose only the following:
-Knock sensor (12A699)
-Harness circuits: KS and SIG RTN
-Powertrain Control Module (PCM) (12A650)
-------------------------
I hope this is some help. I remember an early post from Geno? showing exactly where the knock sensors were. A search should turn it up.
According to the 1993 PCED OBD-I Section 6A
EEC-IV Pinpoint Test DG {Knock Sensor(KS)} Procedures:
------------------------
DTC 25/225 indicates that the Knock Sensor (KS) signal to the PCM was not sensed during the Dynamic Response Test in the Key On Engine Running Self-Test.
Possible causes are:
-- Damaged Knock Sensor.
-- Open or short in harness.
-- Damaged Powertrain Control Module (PCM).
DG1 CHECK SENSOR VOLTAGE CYCLING
Key off.
Disconnect Powertrain Control Module (PCM). Inspect for
damaged or pushed out pins, corrosion, loose wires, etc.
Service as necessary.
Install breakout box, connect PCM.
Cycle the key to on.
Read DC voltage between Test Pins 23 and 46 at the breakout
box.
Is DC voltage reading between 2.4 and 2.6 volts?
--------------------------
The voltage referred to is the voltage across the sensor(s). The sensors are wired in parallel. Pin 23 is the KS feed wire Y/R(Yellow w/ Red stripe). Pin 46 is the Signal Return wire GY/R(Gray w/ Red stripe). 2.4 to 2.6 volts is normal.
As indicated a false fault code for the KS could be a bad PCM or PCM/harness connection. I am not sure if the timing fluctuating is a possible source or a possible reaction in this case, but baseline timing is one of the pre-checks prior to pin-point tests on the EEC-IV as the following exerpt:
----------------------------
Remember
To prevent the replacement of good components, be aware that the following non-EEC areas may be at fault:
-Fuel (quality)
-Basic engine
-Spark timing
This Pinpoint Test is intended to diagnose only the following:
-Knock sensor (12A699)
-Harness circuits: KS and SIG RTN
-Powertrain Control Module (PCM) (12A650)
-------------------------
I hope this is some help. I remember an early post from Geno? showing exactly where the knock sensors were. A search should turn it up.
RE: Knock sensor
now if I only had a breakout box! I might have something like that in the dark recesses of my butt. (LOL) I did ck my PCM connection since I have replaced my performance chip a couple times and the connection looks good. Is there an easier way to ck the sensor itself? I honestly doubt the PCM is at fault. This car has run like a champ since the day I bought it and has shown no signs of a PCM failing. If by some freak chance it were the PCM, what would I be looking at to buy another one? Right now, a KS from AutoZone is only $22 and this code only came up after I replaced the O2 sensors. Maybe Geno can assist on this one(come out, come out wherever you are). Thanks for the input.
now if I only had a breakout box! I might have something like that in the dark recesses of my butt. (LOL) I did ck my PCM connection since I have replaced my performance chip a couple times and the connection looks good. Is there an easier way to ck the sensor itself? I honestly doubt the PCM is at fault. This car has run like a champ since the day I bought it and has shown no signs of a PCM failing. If by some freak chance it were the PCM, what would I be looking at to buy another one? Right now, a KS from AutoZone is only $22 and this code only came up after I replaced the O2 sensors. Maybe Geno can assist on this one(come out, come out wherever you are). Thanks for the input.
RE: Knock sensor
I agree, if the harness connection at the PCM looks good, I would doubt the PCM. One other critical harness connection is the engine harness connection under the hood. About a 2" square connector with a center bolt or nut near the driver's side hood hinge up against the cowl/firewall.
Anyways, I don't know and couldn't find a component test for the knock sensor, but at $22 a pop, if it were me I'd go for it. You'll have way more than that in diagnostic time at a service department. After all, that's why we bought the code tester, wasn't it? IMO I would replace both knock sensors at the same time also.
As far as the breakout box goes, if you can get to the knockout sensor harness plug, you may be able to carefully probe the correct wires at the harness plug with a suitable set of test leads for your DVM(Digital Volt Meter) and my favorite Rotunda Tool P/N 62835108 ...
a paper clip.
I agree, if the harness connection at the PCM looks good, I would doubt the PCM. One other critical harness connection is the engine harness connection under the hood. About a 2" square connector with a center bolt or nut near the driver's side hood hinge up against the cowl/firewall.
Anyways, I don't know and couldn't find a component test for the knock sensor, but at $22 a pop, if it were me I'd go for it. You'll have way more than that in diagnostic time at a service department. After all, that's why we bought the code tester, wasn't it? IMO I would replace both knock sensors at the same time also.
As far as the breakout box goes, if you can get to the knockout sensor harness plug, you may be able to carefully probe the correct wires at the harness plug with a suitable set of test leads for your DVM(Digital Volt Meter) and my favorite Rotunda Tool P/N 62835108 ...
a paper clip.
RE: Knock sensor
so there's 2 knock sensors? Or did you mean O2 sensors? If there are 2 of them, where are they? I went through the Ford Service manual (you know, the $90 book that is a total waste of paper) and there is nothing that references the knock sensor(s) on the motor anywhere. I bet it is applied in the PCM service manual sold seperately (what a scam). So I am still stumped. I even cleared the codes and it came back.
so there's 2 knock sensors? Or did you mean O2 sensors? If there are 2 of them, where are they? I went through the Ford Service manual (you know, the $90 book that is a total waste of paper) and there is nothing that references the knock sensor(s) on the motor anywhere. I bet it is applied in the PCM service manual sold seperately (what a scam). So I am still stumped. I even cleared the codes and it came back.
RE: Knock sensor
THere are two knock sensors. They screw into the top of the block. You ahve to take the intake manifold off to get to them. There is a mini harness that goes to them that plugs in at the rear of the engine at the back of the intake. Autozone sells the correct knock sensors.
THere are two knock sensors. They screw into the top of the block. You ahve to take the intake manifold off to get to them. There is a mini harness that goes to them that plugs in at the rear of the engine at the back of the intake. Autozone sells the correct knock sensors.
RE: Knock sensor
Its actually a super easy job. The only real time consumption is getting to the egr tube.
I wouldnt pay someone, they will kill you in Labor $$$$$$$.
Heres a shot of the location.
http://www.lincolnmotorsport.com/enginebay3.jpg
I hope this helps.
Its actually a super easy job. The only real time consumption is getting to the egr tube.
I wouldnt pay someone, they will kill you in Labor $$$$$$$.
Heres a shot of the location.
http://www.lincolnmotorsport.com/enginebay3.jpg
I hope this helps.
RE: Knock sensor
it is really time consuming, and you will most likely damage the EGR tube. The best way to get it off is to unbolt it off of the back of the manifold. You will have to remove the cowl, alternator, coolant tube, intake, fuel rails, ect, and I reccomend the hood, to get to all that stuff. Best of luck
it is really time consuming, and you will most likely damage the EGR tube. The best way to get it off is to unbolt it off of the back of the manifold. You will have to remove the cowl, alternator, coolant tube, intake, fuel rails, ect, and I reccomend the hood, to get to all that stuff. Best of luck
RE: Knock sensor
Yea I must be slow taking these things apart. But I gotta do what I gotta do without a lift like most people do.
I'll tell you what though Geno... You name a part, any part; and next year at Carlisle we will have a race to see who gets that part on and off in the quickest amount of time. I'll even put 100$ to your 50$ that I can do it quicker with the same exact tools.
But of course you have to show up at carlsile with one of YOUR mark VIII's first.
Yea I must be slow taking these things apart. But I gotta do what I gotta do without a lift like most people do.
I'll tell you what though Geno... You name a part, any part; and next year at Carlisle we will have a race to see who gets that part on and off in the quickest amount of time. I'll even put 100$ to your 50$ that I can do it quicker with the same exact tools.
But of course you have to show up at carlsile with one of YOUR mark VIII's first.
unstoppable
Registered
RE: Knock sensor
I'm in.I've installed more sets than anyone here.But since I actually like both of these guys lets make it for a nice steak dinner and dancing girls afterward.That way you guys wont be butt hurt when I woop you.
And we should have an accuracy judge as well cause Eli tells me Joe works sloppy.LOL
I'm in.I've installed more sets than anyone here.But since I actually like both of these guys lets make it for a nice steak dinner and dancing girls afterward.That way you guys wont be butt hurt when I woop you.
And we should have an accuracy judge as well cause Eli tells me Joe works sloppy.LOL
DOHC MARK VIII
Registered
RE: Knock sensor
Sounds like you may we may need some adult supervision. Utilizing my ID card and AARP discount card I qualify….if you’re going to make me prove it through my maturity… I could be in trouble.
** Bill **
1995 LSC-R'ed w/Recaro's and Cobra R's
Veteran of Carlisle 2000/01/02/03
[a href=//cardomain.com/member_pages/view_page.pl?page_id=258112]For Pic's and Mods click here[/a]
...Learn from the mistakes of others. You can't live long enough to make them all yourself....
Sounds like you may we may need some adult supervision. Utilizing my ID card and AARP discount card I qualify….if you’re going to make me prove it through my maturity… I could be in trouble.
** Bill **
1995 LSC-R'ed w/Recaro's and Cobra R's
Veteran of Carlisle 2000/01/02/03
[a href=//cardomain.com/member_pages/view_page.pl?page_id=258112]For Pic's and Mods click here[/a]
...Learn from the mistakes of others. You can't live long enough to make them all yourself....