Did the SOHC come with a cam synchronizer?

[2000StreetRod]

which connector?

According to Rock Auto the OHV camshaft position sensor has a 3 pin male connector.

Are you using the OHV engine wiring harness or the SOHC engine wiring harness? If using the OHV engine wiring harness, did you cut off the OHV cmp sensor connector and replace with an SOHC sensor connector?

 

[snoranger]

Its a mix of both harnesses, mostly '01 sport SOHC. I do have it wired for the SOHC CMP.

 

[2000StreetRod]

OBD-I or OBD-II?

Yes, there has been a problem the whole time. The check engine light has been on the entire time (almost 40K miles) with a (IIRC) p0340 code. Nothing I have done has solved the problem. . .

I thought 1995 was OBD-I (EEC-IV). If so, I can't find a 340 code for it.
If its OBD-II: "P0340 Camshaft Position Sensor Circuit Malfunction" would be a reasonable fault. Will the engine start and run with the CMP connector disconnected? Does it make any difference at all? Does the DTC change when the CMP sensor is disconnected?

There were a lot of electrical changes between 1995 and 1996 when the ICM function was incorporated into the PCM. Are you running an ICM with a 1995 PCM or something later?

 

[snoranger]

I thought 1995 was OBD-I (EEC-IV). If so, I can't find a 340 code for it.
If its OBD-II: "P0340 Camshaft Position Sensor Circuit Malfunction" would be a reasonable fault. Will the engine start and run with the CMP connector disconnected? Does it make any difference at all? Does the DTC change when the CMP sensor is disconnected?

There were a lot of electrical changes between 1995 and 1996 when the ICM function was incorporated into the PCM. Are you running an ICM with a 1995 PCM or something later?

Its been quite a while since I checked the code....but your right, it should be a 3 digit code not an OBDII code. Now that I think about it, it might have been a 214-CID circuit failure. (I can scan it tomorrow to be sure.)
Yes, it starts and runs with or without the CMP hooked up.
Yes, the code comes up with or without the CMP hooked up.
Yes, its the same code.
No, it makes absolutely no difference.
Yes I swapped in another CMP i had around, just to be sure.


'95 computer, '95 ICM, mostly '01 harness ( all wires soldered and heat shrank, or is it heat shrinked?), '95 CKP, '01 (also tried '97) CMP wired as per stock '01 wiring according to Ford EVTM, I even have the SPOUT connector and octane adjust shorting bar in the harness.

 

[2000StreetRod]

Confirm DTC

Thanks for the configuration description. Please confirm the DTC.

I have an electronic copy of a 1996 wiring diagram and the 1995 and 1996 wiring diagram in my Haynes manual in addition to my official Ford 2000 wiring diagram book. I don't know why the OHV sensor has 3 pins since I only see 2 connector pins being used on the wiring diagram.

I would like you to measure some voltages. Please disconnect the sensor connector and measure with the engine not running but the ignition on:

Voltage to ground on RED wire connected to PCM Power Relay
Voltage to ground on DK BLU/ORG wire connected to PCM pin 24
Voltage between RED wire and DK BLU/ORG wire

When you wired in the SOHC sensor connector did you wire the RED wire from the PCM Power Relay to the GY/RD wire on the sensor connector and the DK BLU/ORG wire from PCM pin 24 to the DK BLU/ORG wire on the sensor connector?

I have an electronic copy of an old version of Ford's generic vehicle strategy source code. I'll search thru it (over 8,000 pages) to see what the PCM uses to determine timing. It could be the rising edge of the Hall effect pulse, the pulse exceeding a voltage threshold, the falling edge or exceeding a pulse duration.

 

[SoNic67]

The three pin has power/ground and output signal as pulses of 12V generated by an integrated Hall sensor.
The two pin has a magnetic coil that, when passing the metallic flag in front of it, changes it's self-inductance.
You would need an active electronic circuit to make conversion between the two, it doesn't work just by changing connections.
Or just swap the sensor, to match what PCM is expecting.

 

[2000StreetRod]

3 pin connector

My electronic 1996 wiring diagrams are much more complete than what is in my Haynes manual. It agrees with the 3 pin connector photo of the sensor from Rock Auto.

BLK/WHT wire to chassis ground
RED wire to PCM Power Relay
DK BLU/ORG to PCM pin 85 (CAM POS IN) with shield to chassis ground (GRY wire). On your 1995 PCM that would pin 24

So now I need to know how the SOHC sensor is wired in on your vehicle.

 

[2000StreetRod]

active circuit

The three pin has power/ground and output signal as pulses of 12V generated by an integrated Hall sensor.
The two pin has a magnetic coil that, when passing the metallic flag in front of it, changes it's self-inductance.
You would need an active electronic circuit to make conversion between the two, it doesn't work just by changing connections.
Or just swap the sensor, to match what PCM is expecting.

Thanks for the confirmation of the pulse output being 12 volts. I suspected as much. Have you determined that by measurement or by available documentation?

We know that active circuitry is required. Do you know if the 1995 PCM is looking for edge trigger, level trigger, or pulse width trigger?

 

[snoranger]

Here Dale, read this.

http://www.explorerforum.com/forums/showpost.php?p=2098740&postcount=7

Its from here:

http://www.explorerforum.com/forums/showthread.php?t=233415


You're correct about Pin 24.

Currently the CMP on my truck is as follows:
DB/O....Pin 24
GY/R....Nothing (its cut. On the advice of Brett, who did this same swap, I tried +12 volts and ground. not at the same time obviously.)
I didnt think that the SOHC CMP would be able to produce the right signal for the OHV computer, thats why I had the plan to build the custom cam sync.


Confirmed....code 214

 

[SoNic67]

We know that active circuitry is required. Do you know if the 1995 PCM is looking for edge trigger, level trigger, or pulse width trigger?

I would expect edge trigger, due to accuracy needed. Now, is it rising or falling edge... I would say rising, based on the usual hall-sensors on market, but I didn't check. It would be trivial to test if you have a "free" sensor.

Now, I think the FLAG might be different too. The '96 one relies on a magnetized metallic flag to trigger the pulses, but the variable reluctance one doesn't have to have that, just a pice of ferro-magnetic material. I have a 2001 syncronizer at home, so I could check if flag is magnetic. I don't have the sensor, mine is in the engine.
So, just replacing the 96 sensor over the 95 assembly might not work.

 

[snoranger]

I would expect edge trigger, due to accuracy needed. Now, is it rising or falling edge... I would say rising, based on the usual hall-sensors on market, but I didn't check. It would be trivial to test if you have a "free" sensor.

Now, I think the FLAG might be different too. The '96 one relies on a magnetized metallic flag to trigger the pulses, but the variable reluctance one doesn't have to have that, just a pice of ferro-magnetic material. I have a 2001 syncronizer at home, so I could check if flag is magnetic. I don't have the sensor, mine is in the engine.
So, just replacing the 96 sensor over the 95 assembly might not work.

'95 and '96 use the same sensor and flag. (At least my late build '95 does.5/95)
They didnt change over to the VR sensor till '98. The flag is not magnetized on the '95-96. There is a magnet in the sensor and the flag passes between the magnet and the sensor.

Also the flags are different between the early and late cam syncs. The early one uses a half moon and the late one uses a single tooth.

Here is the early style "half moon" flag. (and one that had a little accident.)

And the sensor that goes with it. (and again, one that had an accident.)

This is the "single tooth" flag used on the later VR sensor.

 

[2000StreetRod]

Last night I started looking thru the ignition timing section of the vehicle strategy source code. I did not find anything describing the trigger source for the camshaft position sensor. Next I'll look thru the hardware I/O section.

I found the following on the Megasquirt website:

"A Hall Effect Sensor may be normally “high” or normally “low ”, depending on how it is designed. The normally “high” variety (such as GM crank position sensors) produce a steady voltage (equal to the supply voltage) when the magnetic window is unobstructed. The voltage output drops to near zero volts when a blade enters the magnetic window and blocks the field. The Profile Ignition Pickup (PIP) and Cylinder Identification (CID) Hall sensors found in Ford distributorless ignition systems work in the opposite manner. When the shutter blade blocks the magnetic field, the output signal goes from near zero (low) to maximum voltage (high)."

I'll look up the definitions of PIP and CID in the source code to determine if one of them is the camshaft position sensor.

 

[snoranger]

Last night I started looking thru the ignition timing section of the vehicle strategy source code. I did not find anything describing the trigger source for the camshaft position sensor. Next I'll look thru the hardware I/O section.

I found the following on the Megasquirt website:

"A Hall Effect Sensor may be normally “high” or normally “low ”, depending on how it is designed. The normally “high” variety (such as GM crank position sensors) produce a steady voltage (equal to the supply voltage) when the magnetic window is unobstructed. The voltage output drops to near zero volts when a blade enters the magnetic window and blocks the field. The Profile Ignition Pickup (PIP) and Cylinder Identification (CID) Hall sensors found in Ford distributorless ignition systems work in the opposite manner. When the shutter blade blocks the magnetic field, the output signal goes from near zero (low) to maximum voltage (high)."

I'll look up the definitions of PIP and CID in the source code to determine if one of them is the camshaft position sensor.

Let me save you some time.

PIP is profile ign pick-up... Thats the crank sensor.

CID is Cylinder ID... Thats the cam sensor.

 

[2000StreetRod]

edge triggered

"HIGH SPEED DIGITAL INPUTS (HSI)

Each of the eight 8065 high-speed digital inputs (HSIs) can be configured to capture the state of the input signal after either (1) each transition with a rising-edge or (2) each transition with either edge, rising or falling. The latter is the configuration of each HSI unless otherwise noted below.

All inputs, except HSI-0, are updated at 1ms (nominal) intervals and at all PIP edges. HSI-0 is updated at all PIP up and down edges. Actual values vary with engine operating conditions."

. . .


"HSI-6

FUNCTION: CID1 Cylinder ID #1
REGISTER: CID_HIGH Most recently captured state of input
SWITCHES: HP_CIDSEL CID hardware type select -- determines type
of CID sensor (Hall Effect or VRS)
INPUT: J1-85 Via AICE"

Since J1-85 is the input, then the above source code applies to 1996 and later Explorers. The sofware release date on the listing is March, 1997. However, I suspect the above also applies to 1995.

 

[2000StreetRod]

LM1815 suitable device

After a little internet searching I believe the LM1815 is a suitable device for the VR to Hall converter. It appears to have been incorporated into MegaSquirt systems as well as BMW ABS wheel sensor conversions. I ordered two of them from Digi-Key. The following is from the National Semiconductor LM1815 data sheet:

General Description
The LM1815 is an adaptive sense amplifier and default gating circuit for motor control applications. The sense amplifier provides a one-shot pulse output whose leading edge coincides with the negative-going zero crossing of a ground referenced input signal such as from a variable reluctance
magnetic pick-up coil.
In normal operation, this timing reference signal is processed (delayed) externally and returned to the LM1815. A Logic input is then able to select either the timing reference or the processed signal for transmission to the output driver stage.
The adaptive sense amplifier operates with a positive-going threshold which is derived by peak detecting the incoming signal and dividing this down. Thus the input hysteresis varies with input signal amplitude. This enables the circuit to sense in situations where the high speed noise is greater than the low speed signal amplitude. Minimum input signal is 150mVP-P.

Features
Adaptive hysteresis
Single supply operation
Ground referenced input
True zero crossing timing reference
Operates from 2V to 12V supply voltage
Handles inputs from 100 mVP-P to over 120VP-P with external resistor
CMOS compatible logic

 

[2000StreetRod]

parts received

I have about 10 DIS style plug wires, 3 CKP sensors and pigtails, and a few other things all boxed up for you. I'll throw a cam sync, sensor, and pigtail in the box for you to mess around with (I have a few spares.). . .

Yesterday I received the box of parts. Thanks! I haven't been able to find a 2 pin (blade type) male connector similar to the one on the SOHC CMP sensor. Just for information Rock Auto sells a lot of connectors with pigtails. Anyway, it looks like three pins are needed (power, ground and signal). So you'll have to wire in a connector that I will send you when I get farther along.

 

[snoranger]

Yesterday I received the box of parts. Thanks! I haven't been able to find a 2 pin (blade type) male connector similar to the one on the SOHC CMP sensor. Just for information Rock Auto sells a lot of connectors with pigtails. Anyway, it looks like three pins are needed (power, ground and signal). So you'll have to wire in a connector that I will send you when I get farther along.

I even threw in a length of heat shrink tubing, incase you have to extend any of the pigtails. I bought a 100' roll of it of ebay for $5 shipped, even after my swap, i'm only 15' into it.

How many do you want? Let me know right away, I will order them right now and have them drop shipped to you.


Wiring isnt a problem for me, dont worry.

 

[2000StreetRod]

mating connector

I even threw in a length of heat shrink tubing, incase you have to extend any of the pigtails. I bought a 100' roll of it of ebay for $5 shipped, even after my swap, i'm only 15' into it.

How many do you want? Let me know right away, I will order them right now and have them drop shipped to you.

Wiring isnt a problem for me, dont worry.

You may have misunderstood. In the box you sent you included a connector with pigtails that mates with the SOHC CMP sensor. I was looking for a connector with pigtails identical to what is on the CMP sensor. That way I could build a circuit board with two connectors that could be inserted between the CMP sensor and its mating connector. Since you are essentially not using the CMP sensor at this time (one wire is cut or disconnected) then I can use any pair of mating connectors inline between the CMP sensor pigtails and the main wiring harness.

 

[snoranger]

I understood completely. How many do you need?

 

[2000StreetRod]

Connector requirements

. . .
I understood completely. How many do you need?

I think the scheme shown below is a better approach.

I could send you the converter assembly with connectors on each end and a new mating connector to install. You cut off your existing 2 wire CMP connector with pigtails and install the new 3 wire connector. Then you just plug in the converter assembly and send me the old connector with pigtails for the next converter I build. So what I need is a suitable set of mating 3 wire connectors. If there is a connector like the one on the stock OHV CMP sensor then that would be even simpler.