Can Crankshaft Sensor be tested?
 

I'm currently in a "No Start" situation w/a '93 Ranger 2.3L after changing the timing belt. It was first giving me a DTC code of "222" after the belt change, which I "think" was resolved with the replacement of the Ignition Diagnostic Module (ICM). I believe this is so because my Scanner allowed me to erase the code after the ICM was replaced, whereas I could not erase the code prior.

(If you care to read the whole dilema, it was originally in this thread:Thread 217463

Anyway, now I do not get any KOEO (Key On Engine Off) codes, just the "111" system OK, but it doesn't start any longer, so don't know if any KOER (key on engine running) codes are present.

After testing everything under the sun (except tests that required a breakout box) I'm at a complete loss, Again! ALL tests from primary/secondary Ohm resistance tests of the coil packs to ensuring continuity of all wires going between the coils and ICM to confirming B+ power signals being everywhere they should to etc, etc... all check out "OK"

From other info I've stumbled across (probably from "Ken00" and/or "Rockledge") the only other thing I can think of is the Crankshaft Position Sensor...is there a way to test it? Ford wants $350 for this item, so would hate to guess at this!

Ken00 and Rockledge: You guys still out there? Anyone got any ideas?

Thanks...have a great Holiday Weekend (I'll be under the Ranger!)

I don't think the crank sensor will keep the engine from running. If it is inop, the pcm defaults to a standard setting to keep things running. Are you getting any spark at the plugs? The engine turns over OK? Are you sure the timing belt was installed correctly? Just a few thoughts. Start with the basics. Make sure you have fuel, spark, air, and compression. Keep us posted, and don't buy the sensor quite yet. Start with a compression check. If the belt is correctly installed, the compression will be good.

If I'm not mistaken, the tachometer also takes it's signal directly from the crank sensor. When you are cranking it, does the tach registering any rpms at all?

I think a crank position sensor failure can cause a no-start condition. I've heard of it preventing starts on the Ford DIS/EDIS system.

A bad crank sensor will cause a NO START condition.

Can't answer all the questions just yet, but the ones I can:

Engine does turn over fine, timing belt was definitely installed correctly (I've more than triple-checked this), I know fuel is getting to the injectors (the fuel rail is definitely under pressure), but can't be certain the injectors are getting their signal to spray. I don't have a tach in my truck (which I think is odd for any vehicle w/ a manual tranny!)...will I still have this tach wire going to the PCM? If so, can I backprobe it to see if it's getting a signal from the Crank sensor? Which wire would it be?

I'll be back later to respond to the unanswered Q's: spark, compression and hopefully, injector status. A friend has a "dummy injector" that lights up when receiving a signal, but he's a die hard Chevy guy. If I can locate him, do Chevy & Ford injectors have the same connections?

Thanks so much for your input...I'll post again later this afternoon/evening.

Thanks for the info Bob. I wasn't positive about this. Isn't the sensor a permanent magnet that senses flux change? If so, I would suspect wiring.

I've heard of 2 types of CPS's used. One type is a coil of wire, and a voltage is induced into it from a localized magnet on the crankshaft damper. The second type is a
"HALL EFFECT" device, which is a semiconductor magnetic detector.

hreed, I believe you you may have been thinking about the "Failure Mode Effects Management" system, which is a "default system" similar to what you described.

Regarding the 2.3L DIS system (my '94 SHO has the DIS system and works similarly):

"If the CID circuit fails, the ICM will randomly select one of the two coils to fire. If hard starting results, turning the key off and then cranking again will result in another "guess." Several attempts may be needed until the proper coil is selected, allowing the vehicle to be started and driven until repairs can be made. The Failure Mode Effects Management (FMEM) system will keep the vehicle driveable in the event of PCM system or ignition failures that would otherwise prevent spark angle or dwell commands. The PCM opens the SPOUT line and the PCM fires the coils directly from the PIP output. This results in a fixed spark angle of 10 degrees and fixed dwell...If the ICM does not receive the SPOUT input, it will automatically turn the ignition coils on and off using the PIP signal...

So there is in fact a "failure mode", but it's used for a bad CID signal (camshaft position sensor) and/or bad a SPOUT signal , but not for a bad crankhaft positon (PIP) signal, which is in fact itself the "fallback" sensor signal used during this safety mode.

:-tap

Maybe you could get a CPS cheap at a junkyard.

After ckanking it a bit are the plugs wet with gas, this would indicate the injectors are firing, you can also get a noid light at the parts store to test for the signal.

Well, I "thought" I'd have all of your questions answered, but unfortunately, just a few more:

I am NOT getting spark at any plug and I'm pretty confident that the injectors are not spraying, as there is no sign of fuel on the plugs after cranking. I was not able to locate a "noid" light, but there's still a few places I can try. I would like to be 100% certain the injectors aren't firing.

As for the compression testing, I am unable to locate the 14mm extension that is needed to thread in the hose, but believe a friend should have one.

One other thing I did check was that I am getting B+ (actually 11.5V) at the ICM pin #1 and that there is continuity from all the coil harnesses wires to the ICM (the r/lg and all the tan wires)

I'll hopefully have more info tomorrow.

Thanks SO much for the replies!

Located a "noid" light and suspicions were correct...NO signal to the injectors.

Also, per some pinpoint tests "Rockledge" supplied me with (Thanks!), I'm NOT getting a high/low voltage reading from ICM pins 3 or 4 (PIP). Per the procedure, I should get readings dropping below 2V then jumping above 8V while cranking. For both pins, I'm getting readings consistantly above 8V.

The ICM is getting B+ Voltage.

Per the pinpoint, it's looking like a bad ICM, but that's something I already replaced. I guess I'll keep on testing (most require a breakout box, but I believe I can even do some of those w/o one).

I too am looking at a '93 2.3L with some odd ignition problem. I want to inspect the crankshaft sensor and the wires going to it. My initial problem vaporized the "Ignition ground" pin on the ICM. Now it barely runs.

Rockledge,

One thing to be careful about is that some Ford vehicles with DIS use a camshaft position and crankshaft sensor, while others only have a crank sensor. Case in point, my brother's 95 SHO has both, but my 95 4.0L Ranger has only a crank sensor that uses a "missing" tooth scheme on the crank tone wheel to determine camshaft position.

I agree with Bob Ayers... no crank signal = no start. If you have a separate cam sensor and lose this signal, you can end up with rough start conditions and no tach condition. (Tach, at least for SHO, comes off of cam sensor/ignition module). The rough start is because the engine controller/ignition module are "hunting" for the cam position.

Hey Partsisparts, welcome to FTE!

You and your brother have good taste in vehicles. 8D

Your Ranger's 4.0L ignition is actually an EDIS system, which is a little bit different (not much) than the DIS system. As you point out, the DIS system takes its inputs from BOTH the crankshaft position sensor (PIP) and the cylinder identification sensor (CID) and sends both signals to the PCM for processing vis a vis the DIS module. These are both “hall effect” sensors using the vane-type design. The crankshaft positon sensor generates the PIP signal from its location on the crank (duh). On the OHV engine designs, the CID sensor (a/k/a camshaft position sensor) is positioned on a synchronized shaft that is located in the engine-block where the distributor used to reside. On a DOHC engine like the SHO, the cam sensor assembly is located at the end of the rear exhaust cam and spins off of that.

EDIS, on the other hand, uses a SINGLE input from the crank position sensor, but it's a more complex sensor in this system (variable reluctance, using the "missing tooth" design) which generates a more complex signal, providing for a bit more accurate spark timing, especially during acceleration. The camshaft position sensor remains on EDIS-equipped vehicles, put it is used only for fuel injection timing and does not affect spark timing.

:-X22

dr76,

After looking through what you've written, can you provide some background info regarding the timing belt change? What, if any, symptoms were you having before the belt change? Did you have any codes/check engine light before the belt change? After you changed the belt and had it running (with the original ICM), exactly what was happening? Ran fine cold, rough hot starts? Codes?

As for checking the crank sensor, let me do some digging, as I believe there's some simple checks you can do to get about 90% certainty of a good/bad crank sensor. I believe it's as simple as disconnecting the wiring to the sensor, applying +12V (via alligator clips) to one terminal of the sensor, and reading the other terminal with a voltmeter. Then, you rotate the crank with a breaker bar, looking for movement of the voltmeter reading. (After all, this is what's essentially happening when your truck's running, just at a high rate of speed.) I just need to verify the type of sensor you have and the electrical connections to it. (I believe your sensor may have three wires, due to the information below (crank sensor is both PIP and CID).

In any event, here's some info for the 94 2.3L Rangers. I don't think there is a difference between 93 and 94, but I'm not positive.

"The crankshaft position sensor (CKP sensor) is a dual Hall effect magnetic switch, which is actuated by the dual vane armature on the crankshaft pulley hub. The crankshaft position sensor generates two separate signals, PIP (profile ignition pick-up) and CID (cylinder identification). The PIP signal provides base timing and rpm information, while the CID signal is used to synchronize the ignition coils . Initial timing (base timing) is set at 10 ± 2 degrees BTDC and is not adjustable.

The main function of the ignition control module is to switch between ignition coils and trigger the ignition coils to spark. The ignition control module receives the PIP and CID signals from the crankshaft position sensor, and the SPOUT (spark output) signal from the powertrain control module . During normal operation, PIP is passed on to the powertrain control module and provides base timing and rpm information. The CID signal provides the ignition control module (ICM) with the information required to switch between the ignition coils for cylinders 1 and 4 and the ignition coils for cylinders 2 and 3. The SPOUT (spark output) signal (from the powertrain control module) contains the optimum spark timing and dwell time information. The spark angle is determined by the rising edge of the SPOUT signal because that is when coil current "turns off" and spark occurs. The dwell time is controlled or varied by varying the duty cycle (duration) of the SPOUT signal. Current flows in an ignition coil (dwell) when SPOUT is "low". This feature is called CCD (computer controlled dwell). Therefore, with the proper inputs of PIP, CID and SPOUT the ignition control module turns the ignition coils on and off in the proper sequence for spark control.

During some faults of the ignition control module, the Failure Mode Effects Management (FMEM) portion of the ignition control module will maintain vehicle operation. If the ignition control module does not receive the SPOUT input, it will automatically turn the ignition coils on and off using the PIP signal. However, this will result in fixed spark timing (ten degrees BTDC) and a fixed dwell time (no CCD). If the ignition control module does not receive the CID input, random coil synchronization will be attempted by the ignition control module. Therefore, several start attempts may be required to start the engine.

The Ignition Diagnostic Monitor (IDM) is a function of the ignition control module. The ignition control module sends information on system failures to the powertrain control module which stores the information for diagnostic self test. The IDM signal also is used to drive the test tachometer for system diagnosis."

As an aside... I believe the IDM and SPOUT are supposed to be virtually mirror images of one another. They're square-wave signals between the ICM and PCM.