DIS Ignition and DTC 211

[Rockledge]

214= Cam sensor failure (Loss of CID)
211= Crank sensor failure (PIP=CKP on newer cars)

HOWEVER, since the 211 is not actually the CKP signal from the crank sensor, but rather the SPOUT signal, it is not uncommon to get a 211 triggered by a 214. A 211 by itself is a good, and only indicator that the crank sensor is dying (when it actually gets triggered).

I saw this posted over at SHOtimes and it is not the first time I have heard someone say this. I was hoping that some of the SHO ignition experts around here could help me out, since this has caused me some confusion over the PIP signal and how a 211 code is tripped in DIS.

My understanding of how the system works is that the PIP signal is sent to both the PCM and the DIS Module.The SPOUT signal, on the other hand, is sent only from the PCM to the DIS Module. Click Here for DIS Diagram.

So based on that, I can't see how it can be that the SPOUT signal is responsible for setting the 211 code. It would seem to me that the PCM would be perfectly capable of using the PIP signal it is getting directly from the crank sensor to make the determination whether that same signal is a valid one. Why does the PCM need to look anywhere else?

The following is an excerpt out of the Ford Factory Manual:

The PIP output is a 50-percent duty cycle signal that provides base spark timing information. The CMP sensor signal output is also a 50-percent duty cycle signal, and is required so that the ICM [a/k/a the DIS Module] knows which coil to fire and for fuel timing in the PCM. CID is high (B+) half of the cam revolution (180 degrees) and low the other half.

The PCM determines spark angle using the PIP signal to establish base timing. SPOUT is sent from the PCM to the ICM and serves two purposes: the leading edge fires the coil and the trailing edge controls the dwell time. This feature is called CCD or Computer-Controlled Dwell.

I see nothing in the above quote that would lead me to believe that there is something about SPOUT that generates the 211 code, as opposed to the PIP signal itself. In fact, if anything it leads me think otherwise.

So I guess what I'm looking for here is a little clarification and elaboration on this point. In a nutshell, the question I am posing is: what exactly causes a 211 code to be tripped in the SHO's DIS system?

Thanks for any and all feedback.

 

[SHOZ123]

This is from the CD.



The 3.0L and 3.2L SFI SHO and 3.8L SFI SC EI (Low Data Rate) Ignition System ( «Figure 11») consists of a crankshaft-mounted hall (PIP) sensor, a camshaft-driven hall (CMP)sensor, a 6-tower coil pack, and an Ignition Control Module (ICM).

The Electronic Ignition (EI) low data rate system eliminates the distributor by using multiple ignition coils. Each coil fires two spark plugs at the same time. The plugs are paired so that as one fires during the compression cycle, the other fires during the exhaust stroke. The next time the coil is fired, the plug that was on exhaust will be on compression and the one that was on compression will be on exhaust (the spark in the exhaust cylinder is wasted but little of the coil energy is lost). Three coils are mounted together in a "coil pack". The coil pack has three coil wires, one for each coil. The crankshaft sensor is a digital-output hall device (PIP) that responds to a rotating metallic vane mounted on the crankshaft damper assembly.

The 3.0L and 3.2L SHO CID signal is generated by a hall device mounted at the end of the rear camshaft. The vane cup has one tooth and is driven by the camshaft. The 3.8L SC camshaft sensor is a hall device, but it is mounted in the normal distributor location.

The PIP output is a 50-percent duty cycle signal that provides base spark timing information. The CMP sensor signal output is also a 50-percent duty cycle signal, and is required so that the ICM knows which coil to fire and for fuel timing in the PCM. CID is high (B+) half of the cam revolution (180 degrees) and low the other half ( «Figure 12»).

The PCM determines spark angle using the PIP signal to establish base timing. SPOUT is sent from the PCM to the ICM and serves two purposes: the leading edge fires the coil and the trailing edge controls the dwell time. This feature is called CCD or Computer-Controlled Dwell.

The Ignition Diagnostic Monitor (IDM) is an output from the ICM that provides diagnostic information concerning the ignition system to the PCM for self-test and is also the input signal for the vehicle tachometer. If the CMP circuit fails and an attempt to start the engine is made, the ICM will randomly select one of the three 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 attempts to keep the vehicle drivable in spite of certain system failures that prevent the PCM from providing spark angle or dwell commands. The PCM opens the SPOUT line and the ICM fires the coils directly from the PIP input. This results in a fixed spark angle of 10 degrees and fixed dwell.

DTC 211 means the CMK signal is being generated out of time with the crank signal PIP signal. As suggested first make sure the radio capacitors are working and in good condition or look for acing or loose connections.

 

[Rockledge]

The Ford CD Manual defines DTC 211 as follows:

DTC 211 indicates two successive erratic Profile Ignition Pickup (PIP) pulses occurred, resulting in a possible engine miss or stall.

DTC 211 means the CMK signal is being generated out of time with the crank signal PIP signal.

Paul, I assume you mean the CMP signal? So what you're saying is that a 211 code is generated by comparing the CMP and PIP signals to each other and looking for some sort of "timing anomaly" between the two? Where or what is the source of your information on that?

.

 

[Rockledge]

I have come across some more information which I think casts some further doubt on the proposition that the SPOUT signal or even the CMP signal is a main player in how a 211 code is set in DIS. The following is an excerpt from a Ford OBD-II System Operation Manual describing how CKP and CMP codes are set in the EDIS system. Notice how the tripping of a CKP-related code (P0320) does not rely upon any kind of comparison of the CKP (i.e. PIP) signal to the SAW (i.e. SPOUT) signal or the CMP signal. Instead, the CKP signal is monitored seperately. On the other hand, a CMP-related code (PO340) is indeed tripped as a result of comparing the CMP signal to the CKP (PIP) signal.

Ignition Distributor Ignition systems (TFI) are no longer in production. Electronic Ignition systems (Electronic Distributorless Ignition System - EDIS) systems are being used on all applications. The EDIS system uses a chip to process the 36 (or 40) tooth crankshaft position signal, generate a low data rate PIP signal for the PCM microprocessor and control a 4 or 6 terminal coil pack which fires a pair of spark plugs. One of these spark plugs is on the compression stroke, while the other is on the exhaust stroke. The EDIS chip can be incorporated within the PCM or in a separate ignition control module. The Coil On Plug (COP) system also uses an EDIS chip in the same way as described above, however, each sparkplug has it’s own coil which is fired only once on the compression stroke.

The ignition system is checked by monitoring three (3) ignition signals during normal vehicle operation:

- Profile Ignition Pickup (CKP, commonly known as PIP), the timing reference signal derived from the crankshaft 36-tooth wheel and processed by the EDIS chip. PIP is a 50% duty cycle, square wave signal that has a rising edge at 10 deg BTDC.

- Camshaft IDentification (CMP, commonly known as CID), a signal derived from the camshaft to identify the #1 cylinder.

- Ignition Diagnostic Monitor (IDM), a signal that indicates that the primary side of the coil has fired. This signal is received as a digital pulse width signal from the EDIS chip. The EDIS chip determines if the current flow to the ignition coil reaches the required current (typically 5.5 Amps for COP, 3.0 to 4.0 Amps for DIS) within a specified time period (typically > 200 microseconds for both COP and DIS). The EDIS chip also outputs status information when the engine is not running.

First, the relationship between successive PIP events is evaluated to determine whether the PIP signal is rational. Too large a change in 3 successive PIP indicates a missing or noisy PIP signal (P0320). Next, the CMP edge count is compared to the PIP edge count. If the proper ratio of CMP events to PIP events is not being maintained (for example, 1 CMP edge for every 8 PIP edges for an 8-cylinder engine), it indicates a missing or noisy CMP signal (P0340). Finally, the relationship between IDM edges and PIP edges is evaluated. If there is not an IDM edge (coil firing) for every PIP edge (commanded spark event), the PCM will look for a pattern of failed IDM events to determine which ignition coil has failed. If the ignition coil cannot be identified or if the engine is running and there are no IDM edges, the IDM circuit is malfunctioning (P1351).

I can't think of any reason off hand why DIS would operate differently than EDIS with regard to monitoring the ignition system and storing ignition-related codes?