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| Ford DIS System |
Crankshaft timing sensor
DIS module
Two ignition coil packs
Spark angle portion of EEC-IV
Crankshaft Timing Sensor
The crankshaft timing sensor is a dual hall effect magnetic switch, which is actuated by the dual vane cup on the crankshaft pulley hub assembly. This 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 degrees BTDC and is not adjustable. Ignition Coil Packs
DIS Module
Failure Mode Effects Management
During some DIS system faults, the Failure Mode Effects Management (FMEM) portion of the DIS ignition module will maintain vehicle operation. If the DIS ignition 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 DIS ignition module does not receive the CID input during engine cranking, random coil synchronization will be attempted by the module. Therefore, several start attempts (cycling the ignition from OFF to START) may be required to start the engine. If the DIS module loses CID input while engine is running, the module will remember the proper firing sequence and continue to fire to maintain engine operation.
Dual Plug Inhibit
Dual Plug Inhibit (DPI) is a function of the EEC-IV that is only used when the vehicle is being started at temperatures -7° C (20° F) and below. During engine cranking, the EEC-IV will only fire the spark plugs on the right hand side of the engine. When the engine has started, the EEC-IV will send a signal to the DIS module to start normal dual plug operation.
Ignition Diagnostic Monitor
The Ignition Diagnostic Monitor (IDM) is a function of the DIS module. The DIS module sends information on system failures to the EEC-IV which stores the information for diagnostic self test. The IDM signal also is used to drive the vehicle instrument tachometer, and test tachometer for system.
Testing
You can find a good DIS testing procedure using a breakout box HERE. The factory pinpoint test mentions using a breakout box (BOB). You can do the same test without a breakout box. The BOB just lets you connect to each wire non-intrusively. Without the BOB, you have to locate each wire and probe directly into the wire. The pinpoint tests refer to overlays and test harnesses, just read over the test first and get an idea what the test is checking, and then you can do the test without using the BOB and associated equipment.
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| DIS Break out box |
