Diagnostic Aids

Following information should be noted during testing:

• When making measurements on a wiring harness, perform both a visual inspection and a continuity test. Inspect terminal connector pins for damage and corrosion when directed to remove a connector.
• When checking voltage drop to GROUND, circuit must have a voltage drop of less than 1.0 volt.
• Battery voltage, COIL PWR or VPWR is any voltage reading within 2 volts of actual battery voltage.
• Spark timing will vary at idle due to feedback spark strategy used to control idle speed.
• DO NOT connect positive lead of diagnostic cable or CKP-CKP sensor tee until directed to do so.
• DO NOT use incandescent light to test CKP+, CKP-, IDM, PIP or SPOUT circuits.
• EEC-IV Breakout Box (T83L-50-EEC-IV) connected to EI diagnostic cable is referred to as breakout box. If a second breakout box is connected to PCM wiring harness connector, it will be referred to as second breakout box. This setup allows testing of ignition components and wiring harness circuits.
• Circuits are identified in all capitals, for example: PIP. Manufacturer's breakout box overlay test terminals are identified by a J prefix, for example: J31 (PIP). This indicates test terminal number and circuit identification.
• When the letter "I" follows the circuit identification, it implies measurement is being taken at ICM, for example: J31 (PIP I). When the letter "S" follows the circuit identification, it implies measurement is being taken at Crankshaft Position Sensor (CKP) for example: J33 (PIP S). When the letter "I" follows the circuit identification, it implies circuit at ICM for example: J31 (PIP I).
• When the letter "C" follows the circuit identification, it implies measurement is being taken at the coil.

Fig 1: EI Diagnostic Cable Diagram (1.9L)