Pinpoint Test A - Speed Control Switches

Fig 1: Pinpoint Test A, Schematic

You should enter this Pinpoint Test only when a Service Code 47, 48, or 49 is received in the KOEO Self Test. To prevent the replacement of good components, be aware that the following non-IVSC areas may be at fault:

• Horn Relay
• Fuse

The Pinpoint Test is intended to diagnose only the following:

• Speed control switches
• Brush assembly
• Slip ring assembly
• Wiring Harness
• ECA

1. Service Code 47, did you press the OFF, COAST, ACCEL, and RESUME buttons during the IVSC KOEO Self Test. If no, then repeat IVSC system KOEO Self Test. If yes, then go to step 2 below.
2. Switch does not function, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Measure resistance between Pin 50 and 39 per table below. Rotate steering wheel through its full range while making resistance checks.
   RESISTANCE CHECK
   
   

   DVOM Range (Ohms)	Button Pressed	Resistance Range (Ohms)
   200	OFF	0-4
   200	COAST	114-126
   2000	ACCEL	646-714
   5000	RESUME	2090-2310

   Are resistances within range? If no, then replace switches. If yes, then replace ECA. Do the resistance values fluctuate within the ranges, or go above the ranges, as steering wheel is rotated? If no, then switches are OK. If yes, then CLEAN brushes and slip rings, relubricate slip rings.

3. Service Code 48, did you press the OFF, COAST, ACCEL and RESUME buttons during the IVSC KOEO Quick Test? If no, then repeat IVSC KOEO QUICK TEST. If yes, go to step 4.
4. Switch is stuck, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Use Rotunda DVOM 014-00407 or equivalent, on 5000 ohm scale. Measure resistance between Pin 50 and 39. Is resistance reading between 0 ohms and 2310 ohms? If yes, then replace the switches. If no, then replace ECA.
5. Service Code 49, did you press the OFF, COAST, ACCEL and RESUME buttons during the IVSC KOEO Quick Test. If no, then repeat IVSC KOEO QUICK TEST. If yes, go to step 6.
6. Ground circuit to switches open, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Disconnect speed control switch plug in steering column shroud. DVOM on 200 ohm scale. Measure resistance between Pin 39 and ground terminal in 14290 half of disconnected switch plug. Is resistance reading greater than 5 ohms? If yes, then service open circuit between EEC-IV connector Pin 39 and switch plug ground terminal. If no, then replace ECA.