Chapter 14 Troubleshooting Electronic Control System Problems 359 Copyright by Goodheart-Willcox Co., Inc. Figure 14-29. This diagnostic chart is used when checking a wiring harness on a common automatic transaxle. Note that, even though the second procedure (C9) is a check for continuity (a complete circuit), an ohmmeter must be used. Using an ohmmeter instead of a test light ensures that the internal transaxle parts will not be damaged. (Ford) C8 Check internal axode harness (continuity) Disconnect the internal harness from the solenoid (MCCC/CCC wire connector) NOTE: Do not probe into connector terminals. Connect the positive lead from an ohmmeter to the tester MCCC/CCC jack and negative lead at the Black (91/92 MY) or Brown (93 MY) wire at the MCCC/CCC connector. Record resistance. Should be less than .5 ohms. Next, connect the positive lead from an ohmmeter to the tester VPWR jack and the negative lead at the Red (91/92 MY) or Green (93 MY) wire of the MCCC/CCC connector. Record resistance. Is the resistance less than .5 ohms? Results Yes No Action to take Go to C9. Replace internal harness. Go to C10. C9 Check internal axode harness Check for continuity between BAT (engine ground) and the appropriate wire with an ohmmeter or other low current tester (less than 200 milliamps). Solenoid Wire color 91/92 93 MCCC/CCC Black Brown VPWR Red Green Connection should not show continuity (infinite). Is there continuity? Yes No Replace internal harness. Go to C10. Go to C10. Figure 14-30. Splices are a common source of problems. Carefully inspect the splice for looseness or signs of overheat- ing. (General Motors) Inspect splice Figure 14-31. A close-fitting wiring harness is subject to dam- age. Wiring harnesses should be inspected in areas where they pass through tight spots and near engine and exhaust system parts. (General Motors)
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