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Home >> Ford >> 1994 >> Taurus SHO, 3.2 P >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Diagnosis - AXOD-E >> Circuit/Pinpoint Tests >> Circuit Test Tb - Transmission Control Switch (TCS), Transmission Control Switch, Module (TCSM) & Transmission Control Indicator Light >> Diagnostic Aids
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Diagnostic Aids

Perform this test only when directed by QUICK TEST . This test is intended to diagnose:

To prevent replacing good components, be aware the following non-EEC related areas may be at fault:

TEST PIN NO. 41 (TCS) WIRE COLOR IDENTIFICATION

Application Wire Color
3.2L SHO White/Light Green
All Others Tan/Light Green
TEST PIN NO. 14 (TCIL) WIRE COLOR IDENTIFICATION

Application Wire Color
3.2L SHO Orange/Yellow
TEST PIN NO. 37 OR 57 (VPWR) WIRE COLOR IDENTIFICATION

Application Wire Color
All Models Red
NOTE: A break in step numbering sequence occurs at this point. Procedure starts at step 2). No test procedures have been omitted.

  1. 2) Code 632 Or 653

    Code 632 or 653 indicates that the TCS was not cycled between engine ID Code and WOT check during KOER SELF-TEST. Possible causes for this fault are:
    • Faulty TCS or switch was not cycled during SELF-TEST.
    • Shorted wiring harness.
    • Faulty Powertrain Control Module (PCM).
    • Open in wiring harness or fuse.

    If TCS cycled during KOER SELF-TEST, go to step  4). If TCS did not cycle during KOER SELF-TEST, repeat KOER SELF-TEST while cycling TCS.

  2. 3) Code 623 or 631

    Code 623 or 631 indicates transmission control indicator light circuit fault during KOEO SELF-TEST. Possible causes for this fault are:
    • Burned out bulb.
    • Open or shorted wiring harness.

    If TCS cycled during KOEO SELF-TEST, go to step  5). If TCS did not cycle during KOEO SELF-TEST, repeat KOER SELF-TEST while cycling TCS.

  3. 4) Check TCS Circuit

    Turn ignition off. Disconnect 60-pin PCM connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Turn ignition on. Measure voltage between test pin No. 41 and test pin No 40 or 60 while cycling TCS several times. If voltage cycles replace PCM. Remove breakout box, reconnect all components, and repeat QUICK TEST . If voltage does not cycle, go to next step if diagnosing a trouble code or step  7) if diagnosing a driveability symptom.

  4. 5) Check Circuits For Short To Ground

    Turn ignition off. Leave PCM disconnected from breakout box. Disconnect TCS connector. Inspect connector for damage and repair as necessary. Measure resistance between test pin No. 41 and test pin 40 or 60. Also, measure resistance between test pin No. 55 (14 on 3.2L SHO) and test pin No. 40 or 60. If each reading is more than 10 k/ohms, go to next step (Code 623 or 631) or step 8) (Code 632 or 653). If any reading is 10 k/ohms or less, repair short circuit. Repeat QUICK TEST . If code is still present, go to step  7).

  5. 6) Check Power Through TCIL Circuit

    Turn ignition off. Leave PCM disconnected from breakout box. Measure voltage between test pin No. 55 (14 on 3.2L SHO) and test pin No. 40 or 60. If voltage is more than 10.5 volts, replace PCM. Remove breakout box, reconnect all components, and repeat QUICK TEST . If voltage is 10.5 volts or less, go to next step.

  6. 7) Check Output Driver Voltage Signal

    Leave PCM disconnected from breakout box. Turn ignition on. Measure voltage between test pin No. 55 (14 on 3.2L SHO) and test pin No. 40 or 60. If voltage is 2 volts or more, go to next step. If voltage is less than 2 volts, check bulb and fuse. Replace as necessary. If bulb and fuse are okay, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST .

  7. 8) Check TCS & TCIL Circuits

    Turn ignition off. Leave PCM disconnected from breakout box. Ensure TCS is disconnected. Measure resistance of Purple/Orange wire between KEY POWER terminal of fuse No. 1 at instrument panel fuse block and TCS wiring harness connector. Also, measure resistance between test pin No. 41 at breakout box and Purple/Orange wire at TCS wiring harness connector. If any reading is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST . If each reading is less than 5 ohms, go to next step.

  8. 9) Check For Short To Power

    Turn ignition off. Leave PCM disconnected from breakout box. Ensure TCS is disconnected. Measure resistance between test pin No. 41 and test pin 37 or 57. Also, measure resistance between test pin No. 55 (14 on 3.2L SHO) and test pin No. 37 or 57. If each reading is more than 10 k/ohms, replace TCS switch. Remove breakout box, reconnect all components, and repeat QUICK TEST . If any reading is 10 k/ohms or less, repair short circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST .
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