GM Service Manual Online
For 1990-2009 cars only

Internal Wiring Harness Check (1999 4T40-E/4T45-E)

Step

Action

Value(s)

Yes

No

1

  1. Install the J 39775 jumper harness on the transmission side of the 20-way connector, if needed.
  2. Using the J 39200 digital multimeter (DMM) and J 35616-A connector test adapter kit, measure the resistance between terminals A and E: the 1-2 shift solenoid valve.

Is the resistance within the values shown?

19-24 ohms @ 20°C (68°F)

24-31 ohms @ 100°C (212°F)

Go to Step 3

Go to Step 2

2

  1. Disconnect the internal transmission harness from the 1-2 shift solenoid valve.
  2. Measure the resistance of the 1-2 shift solenoid valve.

Is the resistance within the values shown?

19-24 ohms @ 20°C (68°F)

24-31 ohms @ 100°C (212°F)

Go to Step 14

Go to Step 16

3

Measure the resistance between terminals B and E: the 2-3 shift solenoid valve.

Is the resistance within the values shown?

19-24 ohms @ 20°C (68°F)

24-31 ohms @ 100°C (212°F)

Go to Step 5

Go to Step 4

4

  1. Disconnect the internal transmission harness from the 2-3 shift solenoid valve.
  2. Measure the resistance of the 2-3 shift solenoid valve.

Is the resistance within the values shown?

19-24 ohms @ 20°C (68°F)

24-31 ohms @ 100°C (212°F)

Go to Step 14

Go to Step 16

5

Measure the resistance between terminals T and E: the TCC solenoid valve.

Is the resistance within the values shown?

10-11 ohms @ 20°C (68°F)

13-15 ohms @ 100°C (212°F)

Go to Step 7

Go to Step 6

6

  1. Disconnect the internal transmission harness from the TCC solenoid valve.
  2. Measure the resistance of the TCC solenoid valve.

Is the resistance within the values shown?

10-11 ohms @ 20°C (68°F)

13-15 ohms @ 100°C (212°F)

Go to Step 14

Go to Step 16

7

Measure the resistance between terminals C and D: the pressure control solenoid valve.

Is the resistance within the values shown?

3-5 ohms @ 20°C (68°F)

4-7 ohms @ 100°C (212°F)

Go to Step 9

Go to Step 8

8

  1. Disconnect the internal transmission harness from the pressure control solenoid valve.
  2. Measure the resistance of the pressure control solenoid valve.

Is the resistance within the values shown?

3-5 ohms @ 20°C (68°F)

4-7 ohms @ 100°C (212°F)

Go to Step 14

Go to Step 16

9

Measure the resistance between terminals S and V: the A/T ISS.

Is the resistance within the values shown?

625-725 ohms @ 20°C (68°F)

750-835 ohms @ 100°C (212°F)

Go to Step 11

Go to Step 10

10

  1. Disconnect the internal transmission harness from the A/T ISS.
  2. Measure the resistance of the A/T ISS.

Is the resistance within the values shown?

625-725 ohms @ 20°C (68°F)

750-835 ohms @ 100°C (212°F)

Go to Step 14

Go to Step 16

11

Measure the resistance between terminals M and L : the TFT sensor.

Is the resistance within the values shown?

3106-3923 ohms @ 20°C (68°F)

164-190 ohms @ 100°C (212°F)

Go to Step 13

Go to Step 12

12

  1. Disconnect the internal transmission harness from the TFP manual valve position switch.
  2. Measure the resistance of the TFT sensor by placing the meter leads between terminals E and F of the TFP manual valve position switch.

Is the resistance within the values shown?

3106-3923 ohms @ 20°C (68°F)

164-190 ohms @ 100°C (212°F)

Go to Step 14

Go to Step 16

13

Using the J 39200 (DMM) and J 35616-A , measure the resistance of the internal transmission harness from pins A, B, C, D, E, L, M, S, T and V of the transmission 20-way connector to the transmission case.

Is the resistance greater than the value shown?

250 K ohms

System OK

Go to Step 15

14

Inspect for high resistance:

    • Inspect the transmission wiring for poor electrical connections at the transmission 20-way connector and at the component connectors.
    • Look for possible bent, backed out, deformed, or damaged terminals.
    • Inspect for reduced terminal tension.

Was the condition found?

--

Go to Step 1

Go to Step 15

15

Replace the internal wiring harness.

Refer to Wire Harness Disconnect and Wiring Harness Removal in the 4T40-E/4T45-E Section of the Transmission Unit Repair Manual.

Is the replacement complete?

--

Go to Step 1

--

16

Replace the component.

Refer to Repair Instructions in the 4T40-E/4T45-E Section of the Transmission Unit Repair Manual.

Is the replacement complete?

--

Go to Step 1

--