GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T80-E 🢒 Transmission Fluid Pressure Manual Valve Position Switch Resistance Check

TFP Manual Valve Position Switch Resistance Check

Step

Action

Value(s)

Yes

No

1
  1. Connect the J 39775 jumper harness to the transmission side of the 20-way connector.
  2. Using the J 39200 digital multimeter (DMM) and J 35616-A connector test adapter kit, measure the resistance from terminal N to ground.

Is the resistance less than the specified value?

1000 ohms

Go to Step 2

Go to Step 3

2

Inspect circuit 1224 of the automatic transmission wiring harness for a short to ground. Refer to General Electrical Diagnosis in Wiring Systems.

Was the condition found?

--

Go to Step 14

Go to Step 13

3

Measure the resistance from terminal R to ground.

Is the resistance less than the specified value?

1000 ohms

Go to Step 4

Go to Step 5

4

Inspect circuit 1225 of the automatic transmission wiring harness for a short to ground. Refer to General Electrical Diagnosis in Wiring Systems.

Was the condition found?

--

Go to Step 14

Go to Step 13

5

Measure the resistance from terminal P to ground.

Is the resistance less than the specified value?

1000 ohms

Go to Step 6

Go to Step 7

6

Inspect circuit 1226 of the automatic transmission wiring harness for a short to ground. Refer to General Electrical Diagnosis in Wiring Systems.

Was the condition found?

--

Go to Step 14

Go to Step 13

7
  1. Run the engine at idle.
  2. Place the gear select lever in the REVERSE position.
  3. Measure the resistance from terminal N to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 9

Go to Step 8

8

Inspect circuit 1224 of the automatic transmission wiring harness for an open. Refer to General Electrical Diagnosis in Wiring Systems.

Was the condition found?

--

Go to Step 14

Go to Step 13

9

Measure the resistance from terminal R to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 11

Go to Step 10

10

Inspect circuit 1225 of the automatic transmission wiring harness for an open. Refer to General Electrical Diagnosis in Wiring Systems.

Was the condition found?

--

Go to Step 14

Go to Step 13

11
  1. Place the gear select lever in the D4 position.
  2. Measure the resistance from terminal P to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 13

Go to Step 12

12

Inspect circuit 1226 of the automatic transmission wiring harness for an open. Refer to General Electrical Diagnosis in Wiring Systems.

Was the condition found?

--

Go to Step 14

Go to Step 13

13

If no open or shorts to ground were found, replace the automatic transmission fluid pressure manual valve position switch. Refer to Unit Repair.

Is the replacement complete?

--

Go to Step 15

--

14

Replace the automatic transmission wiring harness. Refer to Unit Repair.

Is the replacement complete?

--

Go to Step 15

--

15

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
    4. 3.1. Move the gear select through all of the ranges.
    3.2. Ensure that the vehicle achieves an upshift.
  4. Select Specific DTC.
  5. Enter DTC P1810.

Has the test run and passed?

--

System OK

Go to Step 9 of DTC P1810