Power Seats - Memory Switch Inoperative. Cadillac Catera 1999

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 1999 🢒 Catera 🢒 Body and Accessories 🢒 Seats 🢒 Power Seats - Memory Switch Inoperative

Power Seats - Memory Switch Inoperative Memory Seat Inop, No DTC Set

Step	Action	Value(s)	Yes	No
1	Did you perform the Memory Seats System Check?	--	Go to Step 2	Go to Memory Seats System Check
2	Install the scan tool. Establish communication with the driver seat adjuster memory module. Use the scan tool to operate the driver seat in all directions. Does the driver seat operate properly when commanded by the scan tool?	--	Go to Step 3	Go to Step 4
3	Replace the driver seat adjuster switch. Refer to Power Seat Switch Replacement . Is the replacement complete?	--	Go to Step 15	--
4	Remove the driver's seat. Disconnect connector C1 from the driver seat adjuster memory module. Use the DMM in order to measure the voltage between terminal 1 of connector C1 and a known good ground. Is the measured voltage equal to the specified value?	B+	Go to Step 6	Go to Step 5
5	Locate an open or a high resistance in CKT A5 and A70. Repair the open or the high resistance in CKT A5 and A70. Is the repair complete?	--	Go to Step 15	--
6	Use the DMM in order to measure the voltage between terminal 3 of connector C1 and a known good ground. Is the measured voltage equal to the specified value?	B+	Go to Step 8	Go to Step 7
7	Locate an open or a high resistance in CKT A40. Repair the open or the high resistance in CKT A40. Is the repair complete?	--	Go to Step 15	--
8	Turn the ignition switch to the ON position. Use the DMM in order to measure the voltage between terminal 4 of connector C1 and a known good ground. Is the measured voltage equal to the specified value?	B+	Go to Step 10	Go to Step 9
9	Locate an open or a high resistance in CKT X13. Repair the open or the high resistance in CKT X13. Is the repair complete?	--	Go to Step 15	--
10	Use the DMM in order to measure the resistance between terminal 2 of the connector C1 and a known good ground. Is the measured resistance less than the specified value?	5 ohms	Go to Step 12	Go to Step 11
11	Locate an open or a high resistance in CKT F5 and/or F66. Repair the open or the high resistance in CKT F5 and/or F66. Is the repair complete?	--	Go to Step 15	--
12	Use the DMM in order to measure the resistance between terminal 5 of the connector C1 and a known good ground. Is the measured resistance less than the specified value?	5 ohms	Go to Step 14	Go to Step 13
13	Locate an open or a high resistance in CKT F40. Repair the open or the high resistance in CKT F40. Is the repair complete?	--	Go to Step 15	--
14	Replace the driver seat adjuster memory module. Refer to Memory Seat Control Module Replacement . Is the replacement complete?	--	Go to Step 15	--
15	Connect all connectors and components that were disconnected. Program the driver seat adjuster memory module. Refer to Memory Seat Operation . Use the switches to move the seat to its full range in all possible directions. Use the memory and the 3 personal keys to store and to recall the stored settings. Does the driver's memory seat operate properly?	--	Go to Memory Seats System Check	Go to Step 2

Power Seats - Memory Switch Inoperative Driver Switch Inop, DTC 21 Set

Power Seat Systems Components
Power Seats Circuit Description
Memory Seats Schematics

Circuit Description

The driver seat adjuster memory module monitors the voltage of the circuits to the driver seat adjuster switch. When the voltage value on these circuits is not within the specified value, the driver seat adjuster memory module will set DTC 21.

Conditions for Setting the DTC

DTC 21 will set if:

•	the individual switches on the driver seat adjuster switch are shorted or jammed or its circuits are faulty.

•	the driver seat adjuster memory module is faulty.

Action Taken When the DTC Sets

DTC 21 will set and the driver seat will become disabled.

Conditions for Clearing the DTC

DTC 21 will clear when the fault is no longer present.

Diagnostic Aids

•	Check for liquid damage or any other type of physical damage that may have occurred to the driver seat adjuster switch.

•	Check for loose connections at the driver seat adjuster memory module.

Test Description

The following numbers refer to the step numbers on the diagnostic table:

This step checks for a short between the terminals of the driver seat adjuster switch.

This step replaces the driver seat adjuster switch.

This step checks the individual switches of the driver seat adjuster switch.

This step checks the motor.

Step

Action

Value(s)

Yes

Was the Memory Seats System Check performed?

Go to Step 2

Go to Memory Seats System Check

Disconnect the driver seat adjuster switch connector C7 from the driver seat adjuster memory module.
Use the DMM in order to check the resistance between terminal 1 of connector C7A and the following terminals of the driver seat adjuster switch connector C7.

•	Terminal 2 of connector C7A

•	Terminal 3 of connector C7A

•	Terminal 1 of connector C7B

•	Terminal 2 of connector C7B

•	Terminal 3 of connector C7B

•	Terminal 1 of connector C7C

Use the DMM in order to check the resistance between terminal 2 of connector C7A and the following terminals of the driver seat adjuster switch connector C7.

•	Terminal 3 of connector C7A

•	Terminal 1 of connector C7B

•	Terminal 2 of connector C7B

•	Terminal 3 of connector C7B

•	Terminal 1 of connector C7C

Use the DMM in order to check the resistance between terminal 3 of connector C7A and the following terminals of the driver seat adjuster switch connector C7.

•	Terminal 1 of connector C7B

•	Terminal 2 of connector C7B

•	Terminal 3 of connector C7B

•	Terminal 1 of connector C7C

Is the measured resistance within the specified value?

Go to Step 3

Go to Step 4

Use the DMM in order to check the resistance between terminal 1 of connector C7B and the following terminals of the driver seat adjuster switch connector C7.

•	Terminal 2 of connector C7B

•	Terminal 3 of connector C7B

•	Terminal 1 of connector C7C

Use the DMM in order to check the resistance between terminal 2 of connector C7B and the following terminals of the driver seat adjuster switch connector C7.

•	Terminal 3 of connector C7B

•	Terminal 1 of connector C7C

Use the DMM in order to check the resistance between terminal 3 of connector C7B and Terminal 1 of connector C7C of the driver seat adjuster switch connector C7.

Is the measured resistance within the specified value?

Go to Step 5

Go to Step 4

Replace the driver seat adjuster switch. Refer to Power Seat Switch Replacement .

Is the replacement complete?

Go to Step 7

Use the DMM in order to measure the resistance between the following terminals of the driver seat adjuster switch connector C7.

With personal key #1 pressed, terminal 3 of connector C7A and terminal 1 of connector C7C.
With personal key #2 pressed, terminal 3 connector of C7B and terminal 1 of connector C7C.
With personal key #3 pressed, terminal 2 of connector C7B and terminal 1 of connector C7C.
With the memory key pressed, terminal 2 of connector C7A and terminal 1 of connector C7C.
With the backrest forward switch pressed, terminal 3 of connector C7A and terminal 1 of connector C7B.
With the seat backward switch pressed, terminal 3 of connector C7B and terminal 1 of connector C7B.
With the seat rear height down switch pressed, terminal 2 of connector C7B and terminal 1 of connector C7B.
With the seat front height down switch pressed, terminal 2 of connector C7A and terminal 1 of connector C7B.
With the backrest forward switch pressed, terminal 3 of connector C7A and terminal 1 of connector C7A.
With the seat forward switch pressed, terminal 1 of connector C7A and terminal 3 of connector C7B.
With the seat rear height up switch pressed, terminal 1 of connector C7A and terminal 2 of connector C7B.
With the seat front height up switch pressed, terminal 2 of connector C7A and terminal 1 of connector C7A.

Is the measured resistance for all of the measurements less than the specified value?

5 ohms

Go to Step 6

Go to Step 4

Replace the driver seat adjuster memory module. Refer to Memory Seat Control Module Replacement .

Is the replacement complete?

Go to Step 7

Connect all connectors and components that were disconnected.
Program the driver seat adjuster memory module. Refer to Memory Seat Operation .
Use the scan tool to check for any DTC's.
Verify that the driver seat operates properly in all directions and that there are no DTC's present.

Does the driver seat operate properly in all directions and are there no DTC's present?

System OK

Go to Step 1