Lumbar_Bolster_Massage Malfunction (2-Way)

Lumbar/Bolster/Massage Malfunction (2-Way) Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. Diagnostic Fault Information

Circuit Number	Circuit Function	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performan
5040	B+	1	1	—	—
610	Control	1	1	—	—
611	Control	1	1	—	—
1150	Ground	—	1	—	—
7440	B+	2	2	—	—
210	Control	2	2	—	—
211	Control	2	2	—	—
1250	Ground	—	2	—	—
1. The driver lumbar support is inoperative 2. The passenger lumbar support is inoperative

Circuit/System Description The S65 Front Seat Lumbar Switch provides both power and ground to the M53 Front Seat Back Lumbar Motor. When the lumbar switch is in an inactive state, the switch contacts are closed to the switch ground circuit. The M53 Front Seat Back Lumbar Motor is reversible. For example, when the lumbar forward switch is pressed to move the lumbar support forward, battery voltage is applied through the switch contacts and the lumbar motor forward control circuit to the motor. With the lumbar motor rearward control circuit grounded through the closed switch contacts to the lumbar switch ground circuit, the motor runs in order to drive the lumbar support forward toward the occupants back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. Reference Information Driver Seat Schematics Passenger Seat Schematics Connector End View Reference Master Electrical Component List Description and Operation Lumbar Support/Massage Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Circuit/System Verification

1. Ignition/Vehicle in Service Mode.
2. Verify that all lumbar seat functions operate when being controlled by the S65 Front Seat Lumbar Switch. ⇒ If any lumbar function does not operate Refer to Circuit/System Testing. ⇓ If all lumbar functions operate
3. A fault is currently not present and may be an intermittent condition. Circuit/System Testing
4. Ignition/Vehicle OFF, disconnect the connector at the appropriate seat lumbar switch listed below: S65D Front Seat Lumbar Switch – Driver S65P Front Seat Lumbar Switch – Passenger
5. Test for less than 10 Ω between the ground circuit terminal 1 and ground. ⇒ If 10 Ω or greater 2.1. Test the appropriate circuit for an open/high resistance: S65D Front Seat Lumbar Switch – Driver = Circuit 1150 S65P Front Seat Lumbar Switch – Passenger = Circuit 1250 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 2.2. Repair the open/high resistance in the ground connection. ⇓ If less than 10 Ω
6. Ignition/Vehicle in Service Mode.
7. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground. ⇒ If the test lamp does not illuminate 4.1. Test the appropriate circuit for a short to ground: S65D Front Seat Lumbar Switch – Driver = Circuit 5040 S65P Front Seat Lumbar Switch – Passenger = Circuit 7440 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Test the appropriate circuit for an open/high resistance: S65D Front Seat Lumbar Switch – Driver = Circuit 5040 S65P Front Seat Lumbar Switch – Passenger = Circuit 7440 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 4.3. Verify the fuse is OK and there is voltage at the fuse. ⇓ If the test lamp illuminates
8. Ignition/Vehicle OFF, connect the connector at the S65 Front Seat Lumbar Switch.
9. Disconnect the connector at the appropriate seat back lumbar motor listed below: M53D Front Seat Back Lumbar Motor – Driver M53P Front Seat Back Lumbar Motor – Passenger
10. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2 at motor harness.
11. Ignition/Vehicle in Service Mode.
12. Verify the test lamp turns ON when commanding the lumbar support Forward and Rearward using the front seat lumbar switch. ⇒ If the test lamp remains OFF during either of the commands 9.1. Test the appropriate circuits for a short to ground: S65D Front Seat Lumbar Switch – Driver = Circuit 610 and circuit 611 S65P Front Seat Lumbar Switch – Passenger = Circuit 210 and circuit 211 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 9.2. Test the appropriate circuits for an open/high resistance: S65D Front Seat Lumbar Switch – Driver = Circuit 610 and circuit 611 S65P Front Seat Lumbar Switch – Passenger = Circuit 210 and circuit 211 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 9.3. Test or replace the S65 Front Seat Lumbar Switch. ⇓ If the test lamp turns ON during each of the commands
13. Test or replace the M53 Front Seat Back Lumbar Motor. Component Testing Seat Lumbar Switch
14. Ignition/Vehicle OFF, disconnect the connector at the S65 Front Seat Lumbar Switch.
15. Test for infinite resistance between the B+ terminal and each control terminal with the switch in the open position. ⇒ If less than infinite resistance Replace the S65 Front Seat Lumbar Switch. ⇓ If infinite resistance
16. Test for less than 2 Ω between the B+ terminal and each control terminal with the appropriate switch in the closed position. ⇒ If 2 Ω or greater Replace the S65 Front Seat Lumbar Switch. ⇓ If less than 2 Ω
17. Test for less than 2 Ω between the ground terminal and each control terminal with the switch in the open position. ⇒ If 2 Ω or greater Replace the S65 Front Seat Lumbar Switch. ⇓ If less than 2 Ω
18. All OK. Seat Back Lumbar Motor
19. Ignition/Vehicle OFF, disconnect the connector at the M53 Front Seat Back Lumbar Motor.

Note

When performing the following tests, make sure that the lumbar support is not already in the position the test is attempting to produce.

2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.
3. Momentarily install a jumper wire between control terminal 2 and ground. The M53 Front Seat Back Lumbar Motor should momentarily perform the lumbar FORWARD function. ⇒ If the motor does not perform the lumbar FORWARD function Replace the M53 Front Seat Back Lumbar Motor. ⇓ If the motor performs the lumbar FORWARD function
4. Reverse the polarity of jumper wires; the lumbar motor should perform REARWARD function. ⇒ If the motor does not perform the lumbar REARWARD function Replace the M53 Front Seat Back Lumbar Motor. ⇓ If the motor performs the lumbar REARWARD function
5. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Front Seat Lumbar Switch Replacement Front Seat Back Lumbar Replacement