Power Seat Malfunction (Passenger With AKE)
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 |
|---|---|---|---|---|---|
| 3940 | B+ | — | U0246 | — | — |
| 7440 | B+ | — | 1 | — | — |
| 4116 | Serial Data | — | U0261 | — | — |
| 298 | Control | B109E 11 | B109E 13 | B109E 12 | — |
| 297 | Control | B109D 11 | B109D 13 | B109D 12 | — |
| 296 | Control | B109C 11 | B109C 13 | B109C 12 | — |
| 290 | Control | B1098 11 | B1098 13 | B1098 12 | — |
| 289 | Control | B1097 11 | B1097 13 | B1097 12 | — |
| 288 | Control | B1096 11 | B1096 13 | B1096 12 | — |
| 77 | Control | B1A83 11 | B1A83 13 | B1A83 12 | — |
| 76 | Control | B1A82 11 | B1A82 13 | B1A82 12 | — |
| 1250 | Ground | — | U0246 | — | — |
| 1. All power seat and memory functions are inoperative |
Scan Tool Data K40P Passenger Seat Adjuster Memory Module Normal Operation Data List Parameter Values
| Data List | Parameter | Values | Normal Operation |
|---|---|---|---|
| Seat Position Data | Seat Cushion Front Vertical Switch | Inactive/Upward/D | This parameter indicates the ownward state of the seat position switch. |
| Seat Cushion Rear Vertical Switch | Inactive/Upward/D | This parameter indicates the ownward state of the seat position switch. | |
| Seat Horizontal Switch | Inactive/Forward/ | This parameter indicates the Rearward state of the seat position switch. | |
| Seat Back Switch | Inactive/Forward/ | This parameter indicates the Rearward state of the seat position switch. |
Circuit/System Description Battery voltage is supplied at all times to the seat memory control module through a 10 A fuse located in the instrument panel fuse block. This voltage is used by the module for logic power. Battery positive voltage is also supplied at all times to the seat memory control module through a 30 A fuse located in the instrument panel fuse block. This voltage is connected to a power rail internal to the seat memory control module and is used to drive the power seat motors. Each seat motor is controlled by the seat memory control module by applying power and ground through the control circuits to the motor. All motors are reversible. For example, when the seat switch is operated to move the entire seat forward, a serial data message is sent from the seat adjuster switch to the seat memory control module indicating the entire seat forward command. In response to this message, the seat memory control module applies battery voltage through the driver seat horizontal motor forward control circuit and ground through the driver seat horizontal motor rearward control circuit to the motor. The motor runs to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. Diagnostic Aids After servicing the memory seat system it is recommended to move the seat to a central, middle range position, then perform the memory store operation for memory “1”, “2”, and “Exit” or “3” if equipped. Refer to the Owner Manual for storing memory seat positions. Additionally, It is recommended to inform the vehicle owner that the stored memory positions may differ due to the servicing of the seat system. The K40P Passenger Seat Adjuster Memory Module must be awake when measuring voltage from either one of the memory seat switch signal circuits. If the module is not fully awake incorrect voltage readings are possible and may result in misdiagnosing the circuit. The K40P Passenger Seat Adjuster Memory Module must have seat positions stored to each position “1”, “2”, and “Exit” or “3” prior to that position recall functioning. Reference Information Schematic Reference Passenger Seat Schematics Connector End View Reference Master Electrical Component List Description and Operation Power Seats System Description and Operation Memory Seats Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification
- Ignition/Vehicle in Service Mode.
- Verify that no DTCs are set. ⇒ If any DTC is set Refer to Diagnostic Trouble Code (DTC) List - Vehicle. ⇓ If no DTCs are set
- Verify the appropriate passenger scan tool seat switch parameters listed below change between Inactive and Forward/Rearward or Up/Down when pressing the switch. Seat Horizontal Switch Seat Cushion Front Vertical Switch Seat Cushion Rear Vertical Switch Seat Back Switch ⇒ If the parameter does not change Test or replace the S64P Front Seat Adjuster Switch - Passenger. ⇓ If the parameter changes
- Verify the seat directional motors listed below operate while operating the appropriate seat switches in both directions. M50P Front Seat Tilt Adjuster Actuator - Passenger M51P Front Seat Adjuster Actuator - Passenger M55P Front Seat Vertical Adjuster Actuator - Passenger M56P Front Seat Recliner Actuator - Passenger ⇒ If any seat motor does not operate Refer to Circuit/System Testing. ⇓ If all seat motors operate
- A fault is currently not present and may be an intermittent condition. Circuit/System Testing
- Ignition/Vehicle OFF, disconnect the X1 connector at the K40P Passenger Seat Adjuster Memory Module.
- Test for less than 10 Ω between ground circuit terminal 1 and ground. ⇒ If 10 Ω or greater 2.1. Test circuit 1250 for an open/high resistance. ⇒ 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
- Ignition/Vehicle in Service Mode.
- Verify a test lamp illuminates between the B+ circuit terminal 6 and ground. ⇒ If the test lamp does not illuminate. 4.1. Test circuit 7440 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Test circuit 7440 for an open/high resistance. ⇒ 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.
- Ignition/Vehicle OFF, connect the X1 connector at the K40P Passenger Seat Adjuster Memory Module and disconnect the connector at the appropriate seat motor(s) listed below: M50P Front Seat Tilt Adjuster Actuator - Passenger M51P Front Seat Adjuster Actuator - Passenger M55P Front Seat Vertical Adjuster Actuator - Passenger M56P Front Seat Recliner Actuator - Passenger
- Connect a test lamp between control circuit terminal 1 and control circuit terminal 3.
- Ignition/Vehicle in Service Mode.
- Verify the test lamp turns ON while operating the appropriate seat switch in the Up/Down or Forward/Rearward directions. ⇒ If the test lamp remains OFF during either of the commands 8.1. Test the appropriate circuits listed below for a short to ground: M50P Front Seat Tilt Adjuster Actuator - Passenger = Circuit 297 and circuit 298 M51P Front Seat Adjuster Actuator - Passenger = Circuit 290 and circuit 296 M55P Front Seat Vertical Adjuster Actuator - Passenger = Circuit 288 and circuit 289 M56P Front Seat Recliner Actuator - Passenger = Circuit 76 and circuit 77 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 8.2. Test the appropriate circuits listed below for an open/high resistance: M50P Front Seat Tilt Adjuster Actuator - Passenger = Circuit 297 and circuit 298 M51P Front Seat Adjuster Actuator - Passenger = Circuit 290 and circuit 296 M55P Front Seat Vertical Adjuster Actuator - Passenger = Circuit 288 and circuit 289 M56P Front Seat Recliner Actuator - Passenger = Circuit 76 and circuit 77 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 8.3. Replace the K40P Passenger Seat Adjuster Memory Module. ⇓ If the test lamp turns ON during each of the commands
- Test or replace the appropriate seat motor listed below: M50P Front Seat Tilt Adjuster Actuator - Passenger M51P Front Seat Adjuster Actuator - Passenger M55P Front Seat Vertical Adjuster Actuator - Passenger M56P Front Seat Recliner Actuator - Passenger Component Testing Seat Motor
- Ignition/Vehicle OFF, disconnect the connector at the appropriate seat actuator listed below: M50P Front Seat Tilt Adjuster Actuator - Passenger M51P Front Seat Adjuster Actuator - Passenger M55P Front Seat Vertical Adjuster Actuator - Passenger M56P Front Seat Recliner Actuator - Passenger
- Install a 30 A fused jumper wire between control terminal 1 and 12 V.
- Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD / REARWARD / UP / DOWN function. ⇒ If the motor does not perform the FORWARD / REARWARD / UP / DOWN function Replace the seat motor. ⇓ If the motor performs the FORWARD / REARWARD / UP / DOWN function
- Reverse the jumper wires; the motor should perform FORWARD / REARWARD / UP / DOWN function. ⇒ If the motor does not perform the FORWARD / REARWARD / UP / DOWN function Replace the seat motor. ⇓ If the motor performs the FORWARD / REARWARD / UP DOWN function
- All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Front Seat Adjuster Switch Replacement Control Module References for K40P Passenger Seat Adjuster Memory Module replacement, programming and setup