Rear Riser Sensor Out Of Range Low

Monitored & Set Condition

1. When Monitored: Ignition on.
2. Set Condition: This condition is immediately set when the seat motor potentiometer feeds a value lower than the Memory Heated Seat/Mirror Module has stored in EEPROM.

Possible Causes:

• Rear Riser Position Signal Circuit Short To Ground
• Rear Riser Position Signal Circuit Open
• Seat Sensor 5-Volt Supply Short To Ground
• Seat Sensor 5-Volt Supply Open
• Rear Riser Sensor Low
• Memory Heated Seat Mirror Module

Testing

1. Turn ignition off. Ensure Memory Heated Seat/Mirror Module (MHSMM) is properly connected. Disconnect driver power seat front riser motor sensor connector. Turn ignition on. Measure voltage on driver power seat rear riser motor sensor connector terminal No. 1, seat sensor 5-volt supply circuit (Brown/White wire). See Figure . If voltage is more than 4.5 volts, leave driver power seat rear riser motor sensor connector disconnected and go to step  4 . If voltage is 4.5 volts or less, leave driver power seat rear riser motor sensor connector disconnected and go to next step.
2. Turn ignition off. Disconnect MHSMM connector C2. Measure resistance between ground and MHSMM connector C2 terminal No. 6, seat sensor 5-volt supply circuit (Brown/White wire). See Figure . If resistance is less than 1000 ohms, repair short to ground in Brown/White wire. If resistance is 1000 ohms or more, leave connectors disconnected and go to next step.
3. Measure resistance of seat sensor 5-volt supply circuit (Brown/White wire) between driver power seat rear riser motor sensor connector terminal "C" and MHSMM connector C2 terminal No. 6. If resistance is less than 5 ohms, replace MHSMM. See MEMORY HEATED SEAT/MIRROR MODULE  under REMOVAL & INSTALLATION. If resistance is 5 ohms or more, repair open in Brown/White wire.
4. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, monitor REAR RISER POSITION SENSOR voltage. Connect a fused jumper wire between driver power seat rear riser motor sensor connector terminal "C", seat sensor 5-volt supply circuit (Brown/White wire) and terminal "B", rear riser position signal circuit (Light Blue/Red wire). If voltage is more than 4.5 volts, replace seat track assembly. See POWER SEATS article. If voltage is 4.5 volts or less, leave driver power seat front riser motor sensor connector disconnected and go to next step.
5. Turn ignition off. Remove jumper wire. Disconnect MHSMM connector C1. Measure resistance between ground and MHSMM connector C1 terminal No. 3, rear riser position signal circuit (Light Blue/Red wire). See Figure . If resistance is less than 1000 ohms, repair short to ground in Light Blue/Red. If resistance is 1000 ohms or more, leave connectors disconnected and go to next step.
6. Measure resistance between ground and MHSMM connector C1 terminal No. 3, rear riser position signal circuit (Light Blue/Red wire). If resistance is less than 5 ohms, replace MHSMM. See MEMORY HEATED SEAT/MIRROR MODULE  under REMOVAL & INSTALLATION. If resistance is 5 ohms or more, repair open in Light Blue/Red wire.