Passenger Heated Seat Switch Open/Shorted To Ground

Monitored & Set Conditions

1. When Monitored: Ignition on.
NOTE: This DTC can also be set when the ignition switch is cycled with the IOD fuse removed.
2. Set Condition: If the switch is open or grounded the MHSMM will have a loss of switch feed back and this code will set immediately. Once the condition is resolved, the switch will return to it's normal operation.

Possible Causes:

• Fused Ignition Switch Output (Run/St) Open
• Passenger Seat Heater Switch MUX Circuit Open
• Erase And Read MHSMM DTC
• Passenger Heated Seat Switch
• Passenger Seat Heater Switch MUX Circuit Short To Ground
• Memory Heated Seat Mirror Module

Testing

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, select BODY MEMORY SEAT MODULE, then retrieve DTCs. If any Memory Heated Seat/Mirror Module (MHSMM) DTCs are present, go to next step. If no MHSMM DTCs are present, go to step  3 .
NOTE: Cycling ignition switch with Ignition Off-Draw (IOD) fuse removed may set this DTC. IOD fuse is located in Power Distribution Center (PDC). Fuses are identified on label located inside PDC cover.
2. Using scan tool, clear MHSMM DTCs. Start engine and allow it to run for one minute while operating heated seat switch. Using scan tool, retrieve MHSMM DTCs. If PASSENGER HEATED SEAT SWITCH OPEN/SHORTED TO GROUND DTC resets, go to step  4 . If PASSENGER HEATED SEAT SWITCH OPEN/SHORTED TO GROUND DTC does not reset, fault may be intermittent. Check related wiring and connectors for poor connections or damage to wiring harness. See WIRING DIAGRAMS  . Repair any problems found as necessary. If no problems are found, check if any Technical Service Bulletins (TSBs) apply to vehicle. If no TSBs apply, test is complete.
3. Turn ignition off. Disconnect passenger heated seat switch connector. Turn ignition on. Measure voltage on passenger heated seat switch connector terminal No. 4, fused ignition switch output circuit (Dark Blue/White wire). See Figure . If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in Dark Blue/White wire.
4. Turn ignition off. Disconnect MHSMM connector C1. Turn ignition on. Measure voltage between ground and MHSMM connector C1 terminal No. 5, passenger seat heater switch MUX circuit (Tan/Light Green wire). See Figure . If voltage is more than 10 volts, replace MHSMM. See MEMORY HEATED SEAT/MIRROR MODULE  under REMOVAL & INSTALLATION. If voltage is 10 volts or less, leave MHSMM connector C1 disconnected and go to next step.
5. Turn ignition off. Disconnect passenger heated seat switch connector. Measure resistance of passenger seat heater switch MUX circuit (Tan/Light Green wire) between passenger heated seat switch connector terminal No. 6 and MHSMM connector C1 terminal No. 5. See Figure and Figure . If resistance is less than 5 ohms, leave connectors disconnected and go to next step. If resistance is 5 ohms or more, repair open in Tan/Light Green wire.
6. Measure resistance between ground and MHSMM connector C1 terminal No. 5, passenger seat heater switch MUX circuit (Tan/Light Green wire). If resistance is less than 100 ohms, repair short to ground in Tan/Light Green wire. If resistance is 100 ohms or more, replace passenger heated seat switch. See POWER SEATS article.