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Driver's Thermistor Out Of Range High

NOTE: Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS after each repair.
  1. Raise seat to highest position to access seat connectors. Turn ignition off. Disconnect driver's heated seat cushion 4-pin connector located at rear of seat. Using DVOM, measure resistance between driver's heated seat cushion connector terminals No. 3 (Black/Red wire) and No. 4 (Black/Red wire). Ensure seat is at room temperature. If resistance is greater than 800 ohms, go to next step. If resistance is less than 800 ohms, sensor is shorted. Replace driver's heated seat cushion. See SEAT CUSHION under REMOVAL & INSTALLATION in POWER SEATS - GRAND CHEROKEE article.
  2. Disconnect Heated Seat Module (HSM) C1 connector located at front of seat. Turn ignition on. Using DVOM, measure voltage between ground and HSM C1 connector terminal No. 9 (Light Blue/Black wire). See Figure . If voltage is less than 5.5 volts, go to next step. If voltage is greater than 5.5 volts, repair short to voltage in Light Blue/Black wire between HSM and driver's heated seat cushion.
  3. Using DVOM, measure voltage between ground and HSM C1 connector terminal No. 9 (Light Blue/Black wire). If any voltage is indicated, repair Light Blue/Black wire for short to 5 volt supply (Black/Red wire or Brown/White wire). If no voltage is indicated, go to next step.
  4. Turn ignition off. Using DVOM, measure resistance between ground and HSM C1 connector terminal No. 18 (Brown/White wire). If resistance is less than 1000 ohms, repair short to ground in Brown/White wire between HSM and driver's heated seat cushion. If resistance is greater than 1000 ohms, replace HSM. See MEMORY HEATED SEAT MODULE, HEATED SEAT MODULE OR MEMORY SEAT MODULE  under REMOVAL & INSTALLATION.
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