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Driver's Thermistor Out Of Range Low

NOTE: Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS after each repair.
  1. Raise seat to highest position to access seat connectors. Disconnect driver's heated seat cushion Black 4-pin connector located at rear of seat. Turn ignition on. Using DVOM, measure voltage between ground and driver's heated seat cushion connector terminal No. 4 (Brown/White wire, harness side). If voltage is less than 4.5 volts, go to next step. If voltage is greater than 4.5 volts, go to step  3 .
  2. Turn ignition off. Disconnect Heated Seat Module (HSM) C1 connector located at front of seat. Using DVOM, measure resistance of Brown/White wire between driver's heated seat cushion connector terminal No. 4 and HSM C1 connector terminal No. 18. See Figure . If resistance is less than 5 ohms, replace HSM. See MEMORY HEATED SEAT MODULE, HEATED SEAT MODULE OR MEMORY SEAT MODULE  under REMOVAL & INSTALLATION. If resistance is greater than 5 ohms, repair open in Light Blue/Black wire between HSM and driver's heated seat cushion.
  3. Using DVOM, measure resistance between driver's heated seat cushion connector terminal No. 3 (Black/Red wire) and No. 4 (Black/Red wire). Ensure seat is at room temperature. If resistance is less than 70 k/ohms, go to next step. If resistance is greater than 70 k/ohms, replace driver's heated seat cushion. See SEAT CUSHION under REMOVAL & INSTALLATION in POWER SEATS - GRAND CHEROKEE article.
  4. Using DVOM, measure resistance between ground and HSM C1 connector terminal No. 9 (Light Blue/Black wire). See Figure . If resistance is greater than 1000 ohms, go to next step. If resistance is less than 1000 ohms, repair short to ground in Light Blue/Black wire between HSM and driver's heated seat cushion.
  5. Using DVOM, measure resistance between ground and driver's heated seat cushion connector terminal No. 3 (Black/Red wire). If resistance is greater than 1000 ohms, go to next step. If resistance is less than 1000 ohms, replace driver's heated seat cushion. See SEAT CUSHION under REMOVAL & INSTALLATION in POWER SEATS - GRAND CHEROKEE article.
  6. Using DVOM, measure resistance of Light Blue/Black wire between driver's heated seat cushion connector terminal No. 3 and HSM C1 connector terminal No. 9. If resistance is less than 5 ohms, replace HSM. See MEMORY HEATED SEAT MODULE, HEATED SEAT MODULE OR MEMORY SEAT MODULE  under REMOVAL & INSTALLATION. If resistance is greater than 5 ohms, repair open in Light Blue/Black wire between HSM and driver's heated seat cushion.
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