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P0117 Fault Code on 1996 Mercury Grand Marquis: Fix and Gauge Issues

Model: 1996 Mercury Grand Marquis Fault Code: P0117 Posted: 2014-03-18 12:29

I recently replaced the Engine Coolant Temperature (ECT) sensor with code P0117 on my 1996 Mercury Grand Marquis, but the check engine light remains illuminated. Additionally, the temperature gauge has stopped working. However, the vehicle runs more smoothly than before. My car has an 8-cylinder 4.6L engine and is currently at 137,000 miles. Can anyone confirm if this issue might be related to a faulty sensor or wiring? I'm looking for accurate troubleshooting steps involving the P0117 code specifically on this model year and trim.

Related fault codes
P0117
Comments (1)
Anonymous 2014-03-18 16:06

I'll double-check the setup — there are two coolant temperature sensors in total. One serves the dashboard gauge, while the other is used by the Powertrain Control Module (PCM). Both are typically located on the front coolant crossover pipe near the manifold, positioned on either side of the alternator. It's possible that replacing only one sensor or a miswiring could cause both the check engine light and gauge malfunction.