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P0110 Fault Code on 1996 Nissan 300ZX: IAT Sensor Diagnosis & Testing Guide

Model: Nissan 300ZX Fault Code: P0110 Posted: 2006-10-05 23:05

I own a 1996 Nissan 300ZX and recently picked up a persistent DTC P0110 from the ECU. After clearing the codes, only P0110 returned — it appeared after driving about 10 miles and reappeared upon restarting the engine. AutoZone identified this as an Intake Air Temperature (IAT) sensor issue, with a replacement part priced at $90. My question: Should I replace the IAT sensor, or should I first troubleshoot other components? Is there a way to test it without replacing? Initially, several other codes were detected but cleared after reset and did not return during subsequent driving (50+ miles in city and highway conditions with multiple restarts): - P0115: Coolant temperature sensor malfunction - P0125: Insufficient coolant temperature for closed-loop fuel control - P0733: Gear 3 ratio incorrect - P-1705: Unknown cause; AutoZone states this is a manufacturer-specific code, likely only Nissan technicians can interpret. The temperature gauge reads consistently in the middle (between hot and cold) when the engine is warm. I believe P0733 may be related to transmission performance — however, shifting behavior appears normal. I'm looking for clear guidance on how to diagnose and test the IAT sensor properly before replacing it. Any technical steps or diagrams available for this 1996 model?

Related fault codes
P0110
Comments (2)
Anonymous 2006-10-05 23:42

Begin by visually inspecting the IAT sensor, its wiring harness, and connections for damage, corrosion, or loose fittings. Use a multimeter or a ScanGauge to test the sensor's output voltage and resistance under controlled conditions.

Anonymous 2006-10-06 20:44

Here’s a step-by-step diagnostic procedure for P0110 on your 1996 Nissan 300ZX: Step 1: Power Supply Check - Disconnect the IAT sensor harness connector. With the ignition ON, measure voltage between terminal "2" (Blue wire) and ground. If reading is approximately 5 volts, proceed to next step. If not, verify continuity of the Green/Red wire in the harness between the IAT sensor and ECM. Repair any damaged wiring or connectors as needed. Step 2: Ground Circuit Check - Turn ignition OFF. Test continuity between terminal "1" (Black wire) on the IAT sensor harness and engine ground. If continuity exists, move to next step. If not, verify continuity between the IAT sensor and ECM, and between the IAT sensor and A/T control unit. Repair any faulty connections. Step 3: Component Inspection - Check for physical damage or contamination on the IAT sensor itself. Inspect the ECM and harness for corrosion or pin displacement. Repair as necessary. If no issues are found, ensure the ignition is off before proceeding. Step 4: Resistance Test - Measure resistance between the IAT sensor terminals under these conditions: - At intake air temperature of 68°F: resistance should be 2100–2900 ohms. - At intake air temperature of 176°F: resistance should be 270–380 ohms. - If readings fall outside these ranges, replace the IAT sensor. If within range, inspect ECM connector terminals for damage or corrosion; repair or replace as needed. Final Check: - Ensure all electrical components and connectors are securely connected. - Perform a test drive under conditions that may trigger the fault. - Recheck for DTCs after driving. - If symptoms or codes return, inspect ECM terminals for bending, corrosion, or damage. If no issues are found, consider replacing the ECM as a last resort. This process helps isolate whether the issue is with the sensor or elsewhere in the system. Hope this helps — Mike