DTC 51 Switch Condition Signal Circuit CIRCUIT DESCRIPTION Park/Neutral Position Switch The ECM uses the signals from the park/neutral position switch to determine whether the transmission is in park or neutral, or in some other position. Air Conditioning Switch Signal The ECM uses the output from the air conditioning switch to determine whether or not the air conditioning is operating so that it can increase the idling speed of the engine if necessary. Throttle Position Sensor IDL Signal The IDL contacts are mounted in the throttle position sensor, and detects the idle condition. DTC No. | Diagnostic Trouble Code Detecting Condition | Trouble Area 51 | (1) 3 sec. or more after engine starts with closed throttle position switch OFF (IDL1) (2) Park/neutral position switch: OFF (Shift position in "R", "D", "2" or "1" position.) (3) A/C switch ON | • Throttle position sensor IDL circuit • Accelerator pedal and cable • Park/neutral position switch • A/C switch circuit • ECM HINT: In this circuit, diagnosis can only be made in the test mode. WIRING DIAGRAM Engine Control Module B+ 76 NSW E9 7 B B-W 6 ST 4 B 13 B-W B-W 1J 1K J2 Ignition Switch J/B No.1 B-W 6 Park/Neutral Position Switch 5 4 1J J/B No.1 4 1B B B 3 B EA1 B+ 2 2 2 5 1 1 EA2 1 W-L 4 SW6 MGC 6 L-R 31 L-R 34 A/C H13 A14 A14 I11 E10 Starter Relay B A/C Amplifier B+ 3 2 S3 1 Heater Control Switch Starter IDL 64 E9 J/B No.2 4 3 R Throttle Position Sensor ALT MAIN 1 2A 2 B 1 L-O 8 L-O 10 L-O 25 4 W-B BR-B 65 E2 B3 F2 T13 T7 E9 Battery Theft Deterrent and Door Lock Control ECU E1 P21139