Test STP - Switch To Power: Notes

Fig 1: Brake On/Off Switch Ckt & Connector Terminals ID

Fig 2: Headlight Switch Circuit & Connector Terminal ID

Fig 3: Ignition Switch Circuit & Connector Terminals ID

NOTE: Enter this test only when directed here from SWITCH MONITOR TEST. This test is intended to diagnose following switches and circuits: Brake On-Off (BOO) switch, Headlight (HDLT) switch, Rear Window Defrost (DEF) and Vehicle Start (VST) switch.

CIRCUIT PIN IDENTIFICATION

Circuit	Breakout Box Pin No.	PCM Pin	Wire Color
BOO	2	1Q	White/Green
HDLT	32	1H	White
VST	5	1C	Black/Red

1) Check System Integrity Visually check all wiring, connectors and components for damage, shorting or looseness. If fault is found, repair as necessary. If no fault is found, go to next step.

2) Check Switch Signal To PCM Turn ignition off. Install breakout box, leaving PCM disconnected. Turn ignition on. Measure voltage between breakout box test pin of switch being tested and ground. Check voltage with switch in ON (closed) and OFF (open) positions. See SWITCH PERFORMANCE CHECK. If voltage is as specified and no other problem or code is found, replace PCM. On headlight switch, if voltage is not as specified but headlights work, check for open wire. If headlights do not work, test headlight switch. See STEERING COLUMN SWITCHES article in the ACCESSORIES/SAFETY EQUIPMENT Section. On all other switches, if voltage is not as specified, go to next step.

3) Check Power To Switch Turn ignition off. Disconnect connector of switch to be tested. Turn ignition on. Measure voltage at PWR terminal of switch. If voltage is about battery voltage, go to next step. If voltage is less than battery voltage, repair open PWR wire.

4) Check Switch Continuity Turn ignition off. Disconnect connector of switch to be tested. Measure resistance between switch terminals. Resistance should be less than 5 ohms with switch closed and more than 10,000 ohms with switch open. If resistance is not as specified, replace switch. If resistance is as specified and no other problem or code is found, replace PCM.