Description & Operation

SWITCH MONITOR TEST uses PIDs to check operation of certain switches (and related circuits) that do not set DTCs.

1) Perform Switch Monitor Test

Turn ignition on. Using New Generation STAR (NGS) tester, select and enter the following data:

Select DIAGNOSTIC DATA LINK.
Select PCM-POWERTRAIN CTRL MODULE.
Select PID/DATA MONITOR & RECORD menu.

Select switches listed in SWITCH MONITOR TEST table and check switches ON-OFF operation.

Operate all switches listed, and compare scan tool PID reading to switch condition. If PID reading matches switch condition, go to next step. If PID reading does not match switch condition, perform appropriate SYSTEM TEST.

SWITCH MONITOR TEST

Switch & Condition

PID Reading

Go To

Vehicle Start (VST) Signal

Ignition On

OFF

Test A , Step 1)

Ignition Start

Test A , Step 1)

Power Steering Pressure Switch (PSP SW)

Engine Running, Steering In Neutral Position

OFF

Test FF , Step 1)

Engine Running, Steering Turned

Test FF , Step 1)

A/C Switch (AC SW)

Ignition On, A/C Off

OFF

Test KM , Step 1)

Ignition On, A/C On

Test KM , Step 1)

Park/Neutral Position Signal (PNP)

Ignition On, Gearshift Lever In "N" Or "P" Range

⁽¹⁾

Ignition On, Gearshift Lever Not In "N" Or "P" Range

OFF

⁽¹⁾

A/C Relay (ACR)

Engine Running, A/C Off

OFF

Test KM , Step 1)

Engine Running, A/C On

Test KM , Step 1)

Cooling Fan Relay (Low) (LFAN)

Engine Running, A/C Off

OFF

Test KF , Step 1)

Engine Running, A/C On

Test KF , Step 1)

⁽¹⁾	Perform TEST D: TRANSMISSION RANGE SENSOR under DIAGNOSTIC TESTS in 4F20E DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

2) Perform Intermittent Diagnostic Test

Check for intermittent faults. Perform TEST Z , step 1) under SYSTEM TESTS. Repair faults as necessary and retest system. If no faults are found, go to SYMPTOM DIAGNOSIS under SYMPTOMS in TROUBLE SHOOTING - NO CODES - VILLAGER article.