LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2002 >> Corolla S, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 47 (Automatic Transmission Diagnosis - U340E & U341E) >> Diagnostic Tests >> DTC P1520: Stoplight Switch Signal Malfunction >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Toyota ECHO, 2002 Toyota Celica, 2001 Toyota ECHO, and 2001 Toyota Celica. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check stoplights. If stoplights do not function properly, repair as necessary and retest system. If stoplights function properly, go to next step.
  2. Turn ignition switch to ON position. Using a DVOM, measure voltage between ground and appropriate ECM connector at terminal No. 6 (STP). See WIRING DIAGRAMS . With brake pedal depressed, voltage should be 7.5-14.0 volts. With brake pedal released, voltage should be less than 1.5 volt.
  3. If voltage is not as specified, check brakelight switch. See BRAKELIGHT SWITCH  under COMPONENT TESTS. If brakelight switch is okay, check circuit between brakelight switch and ECM. If circuit is okay, replace ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. If voltage is as specified, check wiring harness and connectors. Problem is intermittent.
scientia non olet · About LEMON Manuals