SYSTEM DESCRIPTION
The PCM monitors engine operation. It also contains a self-diagnostic system which stores Diagnostic Trouble Codes (DTCs) and compares them to On-Board Diagnostics II (OBD-II) standards.
The goal of OBD-II regulation is to provide vehicle with an on-board diagnostic system that is capable of continuously monitoring the efficiency of emission control systems, and to improve diagnosis and repair when system failures occur.
The Federal Test Procedure (FTP) sets maximum allowable emission standards. A Malfunction Indicator Light (MIL) must illuminate if a system or component either fails or deteriorates to a point where the vehicles emissions could rise to greater than 1 1/2 times FTP standards.
DTCs may only be retrieved using an On-Board Diagnostic (OBD-II) scan tool. TECH II scan tool is recommended by manufacturer. Other suitable aftermarket scan tools are available.
Description
The On-Board Diagnostic II (OBD-II) System Check is the starting point for any driveability complaint diagnosis. The OBD-II system check is an organized approach to identifying problems created by an electronic engine control system malfunction. Before any DTC(s) are retrieved, perform a visual underhood inspection, checking battery and grounds for clean and tight connections. Check for poor connections or damage to wiring harness and electrical connectors. Check for corroded terminals or corrosion buildup on any connection. Repair as necessary.
Use of TECH II scan tool or equivalent is required to perform On-Board Diagnostic II System Check.
Note. To identify component terminals and wire colors referenced in testing, see WIRING DIAGRAMS article.
Test Description
The numbers below refer to the step numbers in the diagnostic procedures.
- 2 Visually and physically inspect throttle valve conditions.
- 3 Visually and physically inspect accelerator pedal conditions.
- 6 Check throttle valve and throttle valve motor resistance. Check TPS resistance. See «THROTTLE POSITION SENSOR»(ref-97343-S20089060942002081300000) table. THROTTLE POSITION SENSOR TPS No.: Measure Between Pins (Wire Color) Specification (Ohms) Throttle Position Sensor No. 1 No. 1 (Green) & No. 5 (Red) 1000-7000 No. 1 (Green) & No. 6 (Blue) (1) Throttle Position Sensor No. 2 No. 4 (Green/White) & No. 8 (Red/White) 1000-7000 No. 4 (Green/White) & No. 7 (Blue/White) (1) (1) Resistance should change from .3-100 ohms as throttle is moved from closed throttle to wide open throttle.
- 7 Check APS resistance. See «ACCELERATOR POSITION SENSOR»(ref-97343-S21113569092002081300000) table. ACCELERATOR POSITION SENSOR APS No.: Measure Between Pins (Wire Color) Specification (Ohms) APS No. 1 No. 10 (Black) & No. 4 (Red) 4-6 No. 4 (Red) & No. 5 (White) (1) APS No. 2 No. 3 (Blue) & No. 8 (Green) 4-6 No. 3 (Blue) & No. 9 (Yellow) (1) APS No. 3 No. 1 (Orange) & No. 7 (Orange/Blue) 4-6 No. 6 (Blue/Green) & No. 7 (Orange/Blue) (1) (1) Resistance should change smoothly and steadily as accelerator pedal is pressed.
- 9 Software detected ETC system error.
- 10 Software detected ETC system error.