Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Circuit Check
The diagnostic circuit check will identify a problem created by an Electronic Engine Control System (EECS) malfunction. It is the starting point for diagnosis. This directs you to the next logical step in diagnosing a complaint.
After completing diagnostic circuit check and finding on-board diagnostics functioning properly with no trouble codes displayed, use SCAN DATA table for comparison. The typical values are an average of display values recorded from a properly operating vehicle, and are intended to represent a normal system display.
| Scan Position | (1) Data Value | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| A/C Clutch | Off | |||||||||
| A/C Request | No | |||||||||
| Base Pulse Width (BPW) | .8-3.0 Milliseconds | |||||||||
| Battery | 13.5-14.5 Volts | |||||||||
| Block Learn Cell | 0 | |||||||||
| Block Learn Enable | No | |||||||||
| Block Learn Memory (BLM) | 118-138 Counts | |||||||||
| Coolant Temperature | 185-221°F (85-105°C) | |||||||||
| Desired RPM | ECM Idle Command | |||||||||
| EGR Solenoid | Off | |||||||||
| EGR Temp. Signal | 0-5 Volts | |||||||||
| Engine RPM | ||||||||||
| A/T | 890-990 RPM | |||||||||
| M/T | 800-900 RPM | |||||||||
| IAC | 1-50 Counts | |||||||||
| Idle Throttle | No | |||||||||
| Integrator (INT) | 110-145 Counts | |||||||||
| MAP | (2) .5-2.0 Volts | |||||||||
| MAT Temperature | (3) 50-194°F (10-90°C) | |||||||||
| Open/Closed Loop | Closed Loop (Open w/Extended Idle) | |||||||||
| O2 Sensor | (4) 100-900 Millivolts | |||||||||
| Park/Neutral Switch | P/N | |||||||||
| Power Steering Switch | Normal | |||||||||
| Shift Light (M/T) | Off | |||||||||
| Spark Advance | Varies | |||||||||
| Throttle Angle (%) | 0 | |||||||||
| TPS | .4-1.25 Volts | |||||||||
| Vehicle Speed | 0 | |||||||||
|
||||||||||
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.