2004 Chevrolet Optra Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Temperature Versus Resistance

°C °F ECT Sensor IAT Sensor
OHMS
Temperature vs Resistance Values (Approximate)
100 212 177 187
90 194 241 246
80 176 332 327
70 158 467 441
60 140 667 603
50 122 973 837
45 113 1,188 991
40 104 1,459 1,180
35 95 1,802 1,412
30 86 2,238 1,700
25 77 2,796 2,055
20 68 3,520 2,500
15 59 4,450 3,055
10 50 5,670 3,760
5 41 7,280 4,651
0 32 9,420 5,800
-5 23 12,300 7,273
-10 14 16,180 9,200
-15 5 21,450 9,200
-20 -4 28,680 15,080
-30 -22 52,700 25,600
-40 -40 100,700 45,300
Factory Service Tools

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.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.