DR-29 Checking Sensor Calibration

This test must be performed with engine cold. If drive complaint is with the engine warm, proceed to Test 30.
1. Switch diagnostic read-out tool to ``Read Sensor Values.''
2. Start the engine, then select ``Coolant Temperature'' test.
3. If reading is not within 10°F of ambient temperature, replace coolant sensor, then perform Test 37.
4. If reading is within 10°F of ambient temperature, turn ignition switch to the Off position.
5. Check for damaged or misadjusted throttle cables that would prevent idle return. Repair or adjust as needed.
6. Turn ignition switch to the On position, then switch diagnostic read-out tool to ``Read Sensor Voltages,'' and select ``Throttle Position.''
7. If reading is greater than 1.5 volts at idle, replace throttle position sensor, then proceed to Test 38.
8. If reading is 1.5 volts or less at idle, move the throttle to wide open position while watching the voltage reading.
9. If change in voltage is not smooth, replace throttle position sensor, then proceed to Test 38.
10. If change in voltage is smooth and wide open throttle position voltage is not at least 3.5 volts, replace throttle position sensor, then proceed to Test 38.
11. If wide open throttle position voltage is at least 3.5 volts, start the engine, then slowly increase engine speed to 2000 RPM.
12. If voltage reading did not increase, replace throttle position sensor, then proceed to Test 38.
13. If voltage reading did increase, allow the engine idle and select diagnostic read-out tool to ``Minimum Throttle.''
14. If voltage reading is greater than 1.5 volts, replace throttle position sensor, then proceed to Test 38.
15. If voltage reading is not as specified, turn ignition switch to the Off position.
16. Using a tee fitting, install a vacuum gauge to the MAP sensor vacuum line.
17. Start the engine, then switch the diagnostic read-out tool to ``Read Sensor Values'' and select ``Map Gauge Reading'' test.
18. Compare vacuum gauge to diagnostic read-out tool readings. If readings are within one inch of each other, proceed to step 19. If readings are not within one inch of each other, proceed as follows:
a. Turn the ignition switch to the Off position, then disconnect the vacuum gauge and map sensor vacuum hose.
b. Connect a vacuum pump to the MAP sensor, then turn ignition switch to the On position.
c. Select diagnostic read-out tool to ``Map Sensor Voltage'' test, then using the vacuum pump, apply 5 inches of vacuum to the MAP sensor and record voltage reading.
d. Slowly apply 20 inches of vacuum to the MAP sensor, if voltage decrease is erratic, replace MAP sensor, then proceed to Test 38.
e. If voltage decrease is not erratic, subtract second voltage reading from first reading.
f. If voltage calculation is between 2.3 and 2.9 volts, repair restriction in vacuum line to map sensor, then proceed to Test 38.
g. If voltage calculation is not as specified, replace MAP sensor, then proceed to Test 38.
19. With the engine cold, switch diagnostic read-out tool to ``Read Sensor Voltages'' then select ``T/Body Temp Sensor'' test.
20. Start engine. If voltage does not read between 4 and 5 volts, replace throttle body temperature sensor, then proceed to Test 38.
21. If voltage reads between 4 and 5 volts, remove and check spark plugs for fouling. Clean as needed, then reinstall spark plugs.
22. With engine cold, disconnect air cleaner snorkel fresh air duct. Air temperature should be below 76°F at the air cleaner temperature sensor.
23. Disconnect vacuum supply hose, then connect a vacuum pump and apply 15 inches of vacuum to the air cleaner temperature sensor.
24. If heat air door opens, then temperature sensor bleeds off vacuum until the door closes, proceed to test 31.
25. If heat air door remains open, proceed to step 29.
26. If heat air door does not open, disconnect vacuum hose between heat air door and temperature sensor.
27. If heat door opens, replace air temperature sensor in air cleaner, then proceed to Test 38.
28. If heat door does not open, repair sticking door, then proceed to Test 38.
29. Disconnect air temperature sensor second vacuum hose and apply 10 inches of vacuum.
30. If heat air door closes, replace air temperature sensor, then proceed to Test 38.
31. If heat air door does not close, repair or replace door as needed, then proceed to Test 38.