With On-Off Ratio Tester

NOTE: This test should be performed in case of engine performance related complaints e.g.: uneven idle, hesitation, etc. Prior to performing this test, ensure that the engine is at operating temperature and that there are no intake/vacuum leaks present. In Model Year 1988 California version vehicles, the CIS-E control unit must first be programmed to read the on-off ratio. A constant on-off ratio readout indicates that test steps 1 to 4 must first be performed according to the troubleshooting chart on the following pages.

Special Tools:

Equipment
Digital multimeter -- SUN DMM-5, Fluke model 23

- Connect test equipment according to image below.





01 Connector, CIS-E control unit
02 Test cable
03 Multimeter
04 Socket box
012 On-off ratio tester
N3 CIS-E control unit
X11 Diagnostic socket

Altitude Correction Capsule Table:

Coolant Temperature Sensor Chart:

Icon Legend For Trouble Shooting Charts:

Fixed On-Off Ratio -% Test Step 1:

Fixed On-Off Ratio -% Test Step 2:

Fixed On-Off Ratio - % Test Step 3:

Fixed On-Off Ratio - % Test Step 4:

Fixed On-Off Ratio 0% Test Step 5:

Fixed On-Off Ratio 10% Test Step 6:

Fixed On-Off Ratio 20% Test Step 7:

Fixed On-Off Ratio 30% Test Step 8:

Fixed On-Off Ratio 30% Test Step 8 (continued):

Fixed On-Off Ratio - 40% Test Step 9:

Fixed On-Off Ratio 50% Test Step 10:

Fixed On-Off Ratio 60%:

Fixed On-Off Ratio 70% Test Step 11:

Fixed On-Off Ratio 80% Test Step 12:

Fixed On-Off Ratio 90%:

Fixed On-Off Ratio 100% and Idle Speed too High Test Step 13: