Lambda Control System Quick-Test

On-Board Diagnostic Readout with On-Off Ratio Tester
Model Year 1987/88 Federal and California Vehicles

NOTE:
This test should be performed in case of engine performance related complaints e.g.: uneven idle, hesitation, etc.

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.

Special Tools





Equipment
Digital multimeter -- Available through the MBNA Standard Equipment Program.
^ Manufacturers: SUN DMM-5, Fluke model 23

Testing





- Connect test equipment as shown.
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 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: