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.
1988 Mercedes Benz 560SLFACTORY OEM SERVICE PROCEDURE
Testing With On-Off Ratio Tester: Notes
NOTE:
On California models, the CIS-E control unit must first be programmed to read the On-Off ratio if On-Off Ratio Tester (KDJE-P 600
) is to be used.
- Connect Bosch Tester (KDJE-P600 ) to CIS-E diagnostic socket. All on-off ratio values are to be checked with engine running at idle speed and at normal operating temperature. See Fig 1 .
- The fixed on-off ratio indicates a possible malfunction. The TROUBLE SHOOTING and DIAGNOSTIC TESTING sections will help in diagnosing problems with the CIS-E fuel injection system. If a problem cannot be solved using these sections, see COMPONENT TESTING in this article.
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.
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.