EGR Valve - Testing
TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERSDATE: May 1991
REF.NO. MBNA 14/6
SUBJECT:
ENGINES 103 AND 104 TESTING OF EGR VALVE
On all vehicles manufactured within the serial number range specified, the EGR valves must be checked on the vehicle's next workshop visit as described below:
Begin testing the EGR valve by checking the CIS-E on-board diagnostics for a stored malfunction code 16. A vacuum and function test of the EGR valve must be performed if code 16 is displayed. In the case of California version vehicles, the "Check Engine" light will be illuminated as a result of malfunction code 16. On both Federal and California version vehicles, the failure code must be erased from the on-board diagnostics memory before the vehicle is returned to the customer.
Note:
If the diaphragm of the EGR valve leaks vacuum, the EGR valve must be replaced. When checking the EGR valve diaphragm for leaks, it is important that its function also be verified. This requires applying vacuum to the EGR valve, then listening for a "popping" sound when the vacuum is quickly disconnected.
Apply a red paint dot in a clearly visible location to all tested or replaced EGR valves.
For complete test procedures of the EGR system for both impulse readout and component testing,
see: Model Year 1990 Introduction Manual
Models 124, 126, 201
Engine 103 Group 07.3
Test steps 21.0 to 21.1, and 22.0 to 22.3
or: Diagnostic Manual Model 129
Engine 104, Section 1.1.3
Test steps 33.0 to 33.1, and 34.0 to 34.3
Parts Information
Part Name Part Number
EGR valve 001 140 48 60
In Case of Warranty:
If testing of the complete EGR system is required, this additional repair procedure should be submitted on a separate warranty claim with detailed explanation.
Operation: Checking impulse readout of CIS-E control unit for malfunction code 16; vacuum and function test of EGR valve; resetting of memory:
Operation: Replacement of EGR valve (after testing)