Campaign - CIS-E Control Unit False Fault Code 16
90mercedes05 April 1990TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS
CAMPAIGN NO. 90-0442 CIS-E CONTROL UNIT WITH MALFUNCTION CODE 16 CALIFORNIA VERSION VEHICLES MODEL YEAR 1990 WITH ENGINE 103 MODEL 124, 126 AND 201
Enclosed is a sample copy of a letter which all affected vehicle owners will receive in the near future.
This campaign is being initiated because field inspection of certain 1990 models has revealed a potential for a false triggering of the CHECK ENGINE light on the dash.
On vehicles within the below listed serial number range, it is possible for the malfunction code 16 (ESR) to be stored in the CIS-E control unit (CHECK ENGINE light comes on) even if there is no fault in any of the emission system and/or components.
Figure 1:
Effective Serial Number
Model Chassis End Number
124 B 065159 B 140136
F 122382 F 128655
126 A 499132
A 519940
201 F 649246
F 695025
The control unit must be replaced on these vehicles.
Note: Only model year 1990 vehicles With CIS-E control units up to Bosch Production oode 950 (arrow, Figure 1) are affected.
A) Vehicles in which the CHECK ENGINE light does not come on
On these vehicles, the CIS-E control unit is to be replaced without going through the test steps mentioned in paragraph "B".
B) Vehicles in which the CHECK ENGINE light comes on
On these vehicles, the malfunction codes must be read with the impulse counter prior to replacing the control unit. If malfunction code 16 is stored in memory, the test steps 21.0 to 22.2 in the model year 1990 introduction manual must be carried out, to assure that there are no malfunctions in the emission system components.
Parts Information
Model Part Name Part Number
124.026 CIS-E control unit
201.029 " 011 545 05 32/05
124.030/090 CIS-E control unit
230/290 " 011 545 01 32/05
126.024/025 " 011 545 03 32/05
Return of CIS-E Control Units
Control units should be returned to MBNA WARRANTY INSPECTION, 1 Glenview Rd. Montvale, NJ 07645, with the California Emission parts Return Envelope, as quickly as possible. DO NOT WAIT FOR PARTS RETURN LIST.
Warranty Claim Submission Information
Campaign Claim Type 3 Campaign # 90-0442 Damge Code 5494008 CIS-E Control Unit Repair Codes:
Repair Code 10 Inspect 0.2 hr.
Repair Code 11 CIS-E Control Inspect and Replace 0.3 hr. | 25/45/82/83
(without impulse readout and Code 16) | 88/74/75
Repair Code 12 CIS-E Control Inspect and Replaoe 0.5 hr. | 25/45/82/83
(with impulse readout and Code 16) | 88/74/75
April 27, 1990
Dear Mercedes-Benz Owner:
Field inspections of 1990 models 190E 2.6, 300E 2.6, 300E, 300E4M, 300TE, 300TE4M, 300SE and 300SEL sold in California and other Western states have revealed a potential for a false diagnostic signal triggering of the Malfunction Indicator Light ("CHECK ENGINE" Light) on the dash.
This does not affect the operation of the vehicle, but may cause unnecessary concern for the driver when the indicator light is lit.
To correct this potential problem, the Emission Control System will be checked and the Electronic Control Unit will be exchanged at no cost to you.
We urge you to contact your local authorized Mercedes-Benz dealer for an appointment. Parts will be available as of April 1990, and your dealer will order the part as soon as you make an appointment with him.
Time involved
Check Emission Control System and Replace ECU 0.5 Hours Replace ECU only 0.3 Hours