These suggestions and solutions for technical problems come from service bulletins and other technical information published by Mercedes-Benz, selected and rewritten for independent repair shops.

Electronic Ignition Switch DTC B1000

Model 203

Due to an error in the DTC software, it is possible that the Diagnostic Trouble Code (DTC) B1000 may be saved in the Electronic Ignition Switch (EIS, N73). If this fault is present, but not current, the DTC may be ignored and the DTC memory erased. Do not replace the EIS for this condition.

Hard Starting, Won’t Run, or Poor Performance (possible DTC and inaccurate fuel level reading)

All 2001 C-Class

There’s a good chance that what’s happening here is the fuel pump check valve binding in the open position resulting in a reduction of fuel flow to the engine and to the fuel transfer pump in the fuel tank (i.e. no fuel transfer from one side of the fuel tank to the other).  Possible DTCs are P201B – 016 to 128, and P201C – 016 to 128.

Replace the fuel pump, Part Number 203 470 1394, production date 00T277 (277th day of 2000) or later.

Harmonic Balancer Trouble

1998 through 2000 Models 163, 202, 208 & 210 with 112 engine

Models 129, 163, 202, 208, 210, 215 & 220 with 113 engine, & 2001 Model 170 with 112 engine

MBUSA has determined that the harmonic balancer pulley in the above vehicles may, depending upon use and under-hood temperatures, deteriorate to the point of affecting performance and drivability, preceded by driver warnings such as noticeable engine vibration. Approximately 368,836 vehicles are affected.

First, check the part number of the balancer. ONLY these two part numbers require replacement:

• A112 035 00 00
• A112 035 06 00

Refer to the proper WIS procedures, such as AR61.20-P-1105GH, AR20.40-P-5660C, AR13.22-P-1202B, WF58.50-P-0330-02A, GF03.30-P-1600-01C, AR20.40-P-5000GH, etc.

NOTE: Torque the harmonic balancer pulley bolt in two stages:  First, to 200 Nm, then turn bolt an additional 95 degrees of rotation.

MILs Illuminated Only Briefly After Ignition Switched On

Models 202 and 210

If certain Malfunction Indicator Lamps (MILs) and other warning lamps in the instrument cluster (A1) light only briefly after switching the ignition ON (bulb check), this is an indication that the connection between the instrument cluster and the generator (G2, a.k.a. alternator) circuit 61 (D+) is open. The generator warning lamp does not come on for this condition. In these cases, check the wiring between the generator and the instrument cluster for an open circuit, as well as the generator itself. Correction for this condition DOES NOT require instrument cluster replacement.