Mercedes Benz C 43 AMG Technical Service Bulletin # P-07_07-34 Date: 030724

Mercedes Benz C 43 AMG Technical Service Bulletin # P-07_07-34 Date: 030724

Engine Controls - MIL ON/Multiple DTC's Set

Date: July 24, 2003

Order No.: P-B-07.07/34

Supersedes:

Group: 07

SUBJECT:

Model 129.068

Model 170.465

143

Model 202.029/033

Model 203.061/064/081/084/264/281/284/764

Model 208.365/370/374/465/470/474

Model 209.365/375/465/475

Model 210.065/070/074/082/083/265/282

Model 211.065/070

Model 215.373/375

Model 220.070/170/173/175/183/184

Model 230.475

Air Mass Sensor Replacement Due to Codes P2004, P0170 and P0173

If you receive customer reports in the above model vehicles of the check engine light coming on and codes P2004, P0170 and P0173 are stored,

prior to replacing the air mass sensor refer to the following procedure.

Error Code P2004 splits into four subcodes (Figure 1) to provide more detailed information regarding the source of the fault.

Test voltage supply 5V (Figure 2) and 12V (Figure 3) of component B215 (hot film MAF sensor).

If test is OK, proceed to step 2. If test failed, perform the following:

- Check 12V voltage supply from ME control unit.

- Check connection point for ground of ME control unit.

- Check wiring harness and Z-connection (Z7136) from the air mass sensor.

- Check for other error codes from components (pressure sensor, oil quality sensor, etc.) which receives 5V voltage supply from the ME control

unit on the same line.

Error Code P2016-[1], P2017-[1], P2018-[1] (P0170) and P2085-[1], P2086-[1], P2087-[1] (P0173)

144

Step 2 - Test signal voltage of component B215 (hot film MAF sensor) by means of actual value (Figure 4).

Check for the voltage value of the air mass sensor with the ignition ON (engine not running).

Voltage range must be between [0.980 - 1.030V].

If the air mass sensor voltage is out of range [0.980 - 1.030V], replace the air mass sensor.

If the air mass sensor voltage value is in the specified range [0.980 - 1.030V], check for any air leaks in the air intake system.

In particular on models 170, 203, 209, 211, 215, 220 and 230, check for proper installation of the air mass sensor to intake manifold (Figure 5 and 6

are examples of improper installation)

If necessary, correct the installation of the air mass sensor to the intake manifold (Figure 7 and 8). Do not replace the air mass sensor.

Note:

Before replacing the air mass sensor, check for sand and dirt particles in the clean side (between air filter and engine) of the air intake system and

clean if necessary. Check complete air intake system with air cleaner and repair as necessary.

Return air mass sensor must be accompanied by air mass sensor voltage screen printout (Figure 4) and OBD-Code freeze frame data. Returned air

mass sensor with voltage range between [0.980 - 1.030 V] or without this print outs will be debited back to the dealer as of repair date July 24, 2003.