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On-Off Ratio Test

ON-OFF RATIO TEST, IGNITION: ON

On-Off Ratio % See
0 Fig 1
10 Fig 1
20 Fig 1
30 Fig 1
40 -
50 Fig 1
60 Fig 1
70 Fig 1
80 Fig 1
90 Fig 1
ON-OFF RATIO TEST, ENGINE: AT CTP (IDLE)

On-Off Ratio % Possible Cause See
0 Short circuit to battery + in wire to data link connector (X11/4), socket 3. Fig 4
10 CTP (idle) recognition applied constantly. Fig 2
20 Output of fuel injectors or more fuel injectors have open circuit. Fig 2
30 ECT sensor (B11/2). Fig 2
40 Hot wire MAF sensor (B2/2). Fig 2
50 O2S 1 - before TWC (G3/2) not operational or defective, open circuit. Fig 2
60 CMP sensor (L5/1). Fig 2
70 TN-signal (RPM signal). Fig 2
80 CAN-data exchange defective. Fig 2
90 Vehicle Speed Signal (VSS). Fig 2
95 Deceleration Shut-Off Active. Fig 2
100 No voltage at LH-SFI control module (N3/1). Fig 2
LH-SFI CONTROL MODULE DTC READOUT

DTC Possible Cause See
1 No malfunction in system. Fig 3
2 ECT sensor (B11/2) sensor circuit 1, open/short circuit. Fig 3
3 ECT sensor (B11/2) sensor circuit 2, open/short circuit. Fig 3
4 Voltage at hot wire MAF sensor (B2/2) insufficient of too high, or open circuit in ground wire at hot wire MAF sensor. Fig 3
5 Not Used -
6 Not Used -
7 TN-signal (RPM signal) incorrect or open/short circuit. Fig 3
8 CMP sensor (L5/1) signal, open/short circuit. Fig 3
9 Starter signal (circuit 50) missing, open/short circuit. Fig 3
10 CTP (idle) recognition from EA/CC/ISC control module (N4/1) or CC/ISC control module (N4/3), short circuit Fig 3
11 Secondary air injection system, open/short circuit. Fig 3
12 Burn off control for hot wire MAF sensor, open/short circuit. Fig 4
13 IAT sensor (B17/7), open/short circuit. Fig 4
14 Not Used -
15 Not Used -
16 EGR switchover valve (Y27), open/short circuit. Fig 4
17 No CAN data transmission with EA/CC/ISC control module (N4/1) or CC/ISC control module (N4/3). Fig 4
18 No CAN transmission with DI control module (N1/3) Fig 4
19 Not Used -
20 No CAN data transmission from LH-SFI control module (N3/1). Fig 4
21 O2S 1 - before TWC (G3/2), open/short circuit. Fig 4
22 O2S 1 heater, open/short circuit. Fig 5
23 Purge control valve (Y58/1), open/short circuit. Fig 5 28
24 Left adjustable camshaft timing solenoid (Y49/2), open/short circuit. Fig 5
25 Adjustable camshaft timing solenoid, engine 104 (Y49) or right adjustable timing solenoid, engine 119 (Y49/2), open/short circuit. Fig 5
26 Upshift delay switchover valve (Y3/3), open/short circuit. Fig 5
27 Injectors (Y62), open/short circuit. Fig 5
28 LH-SFI control module coding, open circuit. Fig 5
29 1GR start relay module (K29/1), open/short circuit. Fig 5
Fig 1: Diagnostic Trouble Code Definitions - On-Off Ratio Test, Ignition: ON
G00221611Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Fig 2: Diagnostic Trouble Code Definitions - On-Off Ratio Test, Engine: At CTP (Idle)
G00221612Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Fig 3: Diagnostic Trouble Code Definitions - LH-SFI Control Module DTC Readout (1 Of 3)
G00221613Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Fig 4: Diagnostic Trouble Code Definitions - LH-SFI Control Module DTC Readout (2 Of 3)
G00221614Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Fig 5: Diagnostic Trouble Code Definitions - LH-SFI Control Module DTC Readout (3 Of 3)
G00221615Courtesy of MERCEDES-BENZ OF NORTH AMERICA.