Preparation for DTC Readout Diagnostic module (OBD II, N59/1) uses two different plug connectors for DTC readout: a) 16-pole diagnostic module (OBD II) generic scan tool connector (X11/22) using a generic scan tool (see connection diagram), b) 38-pole data link connector (X11/4) using the HHT (see section 0). DTC readout using the impulse counter scan tool or via the LED pushbutton switch has been eliminated. During DTC readout, the CHECK ENGINE MIL stays on continuously. Notes Regarding Diagnostic Trouble Codes (DTC's) The retained diagnostic trouble code (DTC) memory feature of the diagnostic module has been replaced with DTC memory which is cleared after disconnecting the vehicle's battery. Notes Regarding DTC Readout Using Generic Scan Tool In case of DTC and , the exact cause of the fault in oxygen sensor 1 (O2S 1) can be read via "MODE 5" with the generic scan tool. To do so, the following codes must be entered in the generic scan tool: DTC : Code JD 4A HEX DTC : Code JD 7E HEX

DTC	Possible cause	Test step/Remedy 1)
	O2S 1 (before TWC) (G3/2) circuit high voltage	23 4.0
	O2S 1 (before TWC) (G3/2) circuit no activity detected	23 4.0
	O2S 1 (before TWC) (G3/2) circuit low voltage	23 4.0
	O2S 1 (before TWC) (G3/2) circuit short circuit	23 4.0
	O2S 1 (before TWC) (G3/2) circuit slow response	Damage to TWC 23 4.0
	O2S 1 (before TWC) (G3/2) heater circuit malfunction	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	O2S 1 (before TWC) (G3/2) circuit "rich" stop	Unmetered air, Damage to TWC or O2S
	O2S 2 (after TWC) (G3/1) circuit high voltage	23 5.0
	O2S 2 (after TWC) (G3/1) heater circuit malfunction	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	O2S 2 (after TWC) (G3/1) circuit short circuit	23 5.0
	O2S 2 (after TWC) (G3/1) operating condition	23 5.0
	Secondary air injection (AIR) system switching valve/circuit malfunction Model 129, 140: AIR pump switchover valve (Y32) and electromagnetic AIR pump clutch (Y33) Model 210: AIR pump switchover valve (Y32) and AIR relay module (K17)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Secondary air injection system incorrect flow detected	Hose lines, AIR pump, AIR shut-off valve
	Electrical activation of the EGR switchover valve (Y27)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Exhaust gas recirculation flow malfunction	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1 23 38.0 - 40.0 ,
	Idle control system RPM higher than expected	Test EA/CC, see DM, Engines, Vol. 3, section 6 and/or 7
	Idle control system malfunction	Test EA/CC, see DM, Engines, Vol. 3, section 6 and/or 7
	TWC protection single cylinder misfire (Single cylinder ignition misfire within 200 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	TWC protection random cylinder misfire (Random cylinder ignition misfire within 200 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	FTP standards single cylinder misfire (Single cylinder ignition misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	FTP standards random cylinder misfire (Random cylinder ignition misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	I/M test single cylinder misfire (Single cylinder ignition misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	I/M test random cylinder misfire (Random cylinder ignition misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Catalyst system efficiency below threshold	Catalytic converter (physical damage)
	Electrical activation of adjustable camshaft timing solenoid (Y49)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1 ,
	Adjustable camshaft timing solenoid (Y49) without function (Logic chain)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1 23 32.0 ,
	Injector circuit malfunction	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Short term fuel trim (self-adaptation of fuel mixture)	Unmetered air, Injectors (Y62), Diaphragm pressure regulator, Hot film mass air flow sensor (B2/5), Engine wear (reset self-adaptation after repairs, see DM, Engines, Vol. 2, section 1.1 )
	Fuel trim malfunction (self-adaptation of fuel mixture)	Unmetered air, Injectors (Y62), Diaphragm pressure regulator, Hot film mass air flow sensor (B2/5), Engine wear (reset self-adaptation after repairs, see DM, Engines, Vol. 2, section 1.1 )
	Evaporative emission control system (EVAP) purge control valve circuit malfunction (Purge control valve [Y58/1])	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Electrical activation of purge flow switchover valve (Y27/6)	23 8.0
	EVAP without function (logic chain)	23 9.0
	Pressure switchover without function (logic chain)	23 10.0
	Electrical activation of upshift delay switchover valve (Y3/3)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Transmission upshift delay switchover valve (Y3/3) without function (Logic chain)	Upshift delay switchover valve (Y3/3), A/T control pressure cable adjustment (see SMS)
	TWC protection single cylinder misfire (Single cylinder combustion misfire within 200 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	TWC protection random cylinder misfire (Random cylinder combustion misfire within 200 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	FTP standards single cylinder misfire (Single cylinder combustion misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	FTP standards random cylinder misfire (Random cylinder combustion misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	I/M test single cylinder misfire (Single cylinder combustion misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	I/M test random cylinder misfire (Random cylinder combustion misfire within 1000 engine revolutions)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	CMP sensor (L5/1) or camshaft Hall-effect sensor (B6/1) monitoring signal from engine control module (N3/4)	23 7.0
	Engine speed signal TNA from diagnostic module (OBD II) not received	23 6.0
	Electrical activation of resonance intake manifold switchover valve (Y22/6)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Engine coolant temperature circuit range/performance problem (ECT sensor [B11/3])	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Insufficient coolant temperature for closed loop fuel control	Engine coolant temperature sensor (B11/3)
	Intake air temperature circuit range/performance problem (IAT sensor [B17])	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1 , 1.2
	Mass or volume air flow circuit range/performance problem (Hot film MAF sensor [B2/5])	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	CKP sensor circuit malfunction	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	CKP sensor signal: Magnet coding on segment	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Engine speed signal TNA not transmitted from engine control module	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Full load information: Load implausible	Test EA/CC, see DM, Engines, Vol. 3, section 6 and/or 7
	Full load information: Throttle valve position implausible	Test EA/CC, see DM, Engines, Vol. 3, section 6 and/or 7
	CTP information: Air mass implausible	Test EA/CC, see DM, Engines, Vol. 3, section 6 and/or 7
	Serial communication link malfunction (CAN)	23 13.0
	Vehicle speed signal implausible	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Vehicle speed implausible	Engine control module (N3/4)
	CMP sensor (L5/1) or camshaft Hall-effect sensor (B6/1)	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Manifold absolute pressure implausible	23 11.0
	Knock sensor 1; sensor signal	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Knock sensor 1; circuit range/performance	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Knock sensor 1; control range end stop	Test HFM-SFI, see DM, Engines, Vol. 2, section 1.1
	Diagnostic module (N59/1) voltage supply from circuit 30 too low	23 1.0

1) Observe Preparation for Test, see 22 .