Control module and output signals

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC TROUBLE CODE P0600-P0688

SAE-DTC	DTC text	Corrective action
P0600	Serial Communication Link	Check terminal resistance for CAN-Bus. See TERMINAL RESISTANCE FOR CAN-BUS, CHECKING .
P0601	Internal Control Module Memory Check Sum Error	Replacing Engine Control Module (ECM)
P0602	Control Module Programming Error	Procedure to code Engine Control Module (ECM): Motronic Fuel Injection and Ignition (4-cylinder Turbo); See ENCODING II ENGINE CONTROL MODULE (ECM) .
P0604	Internal Control Module Random Access Memory (RAM) Error	Replacing Engine Control Module (ECM)
P0606	ECM/PCM Processor	Replacing Engine Control Module (ECM)
P0638	Throttle Actuator Control Range/Performance, Bank 1	Check Throttle Valve Control Module -J338-. See THROTTLE VALVE CONTROL MODULE -J338-, CHECKING . Check Throttle Position (TP) sensor. See THROTTLE POSITION (TP) SENSOR, CHECKING .
P0685	ECM/PCM Power Relay Control Circuit/Open	Check voltage supply for Engine Control Module (ECM). See VOLTAGE SUPPLY FOR ENGINE CONTROL MODULE (ECM), CHECKING . Check Motronic Engine Control Module (ECM) Power Supply Relay -J271- and activation. See CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION .
P0686	ECM/PCM Power Relay Control Circuit Low
P0687	ECM/PCM Power Relay Control Circuit High
P0688	ECM/PCM Power Relay Sense Circuit/Open