Diagnostic Trouble Codes (DTCs)

Selecting Engine Diagnostics from the Vehicle Area screen brings up the following Engine Diagnostics Screen.

Diagnostic Trouble Codes (DTCs)

On selecting Diagnostic Trouble Codes, the PCM memory will be scanned and any recorded DTCs will be decoded and displayed.

The engine and transmission DTCs are integral to the On Board Diagnostics (OBD II) system and are fully described in the DB7 OBD II Diagnostics Manual.

Before attempting to clear the logged DTCs, record all logged DTCs for use in subsequent fault analysis.

All logged DTCs may be cleared by selecting the EEC-V EMS DTCs title. This will bring up the Clear (C) icon which may be selected and confirmed to clear all logged DTCs.

Note that on clearing all logged DTCs you will also clear the associated timers, counters and fault history files (and extinguish the engine management warning light for North American vehicles). The OBD II readines test status will also clear down and a P1000 (OBD II readiness test incomplete) trouble code will be set.. A full drive cycle (see DB7 OBD II Diagnostics Manual) must be completed to clear the P1000 code if required. The P1000 code will clear automatically after some miles of driving when all required tests have satisfactorily completed.

Caution: If a transmission code is logged in the PCM, the TCM DTCs must be cleared first and then clear the PCM DTCs. If the PCM DTCs are cleared without clearing the TCM, the TCM code will immediately reset in the PCM when power is restored.

Key On Engine Off (KOE0) and Key On Engine Running (KOER) On Demand Self Tests

Before either the KOEO or KOER test will run, the engine coolant temperature must be in excess of 80°C. Select and confirm either the KOEO or KOER test. If the coolant temperature is too low, the Pre Test Engine Warm Up screen will appear. Start the engine and run until coolant temperature is at 80+°C.

KOE0 Test

As coolant temperature rises through the 80°C level, the technician will be requested to turn the ignition off and then on again. The KOEO test will then commence. Static inputs to the PCM will be checked and any faults detected will be recorded and displayed as DTCs. If any DTCs other than P1000 are logged, go to the OBD II Diagnostics Manual and resolve the concern(s) using the OBD II diagnostic procedures.

KOER Test

If coolant temperature level is below 80°C, the technician will be prompted to start and run the engine until coolant temperature rises above 80°C. As the temperature passes the 80°C level, the KOER test will commence automatically.

If coolant temperature is above the 80°C level, the technician will be requested to start the engine. The KOER test will commence as the engine is started. Dynamic inputs to the PCM will be checked and any faults detected will be recorded and displayed as DTCs. If any DTCs other than P1000 are logged, go to the OBD II Diagnostics Manual and resolve the problem(s) using the OBD II diagnostic procedures.