Monitors, Trips, Drive Cycles and Readiness Codes
Readiness Code
=> [ Readiness Code, Reading ]
=> [ Readiness Code, Generating ]
Readiness Code, Reading
Function
The readiness code is an 8 digit number block that indicates the results of an exhaust related On Board Diagnostic (OBD).
If a diagnostic for a system has run through successfully, the respective digit of the number block is set from 1 to 0.
On Board Diagnostics are performed at regular intervals during normal vehicle operation. After repairing an exhaust relevant system, the readiness code should be generated via a road test to ensure that these systems are working according to specifications. If a malfunction is recognized during diagnostic, it is stored in DTC memory.
The readiness code is erased every time DTC memory is erased or when voltage supply is interrupted. DTC memory should therefore only be erased when there are DTCs stored.
Prerequisites
• There must not be any DTCs stored in DTC memory => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 3: Check DTC memory.
• Coolant temperature must be at least 80° C => [ Diagnostic Mode 01 - Read Current System Data ] Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
Procedure
- Connect diagnostic tester.
- Start engine and let run at idle.
- Under address word 33, select "Diagnostic mode 1: Checking measured values."
- Select desired measuring value "PID 01".
- Observe right 8-digit number block:
If all diagnostics have run through successfully, the following specified value 8-digit number block must appear.
• Specified value: displaying 00000000.
Evaluation PID 01: System status-information (right 8-digit number block:)
If a 1 is displayed instead of a 0 in the 8-digit number block:
- Generate readiness code => [ Readiness Code, Generating ].
Readiness Code, Generating
Prerequisites
• The respective fuses of the Motronic fuel injection and ignition system must be OK:
• Battery voltage must be at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster must be switched off.
• If vehicle is equipped with an A/C system, it must be switched off.
• Ground (GND) connections between engine and chassis must be OK.
• There must not be any DTCs stored in DTC memory => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 3: Check DTC memory.
Let vehicle cool off with the ignition switched off until the following conditions are met:
• Intake air temperature 10 to 50° C => [ Diagnostic Mode 01 - Read Current System Data ] Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measured values; PID 15
• Coolant temperature approx. intake air temperature (10 to 50° C) => [ Diagnostic Mode 01 - Read Current System Data ] Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measured values; PID 5
Procedure
- Connect diagnostic tester.
- Start engine and let run at idle for at least 15 minutes.
Observe safety precautions that apply to road tests, refer to Repair Information.
- Perform a 15 minute road test in the highest gear or in the highest driving mode on a level driving surface.
• Engine speed approx. 1800 to 2200 RPM => [ Diagnostic Mode 01 - Read Current System Data ] Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measuring values; PID 12, engine rotations per minute (RPM)
• Vehicle speed constant 90 km/h => [ Diagnostic Mode 01 - Read Current System Data ] Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measuring values; PID 13, Vehicle speed
- Do not switch off engine and let run at idle for at least 3 minutes.
Secondary Air Injection (AIR) system will be checked during this idle phase.
- Switch off engine for at least 30 minutes so that coolant temperature can drop to about a minimum of 10° C.
- Start engine and let run at least 2 minutes at idle.
Engine coolant temperature sensor will be checked during this idle phase.
Observe the safety precautions that apply to road tests, refer to Repair Information.
- Read readiness code => [ Readiness Code, Reading ].