Drive Cycles

DRIVE CYCLES

OBD Drive Cycle

Description
The primary intention of the OBD Drive Cycle is to clear the DTC P1000 and to satisfy the specifications for SAE specification J1979. Each OBD monitor must run during the drive cycle.

If the drive cycle is completed and P1000 is not cleared, repeat the entire drive cycle. If a particular step is interrupted, simply repeat the drive mode. If the drive cycle is interrupted with a key-off, only drive modes that were incomplete must be run.

NOTICE: Strict observance of posted speed limits and attention to driving conditions are mandatory when proceeding through the drive cycle.

Rough road conditions may prevent certain steady state conditions and steady accelerations from validating the transmission- and load-related monitors.

Vehicles equipped with Power Take-Off (PTO) must have that system disengaged before the OBD drive cycle is initiated.

Drive Cycle Procedure:
1. Key on. Do not crank until the WAIT TO START light cycles, or at least 10 seconds, whichever is greater.
2. Start the engine. Idle in PARK or NEUTRAL for 40 seconds.
3. The following outlines the appropriate conditions for running certain OBD monitors that require the engine to be under load:
a. Accelerate steadily to third gear (M/T use fourth gear) and hold at 1500 rpm for 3 seconds. Accelerate steadily from 35 mph to 65 mph over approximately 15 seconds (M/T 11 seconds minimum).
b. Repeat Step 3a three times while maintaining the conditions in Step 3a.
c. Before proceeding, turn all accessories off and disengage tow/haul.
4. Before continuing, EOT must exceed 60°C (140°F).
5. Idle the vehicle for 20 seconds in PARK or NEUTRAL.
6. Key off.
7. Start the engine. Idle in PARK or NEUTRAL for 40 seconds.
8. Rerun Quick Test.

NOTE: If P1000 is present after running the drive cycle:
- Rerun Step 3a, being certain to maintain a minimum MFDES of 35 mg/stroke above 2,000 rpm for 11 seconds. Also, maintain a minimum MFDES of 30 mg/stroke above 2,800 rpm for at least 6 seconds.
- Rerun Step 8. MFDES must remain below 12 mg/stroke for 11 consecutive seconds.

OBD PID Data Monitor
The PID monitor for OBD offers real time evaluation of several emission-related parameters. Most of these are related to the HO2S for which the diesel has no equivalent. The only parameters that apply to 6.0L diesel applications are DTC CNT, MAP, MIL, RPM and VSS.

Accessing the PID Data Monitor
- Refer to the manufacturer manual for scan tool instructions.

OBD Pending DTCs
Pending DTCs are DTCs that have only set during one drive cycle and may not have set the MIL yet. These DTCs can be identified using the Retrieve Pending DTCs feature. Additionally, they will be found in the vehicle-specific mode RETRIEVE/CLEAR CONTINUOUS MEMORY DTCs from the instant the DTC is set.

This function will only report pending failures that have occurred during the present or previous drive cycle, but will not indicate single failures that happened on any two previous drive cycles.

Accessing the PID Data Monitor
- Refer to the manufacturer manual for scan tool instructions.