Quick Test Description/Operation

Quick Test is divided into three specialized tests:
1. Key ON Engine OFF (KOEO) Self-Test
2. Key ON Engine Running (KOER) Self-Test
3. Continuous Memory Diagnostic Trouble Code (DTC) Access.

Quick Test checks the integrity and function of the Electronic Engine Control (EEC) System and outputs the test results upon demand. Quick Test also provides a quick end check of the powertrain control system and is usually performed at the start of each diagnostic procedure. It is also performed at the end of most pinpoint tests for verification of repair and to make sure no other faults were incurred while servicing a previous fault.

System Pass
A system pass occurs when Quick Test is performed and DTCs are not output and a scan tool communication concern does not exist. System pass means that hardware monitored by the Powertrain Control Module (PCM) is functioning within normal operating limits.

Key ON Engine OFF Self-Test
Key ON Engine OFF (KOEO) Self-Test is a functional test of the powertrain control system performed on demand with the key on and engine off. A fault must be present at the time of testing for the KOEO Self-Test to detect the fault. When a fault is detected, a DTC will be output on the data link when requested by a scan tool.

Key ON Engine Running Self-Test
Key ON Engine Running (KOER) Self-Test is a functional test of the powertrain control system performed on demand with the engine running and vehicle stopped. A check of the inputs and outputs is made during operating conditions and at normal temperature. A fault must be present at the time of testing for the KOER Self-Test to detect the fault. When a fault is detected, a DTC will be output on the data link when requested by a scan tool.

Brake ON/OFF Test
On vehicles equipped with Brake ON/OFF (BOO) input, the brake pedal must be applied and released after KOER Self-Test is initiated. This tests the ability of the EEC system to detect a change of state in the stoplight switch.

Transmission Control Switch Test
On vehicles equipped with a Transmission Control Switch (TCS), the switch must be cycled after KOER Self-Test is initiated. This tests the ability of the EEC system to detect a change of state in the transmission control switch.

Power Steering Pressure Test
On vehicles equipped with a Power Steering Pressure (PSP) switch or sensor, the steering wheel must be turned at least 1/4 of a revolution after KOER Self-Test is initiated. This tests the ability of the EEC System to detect a change in the power steering system fluid pressure.

4x4 Low Switch Test
On vehicles equipped with a 4x4 Low Switch (4x4L), the switch must be cycled after KOER Self-Test is initiated. This tests the ability of the EEC system to detect a change in 4x4 Low status.

Continuous Memory DTC Access
Continuous Memory DTC Access is also a self-test of the powertrain control system. Unlike the KOEO and KOER self-tests, which can only be activated on demand, the Continuous Self-Test is always active. The test consists of all the OBD II monitors and the Comprehensive Component Monitor, and it is designed to detect failures contributing to driveability or emission concerns. When this test detects a fault, a DTC will be stored in PCM memory. The DTC can be retrieved at a later time even if the fault no longer exists. This capability makes Continuous Self-Test valuable when diagnosing intermittent faults.

As part of Quick Test, the technician retrieves DTCs that have been stored in Continuous Memory. During pinpoint testing, the technician may perform a specific drive cycle before running Quick Test. This is necessary to detect certain faults not tested during KOEO or KOER Self-Tests. When using an New Generation STAR (NGS) Tester, it is possible to select "Retrieve Continuous Codes" in both the NGS Diagnostic Data Link and generic menu. Under the generic OBD II functions menu, only the Malfunction Indicator Lamp (MIL) DTCs are output. Under the NGS Diagnostic Data Link menu, all Continuous Memory DTCs (MIL and non-MIL) are output. MIL DTCs activate the CHECK ENGINE or SERVICE ENGINE SOON indicator in the instrument cluster and are only generated for faults with the emission controls. Generally, non-MIL DTCs are for controls other than the emission system (i.e., A/C Cycling Switch or TR Sensor faults).

Any scan tool that meets OBD II requirements can access Continuous Memory to retrieve MIL DTCs. However, when performing KOEO or KOER Self-Test or retrieving all Continuous Memory DTCs (MIL and non-MIL) with a generic scan tool, it may require additional manually entered commands. All self-tests are menu-driven in the NGS Tester.

When using a generic scan tool, it is also possible to access MIL DTCs that are pending and have not actually turned on the MIL. A pending DTC applies to a fault set during the first drive after a PCM reset that has not turned on the Malfunction Indicator Lamp. Pending DTC retrieval is useful for a repair verification without the need to drive the vehicle through more than one drive cycle. Previously, an MIL DTC was not accessible by a generic scan tool until the MIL illuminates.

During most diagnostic procedures in this manual, it is required that all DTCs be retrieved. It is necessary to use either the NGS Diagnostic Data Link Menu or the Expanded Diagnostic Protocol (EDP) mode in the generic scan tool.

Expanded Diagnostic Protocol (EDP)
The Expanded Diagnostic Protocol mode on the generic Scan Tool accesses enhanced diagnostic information to repair emission-related faults. This information may be required by the manufacturer to diagnose components and sensors that affect vehicle emissions. For NGS, it is not necessary to use the EDP mode to access Quick Test.