DIAGNOSTIC TOOLS
Below is an equipment list with corresponding part numbers
REQUIRED SAFETY EQUIPMENT
Note. The rubber insulating gloves are to be worn while working on high-voltage components or high-voltage cables. They must be inspected before use and must be worn in conjunction with the leather outer glove. Any hole in the rubber glove is a potential entry point for high voltage. To inspect the glove roll it up from the open end until the lower portion of the glove begins to balloon from the resulting pressure. If the glove leaks any air it must not be used.
- Rubber insulating gloves
- NOTE: The safety face shield is to be worn while working on high-voltage components or high-voltage cables.
- Safety face shield
REQUIRED EQUIPMENT
- Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool with functionality described under Scan Tool Setup and Functionality.
- Rotunda Smoke Machine, Fuel Evaporative Emission System Tester 218-00001 (522) or equivalent.
RECOMMENDED EQUIPMENT
- Rotunda Vacuum/Pressure Tester 164-R0253 or equivalent. Range 0-101.3 kPa (0-30 in-Hg.) Resolution 3.4 kPa (1 in-Hg.)
- Rotunda Vacuum Tester 014-R1054 or equivalent. Range 0-101.3 kPa (0-30 in-Hg.)
- Digital Multimeter (DMM) FLU77-4 or equivalent.
- Adjustable Ignition Spark Tester THX458 or equivalent.
- Deluxe Noid Lite and Signal Test Light Set AST7898 or equivalent.
- Non-powered test lamp.
- Fuel Pressure T Adapter (5/16) 310-D251 or equivalent.
- Chassis Ears JSP06608-D or equivalent.
OPTIONAL EQUIPMENT
- Rotunda Fuel (Gasoline) Pressure Test Kit 134-R0087 or equivalent (Use tool manufacturer's instructions.)
SCAN TOOL SET-UP AND FUNCTIONALITY
Connect the scan tool to the data link connector (DLC) for communication with the vehicle.
The DLC is located in the driver side compartment. It is attached to the lower instrument panel under the steering column and is accessible from the driver seat.
The DLC is rectangular in design and capable of accommodating up to 16 terminals. The connector has keying features to allow easy connection. The vehicle connector and the test equipment connector have latching features that make sure the test equipment connector remains mated when correctly connected.
The required scan tool functions are listed below
- monitor, record, and playback of parameter identification (PIDs)
- freeze frame PID data
- diagnostic test modes; self-test, clear diagnostic trouble codes (DTCs)
- output state control
- resetting keep alive memory (KAM)
- diagnostic monitoring test results for on-board diagnostic (OBD) on-board monitors
- on board system readiness (OBD monitor completion status)
Some of these functions are described in this article. Refer to the scan tool manufacturer's manual for specific information on scan tool set-up and operation.
Quick Test
Note. Do not carry out consecutive quick tests without turning the ignition to the OFF position for a minimum of 15 seconds.
Note. Some faults within the hybrid electric system may prevent the TCM from executing the KOEO on demand self-test. When one or more of the following DTCs are stored in the TCM continuous memory the KOEO on demand self-test is not executed: P0613, P0A90, P0A1B, P0A1A, P2806 or P0A0A.
The quick test is divided into three specialized tests
- Key On Engine Off (KOEO) On Demand Self-Test
- Key On Engine Running (KOER) On Demand Self-Test
- Continuous Memory Self-Test
The quick test checks the integrity and function of the electronic engine control (EEC) system, and the hybrid electric system. The results of the quick test are requested and displayed on the scan tool. The quick test also provides a quick end check of both the powertrain control system and the hybrid electric system. It is usually carried out at the start of each diagnostic procedure with all accessories OFF. The quick test is also carried out at the end of most pinpoint tests for verification of the repair and to make sure no other faults were incurred while repairing a previous fault. A system pass is displayed when no diagnostic trouble codes (DTCs) are output and a scan tool communication error does not exist. System pass means that hardware monitored by the powertrain control module (PCM) is functioning within the normal operating limits. Only a system pass, a DTC, or an incomplete on board diagnostic (OBD) drive cycle is displayed.
Key On Engine Off (KOEO) On Demand Self-Test
The KOEO on demand self-test is a functional test of the PCM or the TCM and is carried out with the ignition ON and the engine OFF. This test carries out checks on certain input and output circuits. 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 is output on the data link at the end of the test when requested by a scan tool. The KOEO on demand self-test can be executed with the gear selector in PARK only.
Key On Engine Running (KOER) On Demand Self-Test
The KOER on demand self-test is a functional test of the PCM, and is carried out with the ignition in the START position, the engine running and the vehicle stopped. A check of certain inputs and outputs is made during operating conditions and at a normal temperature. The brake pedal position (BPP) test is a part of the KOER on demand self-test and must be carried out during this operation. A fault must be present at the time of testing for the KOER on demand self-test to detect the fault. When a fault is detected, a DTC is output on the data link at the end of the test when requested by a scan tool. The KOER on demand self-test can be executed with the gear selector in PARK only.
Brake Pedal Position (BPP) Test
This tests the ability of the EEC system to detect a change of state in the BPP switch. The brake pedal must be briefly applied and released on all vehicles equipped with a BPP input. This is done during a KOER on demand self-test.
Continuous Memory Self-Test
Note. In order to retrieve the DTCs, the scan tool communication protocol must be compatible with the vehicle communication protocol.
The continuous memory self-test is a functional test of the PCM and TCM carried out under any condition (engine running or OFF) with the ignition ON. Unlike the KOEO and KOER self-tests, which can only be activated on demand, the continuous self-test is always active. A concern does not need to be present when accessing continuous memory self-test DTCs, making the test valuable when diagnosing intermittent concerns. The vehicle may need to be driven or the on board diagnostic (OBD) drive cycle completed to allow the PCM to detect a concern. Refer to ON BOARD DIAGNOSTIC (OBD) DRIVE CYCLE for more information. When a concern is stored in memory, a DTC is output on the data link when requested by the scan tool.
There are three types of continuous DTCs
- an emission related malfunction indicator lamp (MIL) code which illuminates the CHECK ENGINE indicator in the instrument cluster.
- a non emission related, non MIL code which does not illuminate the CHECK ENGINE indicator, but illuminates the powertrain malfunction indicator (wrench), HAZARD, or both indicators.
- a non emission, non MIL code which does not illuminate any indicators.
For emission-related MIL DTCs, the PCM stores the DTC in continuous memory when a concern is detected for the first time. At this point the DTC does not illuminate the MIL and is considered a pending code. The purpose of pending codes is to assist in repair verification by reporting a pending DTC after one drive cycle. If the same concern is detected after the next drive cycle, the emission related MIL code illuminates the MIL and sets both a confirmed MIL DTC and a permanent DTC. The MIL remains illuminated even if the concern is intermittent. A permanent DTC is stored until three consecutive passing drive cycles have been completed after a repair and the MIL turns off, or after a request to clear DTCs has been made using the scan tool and the next monitoring cycle has completed and passed for that DTC.
Confirmed emission related MIL DTCs and any non emission related, non MIL DTCs are erased approximately 40 vehicle warm up cycles after the concern was last detected, or if the DTCs are cleared by the scan tool.
Pending emission-related MIL DTCs that never detect a concern on a second consecutive drive cycle (and never light the MIL) are not retained in memory for any number of vehicle warm up cycles; they are immediately cleared when the next monitoring cycle has completed and passed for that DTC, or until a request to clear DTCs has been made by the scan tool.
Any scan tool that meets OBD requirements can access the continuous memory to retrieve emission related MIL DTCs. However, not all scan tools access pending and non emission related, non MIL DTCs in the same way.
During most diagnostic procedures in this article, it is required that all DTCs be retrieved and cleared. Permanent DTCs cannot be directly cleared by the scan tool. When a scan tool clears DTCs, pending and confirmed DTCs are immediately cleared. Permanent DTCs will not clear until the next monitoring cycle has completed and passed for that DTC. For additional information, refer to POWERTRAIN CONTROL SOFTWARE , Permanent Diagnostic Trouble Code (DTC).
Engine Running Diagnostic Mode
The engine running diagnostic mode is a powertrain control module (PCM) strategy which is separate from the normal operating strategy. When in this mode, the engine is running and does not turn off, as it does during normal operation. The engine RPM may be increased to the desired speed as the vehicle is in the pedal follower mode. To activate the engine running diagnostic mode the gear selector must be in the PARK position, and the ignition cycled to the START position. The engine is allowed to idle as long as the powertrain and hybrid electric systems operate within the calibrated limits. The powertrain malfunction indicator (wrench) flashing once per second indicates the vehicle is in the engine running diagnostic mode. This mode is helpful whenever the engine must stay running for diagnostics and repairs that require the engine to be idling for extended time. Carry out the following sequence to activate this mode
- apply the parking brake
- place the gear selector in the PARK position
- ignition in the OFF position
- NOTE: Do not start the engine.
- ignition in the ON position with the engine OFF
- within 5 seconds of the ignition in the ON position, fully apply the accelerator pedal and hold for 10 seconds
- within 5 seconds release the accelerator pedal, shift the gear selector to the DRIVE position and fully apply the accelerator pedal
- hold the accelerator pedal fully applied for 10 seconds
- release the accelerator pedal and shift the gear selector to the PARK position
If the sequence is correctly executed the powertrain malfunction indicator (wrench) flashes once per second when the gear selector is shifted to the PARK position. The engine may be started by cycling the ignition to the START position. The PCM exits the engine running mode when the gear selector is shifted to any gear other than PARK, when the ignition is turned to the OFF or ACC position, or the powertrain or hybrid electric system exceeds calibrated limits.
Engine Cranking Diagnostic Mode
Note. Access the battery energy control module (BECM) and monitor the high voltage traction battery state of charge parameter identification (PID). If the monitored PID displays the state of charge below 45%, run the vehicle in the Engine Running Diagnostic Mode to raise the BECM state of charge. When the high voltage traction battery state of charge exceeds 45%, the engine cranking diagnostic mode can be activated.
The engine cranking diagnostic mode is a PCM strategy which is separate from the normal operating strategy. It allows the engine to crank in a similar fashion as a conventional vehicle with the fuel disabled. When in this mode, the PCM commands the TCM to spin the generator which cranks the engine with the speed between 900 and 1, 200 RPM. To activate the engine cranking diagnostic mode the gear selector must be in the PARK position, the high voltage traction battery state of charge must be greater than 45%, and the ignition must be cycled to the START position. The engine cranks as long as the high voltage traction battery state of charge stays greater than 35%. The hazard indicator (red triangle) flashing once per second indicates the vehicle is in the engine cranking diagnostic mode. In this mode the throttle plates can be moved from closed to open by applying and holding the break pedal before applying the accelerator pedal. After moving the throttle plate position twice, function may be disabled and diagnostic trouble code (DTC) P2111 may set. To carry out this function again, clear the DTCs and enter this mode again. This mode is helpful whenever the engine must be cranked but not started. Carry out the following sequence to activate this mode
- apply the parking brake
- place the gear selector in the PARK position
- ignition in the OFF position
- NOTE: Do not start the engine.
- ignition in the ON position with the engine OFF
- within 5 seconds of the ignition in the ON position, fully apply the accelerator pedal and hold for 10 seconds
- within 5 seconds release the accelerator pedal, shift the gear selector to the NEUTRAL position and fully apply the accelerator pedal
- hold the accelerator pedal fully applied for 10 seconds
- release the accelerator pedal and shift the gear selector to the PARK position
If the sequence is correctly executed the hazard indicator (red triangle) flashes once per second when the gear selector is shifted to the PARK position. The engine may be cranked by cycling the ignition to the START position. If the ignition stays in the START position for 15 seconds or longer, the PCM may set the DTC P2535. The PCM exits the engine cranking diagnostic mode when the high voltage traction battery state of charge drops below 35%, the gear selector is shifted to any gear other than PARK, or when the ignition is turned to the OFF or ACC position.
DIAGNOSTIC MONITORING TEST RESULTS MODE 6
Mode 6 allows access to the results of on board diagnostic (OBD) monitor diagnostic test results. The test values are stored at the time of the particular monitor completion. Refer to mode 6 on the scan tool for test information.
INTERMITTENT DIAGNOSTIC TECHNIQUES
Intermittent diagnostic techniques help find and isolate the root cause of intermittent faults associated with the electronic engine control (EEC) or the hybrid electric system. The information is organized to help find the fault and carry out the repair. The process of finding and isolating an intermittent fault starts with recreating a fault symptom, accumulating powertrain control module (PCM) data, and comparing that data to typical values, then analyzing the results. Refer to the scan tool users manual for the functions described below.
Before proceeding, be sure that
- Customary mechanical system tests and inspections do not reveal a concern. (Remember, mechanical component conditions can make a PCM system react abnormally.)
- Technical Service Bulletins (TSBs) and On-line Automotive Service Information System (OASIS) messages, if applicable, are reviewed.
- Quick test and associated diagnostic sub-routines have been completed without finding a fault, and the symptom is still present.
ADAPTIVE FUEL DIAGNOSTIC TROUBLE CODE (DTCS) DIAGNOSTIC TECHNIQUES
Adaptive fuel DTCs diagnostic techniques help isolate the root cause of the adaptive fuel concern. Before proceeding, attempt to verify if any driveability concerns are present. These diagnostic aids are meant as a supplement to the pinpoint test steps in Pinpoint Tests. For a description of fuel trim, refer to POWERTRAIN CONTROL SOFTWARE .