Z - Test
Z: Intermittent
Z: Introduction Z - Introduction
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Z1 DIRECTION FOR INTERMITTENT DIAGNOSTIC PATH
Note: Proceed with this step only if the powertrain control module (PCM) or transaxle control module (TCM) diagnostic trouble codes (DTCs) were not previously cleared. Record freeze frame data prior to clearing the PCM DTCs. Clearing the DTCs will clear any freeze frame data and eliminate FMEM. This helps to recreate the original conditions that set the DTCs or caused the symptom.
- Key ON, engine OFF.
- Clear PCM DTCs first and then TCM DTCs.
Have the DTCs been cleared?
YES
GO to Z2.
NO
CLEAR the DTCs.
GO to Z2.
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Z2 SELECT THE PIDS AND/OR SIGNALS RELATED TO THE SYSTEM
- A list of related PIDs and/or signals are needed for use with the scan tool to monitor the suspect areas. Obtain the customer symptom description. Use the Reference Value Symptom chart and proceed to the Reference Value PID/Signal Measurement chart located at the beginning of Typical Diagnostic Reference Values Typical Diagnostic Reference Value Notes.
- Highlight each available PID/signal recommended by the charts under the PID/signal selection menu on the scan tool.
Have all available PIDs/signals related to the symptom been selected?
YES
GO to Z3.
NO
REPEAT the test step to obtain the required information.
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Z3 DECISION TO VERIFY THE SYMPTOM
Note: The path to symptom verification is optional, but is recommended for several reasons. For example:
- The vehicle is in for a repeat repair.
- No DTC is present.
- Customer has difficulty describing the symptom.
Has a symptom been detected?
YES
GO to Z10.
NO
GO to Z4.
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Z4 COLLECT ANY SYMPTOM RELATED DATA TO AID IN VERIFICATION
Note: Only malfunction indicator lamp (MIL) codes trigger freeze frame data. Refer to the scan tool instruction manual to retrieve the freeze frame information.
- Prepare the freeze frame data for use with information from the Symptom Charts.
- Check the continuous memory DTCs that should have been recorded from an earlier pinpoint test.
- Access information from the customer information worksheet and the customer if available. Access any other symptom related data available, such as TSBs and CQIS reports.
Has all available data been recorded?
YES
GO to Z5.
NO
GATHER as much data as possible to aid in isolating the intermittent concern area.
REPEAT the test step to obtain the required information.
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Z5 RECREATE THE SYMPTOM USING ALL AVAILABLE DATA
Note: The vehicle may need to be driven in order to recreate the original conditions that set the DTC or caused the symptom.
- With the scan tool, select and monitor the same PIDs as displayed in freeze frame along with previously selected PIDs/signals from Step Z2. Using freeze frame data recorded earlier, recreate the conditions described by each freeze frame PID. Pay special attention to ECT, LOAD, RPM and VSS. Also, use any available data from the customer, TSBs, and other sources to aid in producing the correct conditions for recreating the symptom.
- When the symptom occurs, press the trigger to begin recording. Refer to the scan tool instruction manual for information on the recorder function.
Could the symptom be recreated?
YES
GO to Z10.
NO
GO to Z6.
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Z6 RECREATE THE SYMPTOM
Note: PIDs for output in the Reference Value Charts represent command values only. Circuit measurements with a DMM indicate the actual output status. Therefore, in the case of a concern, the PID and circuit reading on the vehicle may not correspond with each other. PIDs for PCM/TCM circuits with a mismatch in the DMM measurement.
- The road test is the last attempt to locate the area of concern before physically disturbing vehicle circuits.
- The Intermittent Road Test Procedure is a set of instructions for monitoring PIDs/signals with a scan tool and circuit measurements with a DMM. This is done under 4 different conditions - key on/engine off, hot idle, 48 km/h (30 mph) and 88 km/h (55 mph). Use the typical diagnostic reference values from Typical Diagnostic Reference Values to compare with the actual vehicle.
- Locate the correct Reference Value Chart.
- Setup the vehicle to measure the circuits with a DMM and a scan tool.
- Connect the scan tool to the data link connector (DLC).
- Key ON, engine OFF.
- With the scan tool, select and monitor PIDs and measure circuits shown in the Reference Value Chart.
- Compare the scan tool PIDs and digital multimeter values to the Reference Value Charts.
Are any values out of range?
YES
GO to Z10.
NO
GO to Z7.
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Z7 RECREATE THE SYMPTOM USING THE HOT IDLE ROAD TEST
- The engine temperature should be at least 87°C (189°F).
- Key ON, engine running.
- Continue to monitor the PIDs and circuits as in the previous step.
Are any values out of range?
YES
GO to Z10.
NO
GO to Z8.
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Z8 RECREATE THE SYMPTOM DURING AN 48 KM/H (30 MPH) ROAD TEST
- Drive the vehicle on a preplanned route.
- Continue to monitor the PIDs and circuits as in the previous step.
Are any values out of range?
YES
GO to Z10.
NO
GO to Z9.
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Z9 RECREATE THE SYMPTOM DURING AN 88 KM/H (55 MPH) ROAD TEST
- Continue to drive the vehicle on the preplanned route.
- Continue to monitor the PIDs and circuits as in the previous step.
Are any values out of range?
YES
GO to Z10.
NO
Attempt to recreate the intermittent concern.
GO to Z10.
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Z10 SELECT CIRCUITS FROM THE INTERMITTENT TEST CHART
- Remain in the PID/Signal selection menu with the scan tool.
- If the intermittent road test step was used to verify the symptom, highlight the PIDs/signals that were displayed as a mismatch to the Reference Values from Typical Diagnostic Reference Values. Otherwise, highlight only the PIDs/signals from step Z2.
- Proceed to the Intermittent Test chart located at the beginning of this pinpoint test.
- Match the selected PIDs/signals to the corresponding circuit in the chart. There may be more than one circuit to test. If a PID/signal recording was made with the scan tool, it may be helpful to replay it at this time. Refer to the scan tool instruction manual for additional information.
- Input Test - used on sensing inputs such as temperature, position or oxygen.
- Output Test - used on output devices such as relays, coils or solenoids.
Has a test been chosen?
YES
For the input test step, GO to Z11
.
For the output test step, GO to Z16.
NO
REFER to Symptom Charts Symptom Related Diagnostic Procedures
, Symptom Charts to diagnose other driveability symptoms.
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Z11 KOEO INPUT TEST PROCEDURE FOR THE PCM/TCM SENSORS
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
- Using the circuits chosen from the Intermittent Test Chart, select only the recommended PIDs/signals to monitor with the scan tool. If a PID is not available for the circuit, use a DMM to check the value.
- Proceed to the area of the suspect wiring or component concern.
- Key ON, engine OFF.
- If the input is a switch type-component, turn it on manually.
- Monitor the PID or DMM while tapping on the component.
- Monitor while wiggling the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values Pinout Values and Diagnostic Parameters .
Are there abrupt changes in the PID values that do not compare with Typical Diagnostic Reference Values readings?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z12.
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Z12 KOER INPUT TEST PROCEDURE FOR THE PCM/TCM SENSORS
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
- Key ON, engine running.
- Continue to monitor the PIDs and circuits as in the previous step.
- Proceed to the area of the suspect wiring or component concern.
- If the input is a switch type-component, turn it on manually.
- Monitor the PID or DMM while tapping on the component.
- Monitor while wiggling the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values Pinout Values and Diagnostic Parameters .
Are any values fluctuating in and out of range?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z13.
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Z13 KOEO WATER SOAK TEST PROCEDURE FOR THE PCM/TCM SENSORS, EXCLUDING HIGH VOLTAGE CIRCUITS
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
- Key ON, engine OFF.
- Continue to monitor the PIDs and circuits as in the previous step.
- Proceed to the area of the suspect wiring or component concern.
- If the input is a switch type-component, turn it on manually.
- Monitor the PID or DDM values while lightly spraying a water mist on the component to PCM/TCM.
- Monitor while spraying the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values Pinout Values and Diagnostic Parameters .
Are any values fluctuating in and out of range?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z14.
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Z14 KOER WATER SOAK TEST PROCEDURE FOR THE PCM/TCM SENSORS, EXCLUDING HIGH VOLTAGE CIRCUITS
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
- Key ON, engine running.
- Continue to monitor the PIDs and circuits as in the previous step.
- Proceed to the area of the suspect wiring or component concern.
- If the input is a switch type-component, turn it on manually.
- Monitor the PID or DMM values while lightly spraying a water mist on the component to PCM/TCM.
- Monitor while spraying the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values Pinout Values and Diagnostic Parameters .
Are any values fluctuating in and out of range?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z15.
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Z15 KOER WIGGLE TEST PROCEDURE FOR THE PCM/TCM SENSORS, EXCLUDING HIGH VOLTAGE CIRCUITS
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
NOTICE:The cooling fans or the fuel pump may turn on during the next steps.
- Using the circuits chosen from the Intermittent Test Chart, select only the recommended PIDs/signals to monitor with the scan tool. If a PID is not available for the circuit, use a digital multimeter to check the value.
- Key ON, engine OFF.
- With the scan tool, turn on selected outputs using output state control. Refer to the scan tool instruction manual.
- Proceed to the area of the suspect wiring or component concern.
- Monitor the PID or DMM while tapping on the component.
- Monitor while wiggling the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values. Pinout Values and Diagnostic Parameters .
Is there a mismatch between command and actual, or are any values fluctuating in and out of range when compared to the Reference Value Charts?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z16.
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Z16 KOEO WATER SOAK TEST PROCEDURE FOR THE PCM/TCM ACTUATORS, EXCLUDING HIGH VOLTAGE CIRCUITS
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
Note: Remember that PIDs selected from the Intermittent Test Chart display commanded values only. A DMM measurement is needed to display the actual values. Make sure to compare them. Look for fluctuations to occur during any part of the following test. The Output State Test may not control some outputs, such as injectors and ignition coils and may not be available for all actuators.
- Key ON, engine running.
- Proceed to the area of the suspect wiring or component concern.
- Monitor the PIDs with the scan tool and note the values. Compare the scan tool values with values from a DMM with the engine at idle. Look for fluctuations in the values while tapping on the suspect component.
- If a coil for a coil on plug application is suspect, turn off the key. Gain access to the coil and measure continuity from the spark plug terminal to the signal terminal while tapping the coil. A large fluctuation in resistance indicates an intermittent open or short.
- Monitor the PIDs while wiggling the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values Pinout Values and Diagnostic Parameters .
Is there a scan tool to DMM value mismatch or an idle fluctuation?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z17.
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Z17 KOEO WATER SOAK TEST PROCEDURE FOR THE PCM/TCM ACTUATORS, EXCLUDING HIGH VOLTAGE CIRCUITS
WARNING: WHEN CARRYING OUT THE WATER SOAK TEST ON ELECTRICAL COMPONENTS AND/OR HARNESSES, AVOID CONTACT WITH THE PCM, TCM, GENERIC ELECTRONIC MODULE (GEM), AND OTHER MODULES IF POSSIBLE. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
Note: Remember that PIDs selected from the Intermittent Test Chart display commanded values only. A DMM measurement is needed to display the actual values. Make sure to compare them. Look for fluctuations to occur during any part of the following test. The Output State Test may not control some outputs, such as injectors and ignition coils and may not be available for all actuators.
- Key ON, engine OFF.
- With the scan tool, turn on selected outputs using output state control. Refer to the scan tool instruction manual.
- Proceed to the area of the suspect wiring or component concern.
- Monitor the PID or DMM values while lightly spraying a water mist on the component to PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values in Pinout Values and Diagnostic Parameters .
Is there a mismatch between command and actual or are any values fluctuating in and out of range when compared to the Reference Value Charts?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z18.
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Z18 KOER WATER SOAK TEST PROCEDURE FOR THE PCM/TCM ACTUATORS
WARNING: WHEN CARRYING OUT THE WATER SOAK TEST ON ELECTRICAL COMPONENTS AND/OR HARNESSES, AVOID CONTACT WITH THE PCM, TCM, GEM, AND OTHER MODULES IF POSSIBLE. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
WARNING: WHEN CARRYING OUT ANY TEST STEPS, ALWAYS BE AWARE OF HANDS, CLOTHING, OR TOOLS NEAR COOLING FANS, BELTS, OR HOT SURFACES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
- Key ON, engine running.
- Using the circuits chosen from the Intermittent Test Chart, select only the recommended PIDs/signals to monitor with the scan tool. If a PID is not available for the circuit, use a digital multimeter to check the value.
- Proceed to the area of the suspect wiring or component concern.
- Monitor the PID or DMM values while lightly spraying a water mist on the component to PCM/TCM.
- Monitor while spraying the sensor harness wire from the component to the PCM/TCM.
- Look for abrupt changes in the values. Compare these actual values to the Typical Diagnostic Reference Values in Pinout Values and Diagnostic Parameters .
Is there a mismatch between command and actual or are any values fluctuating in and out of range when compared to the Reference Value Charts?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
GO to Z19.
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Z19 INSPECT FOR INTERMITTENT MECHANICAL CONCERNS
Note: It is possible for an intermittent mechanical concern to cause a good PCM/TCM system to react abnormally.
- An inspection of DTC related mechanical systems should have been performed earlier. If not, visually inspect at this time.
- Look for possible vacuum lines, wires, cables, linkage, or hoses that may become kinked, shorted, or restricted during normal engine operation.
- This may include engine/transmission gear changes, acceleration and deceleration, rough roads, and various engine RPM and torque related conditions.
Is a mechanical concern detected?
YES
REPAIR as necessary.
TEST the system for normal operation.
NO
It is necessary to seek additional help. REFER to the Professional Technician Society (PTS) web site, the OASIS system or the Technical Hotline. A vehicle data recorder (VDR) or similar recorder may also be useful.