System Tests: Intermittent
- Perform PCM Reset to clear FMEM
Connect scan tool to DLC. Turn ignition on, engine off. Ensure freeze frame data has been recorded before resetting PCM. Complete PCM reset. See QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If PCM reset is complete, go to next step. If PCM reset is not complete, perform PCM reset. Go to next step. - Select PIDs Related To Symptom
A list of PIDs is needed for use with scan tool to indicate area of fault. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Highlight each PID related to symptom. After all PIDs related to symptom have been chosen, go to next step. - Decision To Verify Symptom
Path of symptom verification is optional, but is recommended for several reasons. Some are because:- Vehicle is in for repeat repair.
- No DTC is present.
- Customer has difficulty describing symptom.
If symptom needs to be verified, go to next step. If symptom does not need to be verified, go to step 10.
NOTE: Only MIL codes will trigger freeze frame data. - Collect Any Available Data To Aid In Symptom Verification
Prepare freeze frame data for use which was recorded earlier from the Diagnostic Index. Continuous Memory DTCs should already be recorded from an earlier test. Access any other available data from customer. If all data has been recorded, go to next step. If all data has not been recorded, gather as much information as possible to aid in isolation of intermittent fault area. Go to next step.NOTE: Vehicle may require some driving to proceed with this test step. - Re-Create Symptom Using All Data
Concern must be verified by re-creating conditions that originally set DTC. With scan tool, select and monitor same PIDs as displayed in freeze frame along with previous highlighted PIDs from step 2. Using freeze frame data recorded earlier, re-create conditions described by each freeze frame PID. Pay special attention to ECT/CHT, LOAD, RPM and VSS PIDs. Also, use any available customer data to aid in producing correct conditions for re-creating symptom. When symptom occurs, press trigger to begin recording. If symptom could be reproduced, go to step 10. If symptom could not be reproduced, go to next step.NOTE: PIDs for outputs represent commanded values only. Circuit measurements with DVOM indicate actual output status. Therefore, in case of a fault, PID and circuit reading on vehicle may not correspond with each other. PIDs for PCM inputs with a mismatch to circuit measurement indicate a possible PCM concern. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. - Re-create Symptom Using KOEO Road Test Procedure
Road test is the last attempt to locate area of concern before physically disturbing vehicle circuits. Intermittent Road Test Procedure is a set of instructions for monitoring PIDs with scan tool or DVOM. This is done under four different conditions:- KOEO
- HOT IDLE
- 30 MPH
- 55 MPH
Use PID/DATA MONITOR to compare with actual vehicle values. For 30 and 55 MPH procedures, a planned route with passenger is required. Locate corresponding PIN/PID Chart. Refer to appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Set vehicle up to measure circuits with a scan tool or DVOM. Connect scan tool to DLC. Turn ignition on, engine off. Select and monitor PIDs and also measure circuits shown in PIN/PID Chart. Compare scan tool PIDs and DVOM values to values listed in PIN/PID Chart. If any values are out-of-range, go to step 10. If values are not out of range, go to next step.
- Re-Create Symptom Using Hot Idle Road Test Procedure
Turn ignition on, engine running and at least 195°F (87°C). Continue to monitor same PIDs and circuits as in previous step at hot idle. If any values are out-of-range, go to step 10. If values are not out of range, go to next step. - Re-Create Symptom Using 30 MPH Slow Cruise Road Test Procedure
Drive vehicle on preplanned route. Continue to monitor same PIDs and circuits during slow cruise as in previous step. If any values are out-of-range, go to step 10. If values are not out of range, go to next step. - Re-Create Symptom Using 55 MPH High Cruise Road Test Procedure
Continue to drive vehicle on preplanned route. Continue to monitor same PIDs and circuits during high cruise as in previous step. If any values are out-of-range, go to next step. If values are not out of range, it is now necessary to physically disturb selected vehicle circuits in an attempt to re-create intermittent concern. Go to next step. - Select Circuits From The PID/DATA Monitor Table
Remain in PID selection menu with scan tool. If Intermittent Road Test was used to verify symptom, highlight related PIDs or signals that displayed a mismatch to values listed in appropriate PIN/PID Charts. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Otherwise, highlight only the PIDs from step 2. Match selected PIDs to the corresponding circuit. There may be more than one circuit to test. If a PID recording was made with scan tool, it may be helpful to replay at this time (refer to scan tool instruction manual for recorder function). Select and proceed to appropriate test:- Input Test
Used on sensing devices such as temperature, position or oxygen. - Output Test
Used on output devices such as relays, coils or solenoids.
If a test has been chosen:
- For input test, go to next step.
- For output test, go to step 15.
If no mismatch has been detected, go to DTC P1001: DATA LINK CONNECTOR - MALFUNCTION .
WARNING: When performing any of the test steps, always be aware of hands, clothing or tools near cooling fans or hot surfaces. - Input Test
- KOEO Input Test Procedure For PCM Sensors
Select only related PID(s) to monitor with scan tool. If a PID is not available for circuit, use a DVOM. Proceed to area of suspect wiring or component fault. Turn ignition on, engine off. If input is a switch-type component, turn on manually. Monitor PID or DVOM values while tapping on component. Monitor while wiggling sensor harness wire from component to PCM. Look for abrupt changes in values. Compare actual values to KOEO PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If values are fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step. - KOER Input Test Procedure For PCM Sensors
Repeat step 11 with ignition on, engine running. If any values are fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step. - KOEO Water Soak Test Procedure For PCM Sensors
Turn ignition on, engine off. Continue to monitor PIDs or circuits with scan tool as in step 12. Proceed to the area of suspect wiring or component fault. If input is a switch-type component, turn on manually. Monitor PID or DVOM values while lightly spraying a water mist on suspect component. Monitor while spraying sensor harness wire from suspect component to PCM. Look for abrupt changes in values. Compare actual values to KOEO PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Are any values fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step. - KOER Water Soak Test Procedure For PCM Sensors
With ignition on, engine running, repeat step 13. If values are fluctuating in and out-of-range, repair as necessary. If no problem is found, go to step 19.NOTE: Output Test Mode may not control some outputs, such as injectors and ignition coils. To test these output types, go to step 16. Caution must be used for next steps. Cooling fans or fuel pump may turn on. - KOEO Output Test Procedure For PCM Actuators
Select related PID(s) to monitor using scan tool. Also, use a DVOM to compare circuit values with scan tool PID values. If PIDs are not available for a particular circuit, look for a DVOM fluctuation to occur when doing any of the following tests. Turn ignition on, engine off. With scan tool, turn all outputs on using OUTPUT TEST MODE. Proceed to area of suspect wiring or component fault. Monitor PID and DVOM values while tapping on component. Monitor while wiggling actuator harness wire from suspect component to PCM. Look for abrupt changes or PID to DVOM value mismatches. Also, compare the actual values to KOEO PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If there is a mismatch or there are any values fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step. - KOER Output Test Procedure For PCM Actuators
Turn ignition on, engine running. Proceed to area of suspect wiring or component fault. Monitor PIDs with scan tool (if PIDs are available) using PID monitor function. Compare the DVOM values with scan tool or look for a fluctuation in idle while tapping on suspect component. If a coil has been tapped and is suspect, with ignition off, it may be helpful to remove suspect coil and measure continuity from spark plug terminal to signal terminal while tapping the coil. A large fluctuation in resistance will indicate an intermittent open. Otherwise, monitor while wiggling actuator harness wire from component to PCM. Look for abrupt changes in idle or PID to DVOM value mismatches or fluctuation. Also, compare actual values to HOT IDLE PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If there is an idle fluctuation or DVOM value mismatch or fluctuation, repair as necessary. If no problem is found, go to next step.NOTE: Output Test Mode may not control some outputs, such as injectors. To test these output types, go to step 18. - KOEO Water Soak Test Procedure For PCM Actuators
Turn ignition on, engine off. With scan tool, turn all outputs on using Output Test Mode. Proceed to area of suspect wiring or component fault. Monitor PID and DVOM value while spraying a light mist of water on the component. Monitor while spraying actuator harness wire from component to PCM. Look for abrupt changes or PID to DVOM value mismatches. Also, compare actual values to KOEO PID/DATA. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If there is a PID to DVOM value mismatch or fluctuation in and out-of-range according to PIN/PID CHARTS, repair as necessary. If no problem is found, go to next step. - KOER Water Soak Test Procedure For PCM Actuators
Repeat step 17 with ignition on, engine running. If there is an idle fluctuation, value mismatch or values fluctuating in and out-of-range according to PIN/PID CHARTS, repair as necessary. If no problem is found, go to next step.NOTE: It is possible for an intermittent mechanical concern to cause a good PCM system to react abnormally. - Inspect For Intermittent Mechanical Concerns
An inspection of mechanical systems relating to the DTC or symptom should have been performed in an earlier section. If not, visually inspect at this time. Look for possibility of wires, vacuum lines or hoses that may short or kink during normal engine operation, such as:- Engine rock during acceleration.
- Components moving during conditions of vibrations (high RPM or rough road).
- Accelerator or transaxle linkage contact or interference.
If a mechanical concern is detected, repair as necessary. If mechanical concern is not found, unable to verify fault.