Diagnostic Aids
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat QUICK TEST procedures to ensure all EEC-V systems are working properly and DTCs are no longer present.
Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:
- Wiring harness circuits (B+, EAIR, EAIR monitor and ground).
- Solid State Relay (SSR).
- Electric Air Pump (EAP). See Fig 1.
- Air injection by-pass solenoid.
- Air injection diverter solenoid.
- Air injection diverter valve.
- Powertrain Control Module (PCM).
NOTE:
Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION table of fault code setting condition.
FAULT CODE SETTING CONDITION
| Fault Code | KOEO | KOER | Continuous Memory |
|---|---|---|---|
| P0411 | HM7 | HM7 | HM7 |
| P0412 | HM1 | HM1 | HM1 |
| P1413 | HM19 | HM19 | HM19 |
| P1414 | HM27 | HM27 | HM27 |
- 1) DTC P0412: Check B+ Voltage To Solid State Relay
This DTC indicates EAIR primary circuit failure. Possible causes are:- EAIRM Circuit Open Or Short To Power
- AIR By-Pass Solenoid Failure
- Faulty Solid State Relay (SSR)
- Faulty PCM
Turn ignition switch to OFF position. Disconnect SSR harness connector. Turn ignition switch to ON position. Using a DVOM, measure voltage of B+ circuit between SSR harness connector and negative battery terminal. See Fig 2. If voltage is more than 10.5 volts, supplied voltage is okay. Go to next step. If voltage is 10.5 volts or less, go to step 6).
- 2) Check EAIR Circuit Resistance
Turn ignition switch to OFF position. Disconnect AIR by-pass solenoid. Temporarily remove secondary air injection system dedicated fuse. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of EAIR circuit between PCM harness connector, SSR harness connector and secondary air injection by-pass solenoid harness connector. See Fig 2. If either resistance measurement is 5 ohms or more, repair open in affected circuit. If both resistance measurements are less than 5 ohms, go to next step. - 3) Check EAIR Circuit Short To Power
On LS, measure resistance between PCM connector terminals No. A19 and VPWR fuse. On all other models, measure resistance between PCM connector terminals No. 70 and 71 (VPWR). Measure resistance between PCM connector terminal A19 (EAIR) on LS or terminal No. 70 (EAIR) on all other models and negative battery terminal. If both resistance readings are more than 10 k/ohms, go to next step. If any resistance reading is 10 k/ohms or less, repair short circuit. - 4) Check Air By-Pass Solenoid Resistance
Ensure AIR by-pass solenoid is disconnected. Using a DVOM, measure resistance between both AIR by-pass solenoid connector terminals. If resistance measurement is 50-100 ohms, go to next step. If resistance measurement is not 50-100 ohms, replace AIR by-pass solenoid. - 5) Check EAIR Circuit For Short To PWR Or GND With SSR Connected
Ensure AIR by-pass solenoid is disconnected. Reconnect SSR harness connector. Using a DVOM, measure resistance between PCM harness connector EAIR, PWR GND and VPWR circuit terminals. See WIRING DIAGRAMS article. See Figure, Figure and Fig 2 . If any resistance measurement is 10 k/ohms or less, replace SSR. If all resistance measurements are more than 10 k/ohms, reconnect all connectors and go to step 9) for DTC P0411, or go to step 16) for all others. - 6) Check B+ Circuit For Open In Harness
Ensure SSR is disconnected. Using a DVOM, measure resistance of B+ circuit between SSR harness connector and secondary AIR system dedicated fuse output terminal. See Fig 2. If resistance is less than 5 ohms, check VPWR circuit for short to GND. Replace dedicated fuse, reconnect SSR and go to step 8). If resistance is 5 ohms or more, repair open in B+ circuit. Reconnect SSR and replace dedicated fuse. - 7) DTC P0411: Visually Inspect EAIR Pump Hoses & Air Silencer
Check EAIR pump air hoses from pump to AIR diverter valves for cracks, obstructions, water or ice (in colder climates). Check for damaged exhaust system. Check AIR silencer for obstructions. Repair as necessary. If components and hoses are okay, go to next step. - 8) Check Electric Pump Operation
Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, enter OUTPUT TEST MODE. If EAIR pump operates, turn ignition switch to OFF position and go to step 17). If EAIR pump does not operate, fault may be intermittent. Go to TEST Z . If no intermittent faults are found, go to step 13). - 9) Check For Vacuum At AIR Diverter Valves
Ensure ignition switch is turned to OFF position. Connect scan tool to Data Link Connector (DLC). Connect a vacuum gauge to AIR diverter valve(s) control vacuum hose. Using a hand vacuum pump, apply 16 in. Hg of vacuum to vacuum supply hose (intake manifold side) of AIR by-pass solenoid. Turn ignition switch to ON position. Using scan tool, enter OUTPUT TEST MODE. Vacuum should be present on vacuum gauge. If vacuum is present, go to next step. If vacuum is not present, go to step 32). - 10) Check AIR Diverter Valve Integrity
Turn ignition switch to OFF position. Disconnect air tube from diverter valve(s) outlet side. Check diverter valve outlet(s) for heat damage and repair if necessary. Using hand vacuum pump, apply 16 in. Hg of vacuum to AIR diverter valve(s). Turn ignition switch to ON position. Using scan tool, enter OUTPUT TEST MODE. If air is present from AIR diverter valve(s), turn ignition switch to OFF position and check exhaust tube(s) from AIR diverter valve to exhaust manifold(s). If exhaust tube(s) from diverter valve are okay, go to next step. If air is not present from AIR diverter valve(s), turn ignition switch to OFF position and check hose from EAIR pump to AIR diverter valve(s). Replace as necessary. If hose is okay, replace appropriate AIR diverter valve(s). - 11) Check Manifold Vacuum With Exhaust Manifold Disconnected
Disconnect exhaust pipe from exhaust manifold. Start engine and gradually raise engine speed to 2000 RPM. Observe vacuum gauge reading response while maintaining increased engine RPM. If manifold vacuum is okay, exhaust restriction is downstream of exhaust manifold. Reconnect exhaust system to exhaust manifold and go to next step. If manifold vacuum is low or slow to respond, restriction is present in exhaust manifold. Check exhaust manifold for restrictions. If restrictions are present and are unable to be removed, replace exhaust manifold. - 12) Check Manifold Vacuum With Muffler & Tailpipe Disconnected
Disconnect muffler and tailpipe assembly. Start engine and raise engine speed to 2000 RPM. Monitor rate of vacuum gauge needle climb while maintaining 2000 RPM. If vacuum gauge needle climbs quickly to more than 16 in. Hg (53 kPa), restriction is in muffler and tailpipe assembly. Replace muffler and tailpipe assembly. If vacuum gauge needle does not climb quickly to more than 16 in. Hg (53 kPa), restriction is present in catalytic converter. Replace catalytic converter and ensure muffler was not plugged by converter debris. - 13) Check EAIRM Circuit Voltage
Connect scan tool to Data Link Connector (DLC). Turn ignition switch to OFF position. Disconnect EAIR pump. Turn ignition switch to ON position. Using scan tool, enter OUTPUT TEST MODE. Using a DVOM, measure voltage of EAIRM circuit between EAIR pump harness connector and negative battery terminal. See Fig 2. If voltage is more than 10.5 volts, go to step 15). If voltage is 10.5 volts or less, go to next step. - 14) Check Ground Circuit
Using a DVOM, measure resistance between EAIR pump harness connector GND terminal and negative battery terminal. See Fig 2. If resistance is less than 5 ohms, go to step 21). If resistance is 5 ohms or more, repair open in GND circuit. - 15) Check Input Air Pump Hose
Disconnect electric AIR pump air inlet hose. Check hose for water, restriction and binding. Replace hose as necessary and go to step 17). If hose is okay, go to step 17). - 16) Check Solid State Relay Output
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Reconnect AIR by-pass solenoid. Reconnect PCM harness connector. Ensure SSR is connected. Turn ignition switch to ON position. Using scan tool, select AIR and AIRM PIDs from PID/DATA MONITOR & RECORD menu. Compare AIR and AIRM PID readings. If both PID readings indicate ON, replace SSR. If either PID value indicates OFF, fault may be intermittent. Go to TEST Z . If no intermittent faults are found, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . - 17) Check Air Pump For Water
Turn ignition switch to OFF position. Disconnect electric pump air hoses and harness connector. Check AIR pump for water. If water is present, replace electric pump. If water is not present proceed as follows:- If fuse was replaced in step 6) , testing is complete.
- On all others, go to step 9).
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 17) to step 19). No test procedures have been omitted. - 19) DTC P1413: Check For Battery Voltage At SSR
This DTC indicates EAIRM circuit is low when electric AIR pump is commanded on. Possible causes are:- EAIRM Circuit Open Or Short To Power
- Faulty Solid State Relay (SSR)
- Faulty Electric AIR Pump
- Faulty PCM
Turn ignition switch to OFF position. Disconnect SSR. Turn ignition switch to ON position. Measure voltage between B+ terminal at SSR harness connector and negative battery terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, go to step 26).
- 20) Check VPWR To SSR
Turn ignition switch to ON position. Measure voltage between VPWR circuit terminal at SSR harness connector and chassis ground. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less (LS V6 models), go to TEST B, step 5), or (all other models), repair open circuit. - 21) Check EAIRM Circuit Voltage
Turn ignition switch to OFF position. Ensure scan tool is connected to Data Link Connector (DLC). Reconnect SSR harness connector. Disconnect EAIR pump harness connector. Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Select START to turn outputs ON. Using scan tool, select AIRM PID from PID/DATA MONITOR & RECORD menu. If AIRM PID value indicates ON, remain in OUTPUT TEST MODE and go to step 25). If PID value indicates OFF and DTC P0411 is present, replace AIR pump. If PID value indicates OFF and DTC P0411 is not present, go to next step. - 22) Check EAIRM Circuit For Short To Power
Ensure ignition switch is turned to ON position. Using scan tool, select AIRM PID from PID/DATA MONITOR & RECORD menu. If AIRM PID value indicates ON, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If AIRM PID value indicates OFF, go to next step. - 23) Check EAIRM Circuit For Open In Harness
Turn ignition switch to OFF position. Disconnect SSR and EAIR pump harness connectors. Using a DVOM, measure resistance of EAIRM circuit between PCM harness connector and SSR harness connector. See Fig 2. Using a DVOM, measure resistance of EAIRM circuit between SSR harness connector and EAIR pump harness connector. If either resistance measurement is 5 ohms or more, repair open in EAIRM circuit. If both resistance measurements are less than 5 ohms, go to next step. - 24) Check EAIRM Circuit For Short To Ground
Using a DVOM, measure resistance between PCM harness connector EAIRM and PWR GND circuit terminals. See Fig 2. If resistance measurement is more than 10 k/ohms, replace SSR. If resistance measurement is 10 k/ohms or less, repair short to ground in EAIRM circuit. - 25) Check EAIRM Circuit Voltage To PCM
Reconnect EAIR pump. Reconnect PCM harness connector. Turn ignition switch to ON position. Ensure scan tool is still in OUTPUT TEST MODE and all outputs are selected ON. Using scan tool, select AIRM PID from PID/DATA MONITOR & RECORD menu. If AIRM PID value indicates ON, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If PID value indicates OFF, repair open in EAIRM circuit. - 26) Check B+ Circuit For Open In Harness
Using a DVOM, measure resistance of B+ circuit between SSR harness connector and SSR dedicated fuse. See Fig 2. If resistance is less than 5 ohms, replace SSR dedicated fuse. If resistance is 5 ohms or more, repair open in B+ circuit. - 27) DTC P1414: Check EAIR MONITOR Circuit Continuity
This DTC indicates electric AIR pump is commanded off, but PCM indicates AIR pump is on. Possible causes are:- EAIRM Circuit Open Or Short To Power
- Faulty Solid State Relay (SSR)
- Faulty Electric AIR Pump
- Faulty PCM
Turn ignition switch to OFF position. Disconnect EAIR pump and SSR harness connectors. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of EAIRM circuit between PCM harness connector and EAIR pump harness connector. See Fig 2. If resistance is 5 ohms or more, repair open in EAIRM circuit. If resistance is less than 5 ohms, go to next step.
- 28) Check AIR Pump Resistance
Measure resistance between electric AIR pump terminals. If resistance is .5-5.0 ohms, go to next step. If resistance is not .5-5.0 ohms, replace AIR pump. - 29) Check EAIR MONITOR Circuit For Short To Power
Turn ignition switch to ON position. Measure voltage between PCM connector terminal No. 5 and chassis ground. If voltage is 10.5 volts or less, go to next step. If voltage is more than 10.5 volts, repair short to power. - 30) Check Solid State Relay Output
Reconnect all connectors. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Select START to turn outputs ON. Access AIR and AIRM PIDs from PID/DATA MONITOR & RECORD menu. Observe PID values. If both PID readings indicate ON, replace SSR. If either PID value indicates OFF, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE .NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 30) to step 32). No test procedures have been omitted. - 32) Check Vacuum Hose Integrity
Turn ignition switch to OFF position. Remove vacuum hose between intake manifold and AIR diverter valve(s). Check hose for cracks, binding, obstructions, water or ice (in colder climates). Replace or repair hose as necessary. If hose is okay, go to next step. - 33) Check AIR By-Pass Solenoid Electrical Operation
Ensure scan tool is connected to DLC. Disconnect air by-pass solenoid connector. Turn ignition switch to ON position. Using scan tool, select OUTPUT TEST MODE. Connect DVOM between both AIR by-pass solenoid harness connector terminals. See Fig 2. Observe DVOM voltage reading while cycling outputs ON and OFF. If voltage reading cycles more than .5 volt, remain in OUTPUT TEST MODE and go to next step. If voltage reading does not cycle more than .5 volt, turn ignition switch to OFF position and go to step 35). - 34) Check AIR By-Pass Solenoid Mechanical Operation
Ensure scan tool is in OUTPUT TEST MODE. Reconnect AIR by-pass solenoid harness connector. Disconnect source vacuum hose from AIR by-pass solenoid. Connect hand vacuum pump to vacuum hose. Apply 16 in. Hg to AIR by-pass solenoid. Observe DVOM while cycling outputs ON and OFF. If vacuum does not release as outputs cycle ON and OFF, replace AIR by-pass solenoid. If vacuum releases as outputs cycle ON and OFF, repair vacuum hose between AIR by-pass solenoid and intake manifold vacuum tree. If hose is okay, go to TEST Z . - 35) Check Air By-Pass Solenoid Resistance
Turn ignition switch to OFF position. Disconnect AIR by-pass solenoid connector. Measure resistance between AIR by-pass solenoid terminals. If resistance is 50-100 ohms, go to next step. If resistance is not 50-100 ohms, replace AIR by-pass solenoid. - 36) Check VPWR Circuit Voltage
Turn ignition switch to ON position. Measure voltage between VPWR terminal at AIR by-pass solenoid harness connector and negative battery terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in VPWR circuit. - 37) Check EAIR Circuit For Open In Harness
Turn ignition switch to OFF position. Disconnect SSR harness connector. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of EAIR circuit between PCM harness connector and SSR harness connector. See Fig 2. Using a DVOM, measure resistance of EAIR circuit between PCM harness connector and AIR by-pass solenoid harness connector. If either resistance measurement is 5 ohms or more, repair open in EAIR circuit. If both resistance measurements are less than 5 ohms, go to next step. - 38) Check EAIR Circuit For Short To Ground In Harness
Turn ignition switch to OFF position. Using a DVOM, measure resistance between PCM harness connector EAIR and PWR GND circuit terminals. See Figure, Figure and Fig 2 . See WIRING DIAGRAMS article. If both resistance measurements are more than 10 k/ohms, go to next step. If either resistance measurement is 10 k/ohms or less, repair short to GND in EAIR circuit. - 39) Check EAIR Circuit For Short To Power
Using a DVOM, measure resistance between PCM harness connector EAIR and PWR GND circuit terminals. See Figure, Figure and Fig 2 . See WIRING DIAGRAMS article. If resistance is more than 10 k/ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If resistance is 10 k/ohms or less, repair short to PWR in EAIR circuit.
CAUTION:
Overheating and damage may occur to EAIR pump if operated in OUTPUT TEST MODE for longer than 2 minutes.
NOTE:
On 2-valve systems, ensure air flows from both valves.
NOTE:
An intake manifold gasket leak can cause vacuum gauge reading to remain below normal range.