from the service manuals. Hope you can gather your answer from this.
DTC P1170 [ZM]
DTC P1170 HO2S (Front) no inversion
DETECTION CONDITION
* PCM monitors input voltage from HO2S (Front) when the following monitoring conditions are met. If input voltage from sensor remains below or above 0.45 V for 43.2 seconds , PCM determines that there is no HO2S (Front, RH) inversion.
o MONITORING CONDITIONS Engine speed is above 1,500 rpm .
o Engine coolant temperature is above 80 C {176 F} .
* Diagnostic support note This is a continuous monitor (CCM).
* MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles.
* PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
* FREEZE FRAME DATA is available.
* DTC is stored in PCM memory.
POSSIBLE CAUSE
* HO2S (Front) malfunction
* HO2S (Front) heater malfunction
* Fuel injector malfunction
* Pressure regulator malfunction
* Fuel pump malfunction
* Fuel delivery hose clogging or leakage
* Fuel filter clogging
* Fuel return hose clogging or leakage
* Air suction or leakage
* PCV valve malfunction
* Purge solenoid valve malfunction
* Purge solenoid hoses are hooked up incorrectly.
* Ignition coil malfunction
* Insufficient compression
* Engine malfunction
Diagnostic procedure
STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
* Has FREEZE FRAME DATA been recorded?
Yes Go to next step.
No Record FREEZE FRAME DATA on repair order, then go to next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY
* Check for related Service Bulletins and/or on-line repair information availability.
* Is any related repair information available?
Yes Perform repair or diagnosis according to available repair information.
* If vehicle is not repaired, go to next step.
No Go to next step.
3 VERIFY RELATED PENDING AND STORED DTCs
* Turn ignition key to OFF, then ON (Engine OFF).
* Verify pending and stored DTCs using NGS tester.
* Are other DTCs present?
Yes Go to appropriate DTC troubleshooting procedures.
No Go to next step.
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA
* Is DTC P1170 on FREEZE FRAME DATA?
Yes Go to next step.
No Go to troubleshooting procedures for DTC on FREEZE FRAME DATA.
5 VERIFY CURRENT INPUT SIGNAL STATUS IS CONCERN INTERMITTENT OR CONSTANT
* Warm up engine.
* Access FHO2S PID using NGS tester.
* Verify PID while racing engine (in PARK).
* Is PID reading okay?
o More than 0.45 V when suddenly depressing accelerator pedal (rich condition)
o Less than 0.45 V just after release of accelerator pedal (lean condition)
Yes Go to next step.
No Replace front HO2S, then go to Step 21.
6 INSPECT LONG TERM FUEL TRIM
* Access LONGFT1 PID using NGS tester.
* Compare it with FREEZE FRAME DATA recorded at Step1.
* Is it decreased?
Yes Engine is driven under rich condition. Go to next step.
No Engine is driven under lean condition. Go to Step 10.
7 INSPECT FUEL LINE PRESSURE (EXCESSIVE FUEL LINE PRESSURE)
* Turn ignition key to OFF.
* Inspect fuel line pressure.
FUEL LINE PRESSURE INSPECTION [ZM]
* Is fuel line pressure more than 150 kPa {1.5 kgf/cm2 , 22 psi} ?
Yes Go to Step 9.
No Go to next step.
8 VERIFY VACUUM IS LEADING TO PRESSURE REGULATOR
* Disconnect vacuum hose from pressure regulator.
* Verify that vacuum is felt at opening port of disconnected vacuum hose.
* Is vacuum felt?
Yes Inspect following parts and repair or replace if necessary:
* Fuel pump maximum pressure
* Fuel return pipe for clogging
o If all items above are okay, replace pressure regulator. Then, go to Step 21.
No Verify vacuum hoses are connected correctly.
* If okay, replace PRC solenoid valve. Then go to Step 21.
* If not, reconnect vacuum hoses to correct position. Then go to Step 21.
9 INSPECT PURGE SOLENOID VALVE FOR STUCK OPEN
* Turn ignition key to OFF.
* Disconnect both hoses from purge solenoid valve.
* Blow air through purge solenoid valve.
* Does air blow through?
Yes Replace purge solenoid valve.
No Go to Step 14.
10 INSPECT PCV VALVE OPERATION
* Inspect PCV valve operation.
PCV VALVE INSPECTION [ZM]
* Is PCV valve okay?
Yes Go to next step.
No Replace PCV, then go to Step 21.
11 INSPECT FUEL LINE PRESSURE (LOW FUEL LINE PRESSURE)
* Turn ignition key to OFF.
* Inspect fuel line pressure.
FUEL LINE PRESSURE INSPECTION [ZM]
* Is fuel line pressure more than 150 kPa {1.5 kgf/cm2 , 22 psi} ?
Yes Go to Step 14.
No Go to next step.
12 INSPECT FUEL PUMP MAXIMUM PRESSURE
* Stop engine.
* Turn ignition key to ON (Engine OFF).
* Perform fuel pump maximum pressure test.
Fuel Pump Maximum Pressure Inspection
* Is fuel pump maximum pressure within 450--630 kPa {4.5--6.5 kgf/cm2 , 64--92 psi} ?
Yes Go to next step.
No Inspect fuel pump circuit for open or poor connection.
* Repair or replace suspected circuit.
* If circuit is okay, replace fuel pump.
Then go to Step 21.
13 INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DELIVERY PUMP
* Visually inspect fuel line for any leakage.
* Is any fuel leakage found?
Yes Replace suspected fuel line, then go to Step 21.
No Inspect fuel filters for following:
* Restriction or clogging at fuel filter (high-pressure)
* Foreign material or stain inside fuel filter (low-pressure)
o If restriction or clogging is found at fuel filter (high-pressure), replace fuel filter (high-pressure).
o If foreign material or stain is found inside fuel filter (low-pressure), clean fuel tank and fuel filter (low-pressure).
o If all items above are okay, replace pressure regulator. Then, go to Step 21.
14 CHECK IGNITION COIL OPERATION AND HIGH-TENSION LEAD WITH TIMING LIGHT
* Verify blinking condition on each cylinder using timing light at idle.
* Do all cylinders show blinking condition?
Yes Go to Step 18.
No Go to next step.
15 CHECK HIGH-TENSION LEADS OF NO BLINKING CYLINDER
* Turn ignition key to OFF.
* Inspect high-tension leads for installation condition, corrosion on terminal, open lead and damaged cover.
* Is condition of high-tension lead okay?
Yes Go to next step.
No Replace faulty high-tension lead, then go to Step 21.
16 INSPECT POWER SUPPLY TERMINAL AT IGNITION COIL CONNECTOR
* Disconnect ignition coil connector.
* Turn ignition key to ON (Engine OFF).
* Measure voltage between ignition coil connector terminal D (harness-side) and body ground.
* Is voltage reading B+ ?
Yes Go to next step.
No Check for open circuit between ignition coil connector and ignition switch.
Repair or replace wiring harness, then go to Step 21.
17 INSPECT IGNITION COIL RESISTANCE
* Check ignition coil resistance.
IGNITION COIL INSPECTION
* Is coil resistance okay?
Yes Go to next step.
No Replace ignition coil, then go to Step 21.
18 INSPECT ENGINE COMPRESSION
* Inspect engine compression.
COMPRESSION INSPECTION [ZM]
* Is it okay?
Yes Go to next step.
No Implement engine overhaul for repairs, then go to next step.
19 INSPECT FUEL INJECTOR OPERATION
* Turn ignition key to OFF.
* Inspect injector.
FUEL INJECTOR INSPECTION [ZM]
* Is injector okay?
Yes Go to next step.
No Replace injector, then go to Step 21.
20 INSPECT SEALING OF ENGINE COOLANT PASSAGE
WARNING:
* Removing radiator cap when radiator is hot is dangerous. Scalding coolant and steam may shoot out and cause serious injury.
* When removing radiator cap, wrap a thick cloth around and turn it slowly.
* Remove radiator cap.
* Implement procedure to bleed air from engine coolant, then run engine at idle.
* Is there any small bubble which makes engine coolant white at filling opening?
NOTE:
o Large bubbles are normal since they are remaining air coming out from engine coolant passage.
Yes Air gets in from poor sealing to head gasket or other areas between combustion chamber and engine coolant passage.
Repair or replace faulty parts, then go to next step.
No Go to next step.
21 VERIFY TROUBLESHOOTING OF DTC P1170 COMPLETED
* Make sure to reconnect all disconnected connectors.
* Turn ignition key to ON (Engine OFF).
* Clear DTC from memory using NGS tester generic OBD-II function.
* Start engine.
* Access ECT and RPM PIDs using NGS.
* Make sure that ECT PID is above 80 C {176 F} .
* Increase and keep engine speed above 1,500 rpm for at least 1 minute .
* Is pending code of same DTC present?
Yes Replace or reprogram PCM. Then go to next step.
No Go to next step.
22 VERIFY AFTER REPAIR PROCEDURE
* Perform "After Repair Procedure".
AFTER REPAIR PROCEDURE [ZM]
* Is there any DTC present?
Yes Go to applicable DTC inspection.
DTC TABLE [ZM]
No Troubleshooting completed.
DTC P1142 [ZM] DTC P1250 [ZM]
