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Home >> Mazda >> 2002 >> Tribute LX, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 69 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0112, DTC P0113, DTC P0116, DTC P0117, DTC P0118, DTC P0125, DTC P0128, DTC P0298, DTC P1112, DTC P1116, DTC P1117, DTC P1285, DTC P1288, DTC P1289, DTC P1290 Or DTC P1299 >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Mazda Tribute. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If any DTCs are present, proceed as follows:
    • For DTCs P1116 or P1288, go to next step.
    • For DTC 1285 (if not a cooling system malfunction), go to step  4.
    • For KOEO or KOER DTCs P0113 or P0118, go to step  6.
    • For DTCs P1289 or P1290, go to step  10.
    • For KOEO or KOER DTC P0112 or P0117, go to step  11.
    • For Continuous Memory (without KOEO and KOER DTCs) DTCs P0112, P0113, P0117, P0118, P1112, P1117, P1289 or P1290, go to step  14.
    • For DTCs P0125 or P0128, go to step  16.
    • For DTC P1299, go to step  17.
  2. DTC P1116 Or DTC P1288: Check Operation Of ECT/CHT Sensor -  Start engine and run at 2000 RPM until engine temperature becomes stabilized. If vehicle does not start, go to step  4. If vehicle stalls, refer to SYMPTOM DIAGNOSIS in TROUBLE SHOOTING - NO CODES article. Ensure upper radiator hose is hot and pressurized. Run KOEO self-test. See KOEO & KOER SELF-TEST . If DTC P1116 or P1288 is present, go to next step. If DTC P1116 or P1288 is not present, engine was not in closed loop operating conditions. Repair any other DTCs and repeat QUICK TEST  under SELF-DIAGNOSTIC SYSTEM.
  3. Check VREF Circuit Voltage At TP Sensor -  Turn ignition off. Disconnect TP sensor 3-pin harness connector. With KOEO, measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). If voltage reading is 4-6 volts, go to next step. If voltage reading is not as specified, reconnect disconnected connectors and go to VEHICLE REFERENCE VOLTAGE  testing under SYSTEM TESTS.
  4. Check Resistance Of Temperature Sensor With Engine Off -  Turn ignition off. Reconnect TP sensor 3-pin harness connector. Disconnect ECT or CHT sensor 2-pin harness connector. Measure resistance between ECT/CHT sensor terminals. See Fig 1 or Fig 2 . See ECT & MAF/IAT SENSOR SPECIFICATIONS  or CHT SENSOR SPECIFICATIONS  table. If resistance reading is within specification, for ECT/CHT sensor with a No Start: Do not service DTCs P1116 or P1288 at this time. Go to SYMPTOM DIAGNOSIS in TROUBLE SHOOTING - NO CODES article. For symptoms of cooling fan problems, overheating and lack of heat: Do not service DTCs P1116 or P1288 at this time. Repair other DTC(s). If no other DTC(s) is present, go to appropriate COOLING SYSTEMS article in ENGINES. For all other DTCs, go to next step. If resistance reading is not within specification, replace ECT/CHT sensor. After repair, go to step  18.
    NOTE: Ensure engine is at operating temperature before taking ECT/CHT readings.
    ECT & MAF/IAT SENSOR SPECIFICATIONS (1)

    Temperature °F (°C) Volts (2) Ohms
    50 (10) 3.51 58,750
    68 (20) 3.07 27,300
    86 (30) 2.60 24,270
    104 (40) 2.13 16,150
    122 (50) 1.70 10,970
    140 (60) 1.33 7700
    158 (70) 1.02 5370
    176 (80) 0.78 3840
    194 (90) 0.60 2800
    212 (100) 0.46 2070
    230 (110) 0.35 1550
    248 (120) 0.27 1180
    (1) Values may differ by as much as 15 percent.
    (2) Measure resistance between sensor terminals.
    CHT SENSOR SPECIFICATIONS

    Temperature °F (°C) Volts (1) Ohms
    -40 (-40) 4.89 965,808
    -22 (-30) 4.81 513,019
    -4 (-20) 4.67 283,664
    14 (-10) 4.45 162,584
    32 (0) 4.14 96,255
    50 (10) 3.73 59,175
    68 (20) 3.26 37,387
    86 (30) 2.74 24,215
    104 (40) 2.23 16,043
    122 (50) 1.76 10,850
    140 (60) 1.36 7487
    158 (70) 1.04 5268
    176 (80) (2) 0.79 Or 3.99 3775
    185 (85) (2) 0.69 Or 3.86 3215
    194 (90) (2) 0.60 Or 3.71 2750
    203 (95) (2) 0.53 Or 3.56 2361
    212 (100) (2) 0.46 Or 3.41 2034
    230 (110) 3.07 1523
    248 (120) 2.74 1155
    266 (130) 2.41 887
    284 (140) 2.10 689
    302 (150) 1.81 542
    320 (160) 1.55 430
    338 (170) 1.33 345
    356 (180) 1.13 279
    374 (190) 0.96 228
    392 (200) 0.82 188
    410 (210) 0.70 155
    428 (220) 0.60 130
    446 (230) 0.51 109
    464 (240) 0.44 92
    482 (250) 0.35 78
    500 (260) 0.33 67
    (1) Measure resistance between cylinder head temperature sensor terminals.
    (2) At this temperature, there is a voltage overlap zone where it is possible to have either a cold end (low voltage) or hot end (high voltage) reading at the same temperature. Either voltage specification listed is correct.
  5. Check Resistance Of Temperature Sensor With Engine Running -  Disconnect suspect temperature sensor. Run engine at 2000 RPM for 2 minutes. Measure resistance between ECT/CHT or IAT sensor terminal and SIG RTN terminal at temperature sensor harness connector. See Figure, Fig 1 or Fig 2 . See ECT & MAF/IAT SENSOR SPECIFICATIONS  or CHT SENSOR SPECIFICATIONS  table. If resistance reading is within specification, replace PCM. After repair, go to step  18. If resistance reading is not within specification, replace suspect ECT/CHT or IAT sensor. After repair, go to step  18.
    Fig 1: Identifying Cylinder Head Temperature (CHT) Sensor Harness Connector Terminals
    G00035652Courtesy of FORD MOTOR CO.
    Fig 2: Identifying Engine Coolant Temperature (ECT) Sensor Circuits & Harness Connector Terminals
    G00013242Courtesy of FORD MOTOR CO.
  6. DTC P0113 Or DTC P0118: Check Voltage Between VREF & SIG RTN -  Turn ignition off. Disconnect TP sensor 3-pin harness connector. Turn ignition on, engine off. Measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). If voltage reading is 4-6 volts, go to next step. If voltage reading is not as specified, reconnect disconnected connectors and go to VEHICLE REFERENCE VOLTAGE  testing under SYSTEM TESTS.
  7. Simulate Opposite Signal To PCM -  Turn ignition off. Disconnect suspect temperature sensor. Connect fused jumper wire between suspect ECT/CHT sensor (Light Green/Red wire) or IAT sensor (Pink/Black wire) harness connector terminal and SIG RTN terminal (Orange wire) at temperature sensor harness connector. Turn ignition on, engine off. If scan tool communication concern is present, disconnect fused jumper wire immediately and go to step  9. Access ECT/CHT V or IAT V PID. If ECT/CHT V or IAT V PID reading is less than 0.2 volt, remove fused jumper wire and replace suspect sensor. After repair, go to step  18. If voltage reading is not as specified, remove fused jumper wire and go to next step.
  8. Check Temperature Sensor Signal & SIG RTN Circuits For Open In Harness -  Turn ignition off. Disconnect PCM 104-pin harness connector. Disconnect suspect temperature sensor. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance between ECT/CHT sensor (Light Green/Red wire) or IAT sensor (Pink/Black wire) harness connector terminal and breakout box terminal No. 38 (ECT/CHT sensor) or terminal No. 39 (IAT sensor). Measure resistance of Orange wire between SIG RTN harness connector terminal of temperature sensor and breakout box terminal No. 91. If resistance is less than 5 ohms, replace PCM. After repair, go to step  18. If resistance reading is 5 ohms or more, repair open circuit in suspect harness. After repair, go to step  18.
  9. Check Temperature Sensor Signal & SIG RTN Circuits For Open In Harness -  Measure resistance between SIG RTN circuit (Orange wire) at appropriate temperature sensor harness connector terminal and breakout box terminal No. 90 (VREF). See Figure, Fig 1 or Fig 2 . If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step  18. If resistance reading is 10,000 ohms or less, repair short to VREF circuit. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  18.
  10. DTC P1289 Or DTC P1290: Check Voltage Of CHT PID -  Turn ignition on, engine off. Access CHT V PID. If CHT V PID reading is less than 0.2 volt, go to next step. If CHT V PID reading is 0.2 volt or more, go to step  7.
  11. DTC P0112 Or DTC P0117: Simulate Opposite Signal To PCM -  Turn ignition off. Disconnect suspect temperature sensor harness connector. Turn ignition on, engine off. Access ECT V or IAT V PID. If ECT V or IAT V PID reading is 4.6 volts or less, go to next step. If ECT V or IAT V PID reading is more than 4.6 volts, replace suspect temperature sensor. After repair, go to step  18.
  12. Check VREF Circuit Voltage To TP Sensor -  Turn ignition off. Disconnect TP sensor 3-pin harness connector. Turn ignition on, engine off. Measure voltage between VREF (Brown/White wire) and SIG RTN (Gray/Red wire) at TP sensor harness connector. See Figure. If voltage is 4-6 volts, there is sufficient VREF voltage. Reconnect TP sensor. Go to next step. If voltage is not 4-6 volts, reconnect all electrical connections. Go to VEHICLE REFERENCE VOLTAGE  testing under SYSTEM TESTS.
  13. Check Signal Circuit For Short To Ground -  Turn ignition off. Disconnect suspect temperature sensor. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance between breakout box terminal No. 38 (ECT/CHT sensor ) or terminal No. 39 (IAT sensor) and terminal No. 24 (PWR GND). See Figure, Fig 1 or Fig 2 . Record reading. Measure resistance between breakout box terminal No. 38 (ECT/CHT sensor) or terminal No. 39 (IAT sensor) and terminal No. 91 (SIG RTN). Record reading. If each resistance reading is more than 10,000 ohms, replace faulty PCM. After repair, go to step  18. If each resistance reading is 10,000 ohms or less, repair short circuit. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  18.
  14. DTCs P0112, P0113, P0117, P0118, P1112, P1117, P1289 Or P1290: Intermittent Check -  Turn ignition on, engine off. Monitor ECT/CHT V PID or IAT V PID. While observing PID, tap on suspect sensor to simulate road shock and wiggle sensor connector. If any large change in temperature reading is not present, go to next step. If any large change in temperature reading is present, disconnect sensor harness connector and inspect. If sensor harness connector is okay, replace suspect sensor. After repair, go to step  18.
  15. Check Engine Wiring Harness -  Turn ignition on, engine off. While observing ECT V PID, CHT V PID or IAT V PID, grasp harness close to suspect sensor. Wiggle, shake and bend harness back to PCM. If any large change in temperature reading is not present, go to step  18. If any large change in temperature reading is present, isolate and repair fault as necessary. After repair, go to step  18. For Continuous Memory DTCs P1112 and P1117, perform COMPREHENSIVE COMPONENT MONITOR REPAIR VERIFICATION DRIVE CYCLE  under MONITOR REPAIR VERIFICATION DRIVE CYCLES.
  16. DTC P0125 Or P0128 Indicates Excessive Time To Enter Closed Loop Fuel Control -  Check engine coolant level. If coolant level is okay, go to appropriate COOLING SYSTEMS article in ENGINES and repair cooling system malfunction as necessary. If coolant level is not okay, fill to proper level. After repair, go to step  18. For Continuous Memory DTCs P1112 and P1117, perform COMPREHENSIVE COMPONENT MONITOR REPAIR VERIFICATION DRIVE CYCLE  under MONITOR REPAIR VERIFICATION DRIVE CYCLES.
  17. DTC P1299 Indicates An Engine Overheat Condition Occurred -  Check engine coolant level. If coolant level is okay, perform to ENGINE OVERHEATS symptom testing in appropriate COOLING SYSTEMS article in ENGINES and repair cooling system malfunction as necessary. If coolant level is not okay, refer to LOSS OF COOLANT symptom testing in appropriate COOLING SYSTEMS article in ENGINES. Repair cooling system leak.
  18. Verify Trouble Shooting Of DTCs Completed -  Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. See CLEARING CODES  under SELF-DIAGNOSTIC SYSTEM. Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace PCM. After repair repeat QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If no other DTCs are present, trouble shooting is complete.
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