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Home >> Mazda >> 2001 >> Tribute ES, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> System Tests >> Test DS: Air Conditioning Pressure Sensor >> Diagnostic Aids

Diagnostic Aids

Perform this test when directed by QUICK TEST. This system test is intended to diagnose:

  1. 1) DTC P1461: Check ACP V PID

    This DTC indicates PCM has detected high voltage in ACP circuit. Possible causes for this fault are:
    • ACP Sensor Circuit Short To PWR
    • ACP Circuit Open
    • Faulty Powertrain Control Module (PCM)
    • ACP Circuit Shorted To VREF Or SIG RTN
    • Faulty ACP Sensor

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, select ACP V PID from PID/DATA MONITOR & RECORD menu. If ACP V PID voltage is 4.9 volts or more, go to next step. If ACP V PID voltage is less than 4.9 volts, fault is unable to be duplicated at this time. Go to step  18).

  2. 2) Check Voltage Between VREF & SIG RTN Circuits To ACP Sensor

    Turn ignition switch to OFF position. Disconnect ACP sensor harness connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between ACP sensor harness connector SIG RTN and VREF terminals. See Fig 1. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, VREF is out of range or SIG RTN circuit is open. Go to TEST C, step  1).
    Fig 1: Identifying ACP Sensor Circuits & Connector Terminals
    G00013263Courtesy of FORD MOTOR CO.

  3. 3) Induce Opposite ACP Signal

    Turn ignition switch to ON position. Using scan tool, select ACP V PID from PID/DATA MONITOR & RECORD menu. If ACP V PID voltage is 4.9 volts or more, go to next step. If ACP V PID voltage is less than 4.9 volts, replace ACP sensor. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .

  4. 4) Check ACP Circuit For Short To VREF

    Turn ignition switch to OFF position. Disconnect scan tool from DLC. Disconnect PCM connector(s). Using a DVOM, measure resistance between ACP sensor harness connector ACP and VREF terminals. See Fig 1. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to VREF in ACP circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .

  5. 5) Check ACP Circuit For Short To Power

    Turn ignition switch to ON position. Using a DVOM, measure voltage between ACP sensor harness connector ACP terminal and negative battery terminal. See Fig 1. If voltage is less than one volt, replace PCM. If voltage is one volt or more, repair short to VPWR in ACP circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 5) to step 10). No test procedures have been omitted.

  6. 10) DTC P1462: Check ACP V PID

    This DTC indicates PCM has detected low voltage in ACP circuit. Possible causes for this fault are:
    • Faulty ACP Sensor
    • Open Or Shorted Circuit
    • Faulty Powertrain Control Module (PCM)

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool select ACP V PID from PID/DATA MONITOR & RECORD menu. If ACP V PID voltage is .15 volt or less, go to next step. If ACP V PID voltage is more than .15 volt, fault is unable to be duplicated at this time. Go to step  18).

  7. 11) Check Voltage Between VREF & SIG RTN Circuits To ACP Sensor

    Turn ignition switch to OFF position. Disconnect ACP sensor harness connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between ACP sensor harness connector SIG RTN and VREF terminals. See Fig 1. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, VREF is out of range. Turn ignition switch to OFF position and go to TEST C, step  1).

  8. 12) Induce Opposite ACP Signal

    Turn ignition switch to OFF position. Connect a jumper wire between ACP sensor harness connector ACP and VREF terminals. See Fig 1. Turn ignition switch to ON position. Using scan tool, select ACP V PID from PID/DATA MONITOR & RECORD menu.
    NOTE: If communication link error is displayed, remove jumper wire and go to next step.

    If ACP V PID voltage is 4 volts or less, go to next step. If ACP V PID voltage is more than 4 volts, replace ACP sensor. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .

  9. 13) Check ACP Circuit For Short To PWR GND Or SIG RTN

    Turn ignition switch to OFF position. Disconnect scan tool from DLC. Disconnect PCM connector(s). Using a DVOM, measure resistance between ACP sensor harness connector ACP and SIG RTN terminals. See Fig 1. Using a DVOM, measure resistance between ACP sensor harness connector ACP terminal and negative battery terminal. 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 ground in affected circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .

  10. 14) Check ACP Circuit For Open

    Using a DVOM, measure resistance of ACP circuit between PCM harness connector terminal and ACP sensor harness connector terminal. See Fig 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in ACP circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .

  11. 15) Check For A/C Clutch Engagement

    Turn ignition switch to OFF position. Reconnect ACP sensor. Turn ignition switch to ON position. Turn A/C switch to ON position while listening for A/C clutch engagement. If A/C clutch engages when A/C is turned on, replace PCM. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST . If A/C clutch does not engage when A/C is turned on, go to next step.

  12. 16) Check A/C System Refrigerant Charge

    Reconnect all components. Connect A/C manifold gauge set and check if A/C system has correct refrigerant charge. Service A/C system as necessary. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST . If A/C system has correct refrigerant charge, replace PCM. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 16) to step 18). No test procedures have been omitted.

  13. 18) Check For Intermittent ACP Circuit Fault

    Turn ignition switch to ON position. Using scan tool, select ACP V PID from PID/DATA MONITOR & RECORD menu. While observing ACP V PID, lightly tap on ACP sensor and wiggle sensor connector and wiring harness to simulate road shock. A fault is indicated by a sudden change of ACP V PID voltage. If fault is indicated, isolate and repair as necessary. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST . If no faults are indicated, fault is unable to be duplicated at this time. Go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 18) to step 20). No test procedures have been omitted.

  14. 20) Continuous Memory DTC P1463: Verify A/C Clutch Can Disengage

    This DTC indicates PCM has detected that ACP sensor did not detect sufficient change in A/C system pressure when A/C switch was turned to ON position. Possible causes for this fault are:
    • A/C System Mechanical Malfunction
    • ACP Or VREF Open Circuit
    • Faulty ACP Sensor
    • A/C System Electrical Malfunction (Non-EEC Related)
    • A/C Clutch Continuous Engagement

    Ensure A/C and defroster are off. Start engine and allow to idle. Verify A/C clutch is disengaged. If A/C clutch is disengaged, go to next step. If A/C clutch did not disengage, check A/C clutch circuit. Diagnose by symptom. See SYMPTOMS in TROUBLE SHOOTING - NO CODES article. Repair as necessary.

  15. 21) Check Power & Ground To A/C Clutch

    Turn ignition switch to OFF position. Disconnect A/C cycling switch. Connect a jumper wire between A/C cycling switch harness connector terminals. Disconnect A/C clutch. Connect non-powered test light between power and ground terminals at A/C clutch harness connector. Start engine and allow to idle. Turn A/C switch on. Monitor test light for 15 seconds. If test light comes on or A/C clutch can be heard clicking, go to next step. If test light does not come on or A/C clutch cannot be heard clicking, see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.

  16. 22) Check ACP V PID

    Start engine and allow to idle. Ensure A/C is off. Using scan tool, access ACP V PID from PID/DATA MONITOR & RECORD menu. Note A/C V PID voltage reading. Monitor ACP V PID value and turn A/C on. Note ACP V PID voltage reading within 5 seconds of A/C clutch engagement and compare measurement with ACP V PID measurement noted previously. If ACP V PID voltage change is .3 volt or less, go to next step. If ACP V PID voltage change is more than .3 volt, ACP sensor and PCM can detect change in A/C pressure. If directed here by DTC P1463, diagnose by symptom. See SYMPTOMS in TROUBLE SHOOTING - NO CODES article. Repair as necessary. For all others, see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. Check A/C system for proper operation and repair as necessary.

  17. 23) Check A/C System Pressure & Pressure Change

    Turn ignition switch to OFF position. Reconnect all components. Connect A/C manifold gauge set. Start engine and allow to idle. With A/C off, note high pressure measurement. Turn A/C on. Wait 5 seconds and note high pressure measurement. If high pressure measurement changes more than 30 psi (207 kPa) within 5 seconds of clutch engagement, go to next step. If high pressure measurement does not change more than 30 psi (207 kPa) within 5 seconds of clutch engagement, service A/C system as necessary. See appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. After servicing A/C system, start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .

  18. 24) Check Voltage Between VREF & SIG RTN Circuit To ACP Sensor

    Turn ignition switch to OFF position. Disconnect ACP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between ACP sensor harness connector SIG RTN and VREF terminals. See Fig 1. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, VREF is out of range. Go to TEST C, step  1).

  19. 25) Check ACP Circuit For Open In Sensor

    Turn ignition switch to OFF position. Ensure ACP sensor harness connector is disconnected. Disconnect PCM connector(s). Using a DVOM, measure resistance of ACP circuit between PCM harness connector terminal and ACP sensor harness connector terminal. See Fig 1. If resistance is less than 5 ohms, replace ACP sensor. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST . If resistance is 5 ohms or more, repair open in ACP circuit. Start engine and turn A/C on for 15 seconds. Turn A/C off and repeat QUICK TEST .
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