Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.

KOEO/KOER DTC P1460: Verify ACCS PID Is Off

If Continuous Memory DTC P1460 is present, go to step 8 . For A/C always ON, see TEST NO. 4: A/C ALWAYS ON under TROUBLE SHOOTING in MANUAL A/C-HEATER SYSTEMS - B2300, B3000 & B4000 article in AIR-CONDITIONING & HEATING. Verify A/C and defrost were off during KOEO/KOER Self-Tests. If vehicle is not equipped with A/C, the ACCR circuit is not used and DTC P1460 may be ignored. Start engine. Ensure A/C and defroster are off. Using scan tool, select Diagnostic Data Link. Select PCM. Select PID/Data Monitor and Record. Access and observe A/C Control Signal (ACCS) PID. If ACCS PID is off, turn ignition off. Go to next step. If ACCS PID is on, turn ignition off. Go to step 2 in DTC P1464: A/C CONTROL SIGNAL MALFUNCTION to check A/C circuits for short to power.

Check For VPWR To A/C Clutch Relay

Disconnect A/C clutch relay. With KOEO, measure voltage of VPWR circuit between A/C clutch relay harness connector and chassis ground. See Fig 1 . 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. See WIRING DIAGRAMS article. Reconnect A/C clutch relay. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn off ignition. Go to step 10 .

Fig 1: Identifying A/C Clutch Relay Circuits
Courtesy of MAZDA MOTORS CORP.

Check A/C Clutch Relay

Turn ignition off. Reference pin numbers molded on A/C clutch relay. Measure resistance between A/C clutch relay terminals No. 1 and 2. Resistance should be 40-120 ohms. Check for continuity between A/C clutch relay terminals No. 3 and 4. Continuity should be present. Check for continuity between A/C clutch relay terminals No. 3 and 5. Continuity should not be present. If all measurements are okay, go to next step. If any measurement is not okay, replace faulty A/C clutch relay. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10 .

Check A/C Clutch Circuit For Short To Power In Harness

Turn ignition off. Disconnect PCM connector. Install breakout box, leaving PCM disconnected. With KOEO, measure voltage between breakout box terminal No. 69 (ACCR circuit) and chassis ground. Turn ignition off. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to power. See WIRING DIAGRAMS article. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10 .

Check ACCR Circuit For Short To Ground In Harness

Disconnect scan tool from DLC. Measure resistance of ACCR circuit (Pink/Yellow wire) between A/C clutch relay harness connector and ground. See Fig 1 . If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short circuit. See WIRING DIAGRAMS article. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10 .

Check ACCR Circuit Continuity

Measure resistance of ACCR circuit (Pink/Yellow wire) between breakout box terminal No. 69 and A/C clutch relay harness connector. See Fig 1 . If resistance is less than 5 ohms, replace faulty PCM. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10 . If resistance is 5 ohms or more, repair open circuit. See WIRING DIAGRAMS article. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10 .
NOTE: If vehicle is not equipped with A/C, ACCR circuit is not used and DTC P1460 may be ignored.

Continuous Memory DTC P1460: Check ACCR Circuit For Intermittent Short To Ground

With KOEO, check ACCR circuit for short to ground while shaking, wiggling and bending ACCR circuit between PCM and A/C clutch relay. Lightly tap on A/C clutch relay (to simulate road shock). A/C clutch will click on when a fault is indicated. If a fault is not indicated, go to next step. If a fault is indicated, repair wiring harness as necessary. Turn ignition off. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10 .

Check ACCR Circuit For Intermittent Open Or Short To Power

Using scan tool, select Diagnostic Data Link. Select PCM. Select Active Command Modes. Access Output Test Mode. Check ACCR circuit for open or short to power while shaking, wiggling and bending ACCR circuit between PCM and A/C clutch relay. Shake, wiggle and bend VPWR circuit (Pink/Yellow wire) to A/C clutch relay. See Fig 1 . Lightly tap on A/C clutch relay (to simulate road shock). A/C clutch will click off when a fault is indicated. If a fault is indicated, turn ignition off. Repair open or short circuit. See WIRING DIAGRAMS article. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to next step. If a fault is not indicated, unable to duplicate or identify fault at this time. See INTERMITTENT under SYSTEM TESTS.

Verify Trouble Shooting Of DTCs Completed

Reconnect all electrical connectors. Using scan tool, clear DTC memory. Using scan tool, retrieve DTCs. See QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM and repeat QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, trouble shooting is complete.