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HOMESERVICE MANUALSMAZDA2006B4000 BASE, AUTOMATICREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE SYMPTOM TROUBLESHOOTING - (5 OF 5)GENERAL TEST INDEXGENERAL PINPOINT TEST 7: PCM POWER RELAY
2006 Mazda B4000 Base, Automatic

General Pinpoint Test 7: Pcm Power Relay

2006 Mazda B4000 Base, AutomaticSECTION General Pinpoint Test 7: Pcm Power Relay
GENERAL PINPOINT TEST 7: PCM POWER RELAY

PINPOINT TEST 7 POSITIVE CRANKCASE VENTILATION PCV SYSTEM
STEP INSPECTION ACTION
1 CHECK VPWR CIRCUIT RESISTANCE
  • Disconnect: idle air control (IAC) valve.
  • Disconnect: WDS or equivalent tester from DLC.
  • Disconnect: powertrain control module (PCM) power relay.
  • Measure resistance of VPWR circuit (R) between IAC valve connector 0140-01 and PCM power relay connector.
  • Is resistance less than 5.0 ohms? 
 Yes Connect IAC valve.
Go to next step.
No Repair open VPWR circuit (R) between the PCM power relay and the splice to the IAC valve.
Restore vehicle.
Rerun quick test.
See PCM QUICK TEST .
2 CHECK B+ AND IGN START/RUN VOLTAGE TO PCM POWER RELAY
  • Measure B+ circuit (Y) voltage at the PCM power relay connector.
  • Key ON, Engine OFF (KOEO).
  • Measure IGN START/RUN circuit (T/B) voltage at PCM Power Relay connector.
  • Are both voltages greater than 10.5 volts?
 Yes Go to next step.
No Key OFF.
Repair open in B+ (Y) or IGN START/RUN (T/B) circuit, verify condition of PCM diode.
Restore vehicle.
Rerun quick test.
See PCM QUICK TEST .
3 CHECK GROUND CIRCUIT TO POWER RELAY
  • Measure voltage between B+ (Y) circuit and ground (B/W) circuit at PCM power relay connector.
  • Key OFF.
  • Is the voltage greater than 10.5 volts? 
 Yes Replace PCM power relay.
Restore vehicle.
Rerun quick test.
See PCM QUICK TEST .
No Repair open ground circuit.
Restore vehicle.
Rerun quick test.
See PCM QUICK TEST .
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.