Mazda MX-6 1998, Workshop Manual, Page: 697 / 1282

TROUBLESHOOTING [LA4A-EL]
STEP
INSPECTION
ACTION
DA2 CHECK CONTINUITY OF TR SWITCH
HARNESS CIRCUITS
• Key off.
Caution
• Do not attempt to pry on TR switch
connector. This will damage the connector
and could result in a transaxle concern.
Press button and pull up on the transaxle
connector, (vehicle harness side)
• Disconnect TR switch connector.
• Inspect for damaged or pushed out pins,
corrosion, loose wires, etc.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion, loose wires, etc.
service as required.
• Install breakout box, leave PCM disconnected.
• Refer to connector of TR switch.
p TR Switch Connector Component
• Hold the vehicle harness close to the sensor
connector. Wiggle, shake and bend small
section of wiring harness while working toward
PCM.
• Measure resistance between PCM test pin 91
at the breakout box and the SIG RTN circuit at
the TR switch connector
• Measure resistance between PCM test pin 64
at the breakout box and TR signal circuit at the
TR switch connector
• Is each resistance less than 5.0 ohms?
Yes Service as required.
No Repair or replace, harness and/or connector.
Pinpoint test E
DTC P1747
P1746
Electronic pressure control (EPC) solenoid circuit failure, shorted to ground or open
Open powertrain control module (PCM) output driver
DESCRIPTION
This Pinpoint Test is intended to diagnose the following components:
• Transaxle Wiring Harness, EPC, EPC power circuit
• PCM
POSSIBLE
CAUSE
• .Engine: Performance
• Electrical: Battery, input sensors, wiring harness
• Transaxle: Internal transaxle components, cooling
STEP INSPECTION ACTION
E1 ELECTRONIC DIAGNOSTICS
• Check the solenoid body connector is fully
seated, terminals are fully engaged in the
connector and in good condition before
proceeding.
• Connect NGS tester.
• Perform key on engine off (KOEO) test until
continuous memory DTC have been displayed.
• Enter output test mode EPC V.
tr 0 1 -0 1 A ENGINE ON-BOARD DIAGNOSIS
[FS]
• Select EPC V PID
• Cycle EPC solenoid 0— 8 V/12 V by selecting
STOP/START mode
• Does EPC V PID cycle?
Yes
Go to E2.
No If vehicle did not enter output state (Diagnostic test mode
(DTM)).
p r 01-01A ENGINE ON-BOARD DIAGNOSIS [FS]
0 5 -0 1 A -2 2