Mazda CX-7 2007 Workshop Manual page 1426

SYMPTOM TROUBLESHOOTING [INSTRUMENT CLUSTER]
NO. 8 TACHOMETER INDICATION IS DEFECTIVE[INSTRUMENT CLUSTER]
8 Tachometer indication is defective
• PCM malfunction
• Instrument cluster malfunction
• Connector or pin malfunction
POSSIBLE
• Short circuit in wiring harness between CAN-L, CAN-H and GND
CAUSE
• Open circuit in CAN wiring harness (CAN-L, CAN-H)
• CAN wiring harness (CAN-L, CAN-H) short each other
Diagnostic procedure
STEP
• Start the engine.
1
— Does the tachometer needle move
smoothly?
— Does the tachometer needle indicate
correct engine speed?
• Inspect the DTC for the instrument cluster
2
ON-BOARD DIAGNOSTIC SYSTEM.
• Has DTC U2023 been recorded in memory?
• Inspect the FREEZE FRAME DATA for DTC
3
U2023.
• Has the speedometer fall-safe function been
requested?
• Start the instrument cluster input/output
4
check mode.
• Inspect the tachometer using the check code
13.
• Is the tachometer normal?
• Disconnect the negative battery cable.
5
• Measure the resistance between the DLC-2
terminals F and E.
• Is the resistance 54— 66 ohms?
• Disconnect the negative battery cable.
6
• Inspect the DLC-2 terminals F and E for
short to power supply or GND.
• Is there any malfunction?
• Turn the ignition switch off.
7
• Inspect the instrument cluster connector
terminals for poor connection (such as
damaged/pulled-out pins, and corrosion).
• Are the terminals normal?
• Disconnect the negative battery cable.
8
• Measure the resistance between the
instrument cluster connector terminals 2R
and 2T.
• Is the resistance 114— 126 ohms?
2W 2U 2S 2Q 2O
2X 2V 2T 2R 2P
End Of Sie
09-03C–8
INSPECTION
2M 2K 2I 2G 2E 2C 2A
2N 2L 2J 2H 2F 2D 2B
Yes Troubleshooting completed.
No Go to the next step.
Yes Go to the next step.
No Go to Step 4.
Yes Inspect the DTC for the PCM.
(See 01-02-7 ON-BOARD DIAGNOSTIC TEST[L3 WITH
TC].)
No Go to the next step.
Yes Inspect the PCM or connectors.
No Replace the instrument cluster.
Yes Go to the next step.
No Go to Step 7.
Yes Inspect the wiring harness and CAN system-related module.
Repair or replace the malfunctioning part.
No Replace the instrument cluster.
Yes Go to the next step.
No Repair or replace the terminal.
Yes Inspect the wiring harness and CAN system-related module.
Repair or replace the malfunctioning part.
No Replace the instrument cluster.
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