Home/Mazda/MX-5/Mazda MX-5 NC (2005-2008)/Repair manual/Communication Devices/On-Board Diagnostic (Multiplex Communication System): Other
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On-Board Diagnostic (Multiplex Communication System): Other Mazda MX-5 NC

Outline

  1. If the controller area network (CAN) system is malfunctioning, read the DTCs of the following modules, using the WDS or equivalent to determine the malfunctioning system. PCM TCM DSCHU/CM ABSHU/CM Keyless control module Steering angle sensor Instrument cluster

Flow Chart

  1. Use «FLOW CHART REFERENCE TABLE»(ref-244451-S10860988942006092400000) to verify the cause of the trouble.
STEPINSPECTIONACTION
1INSPECT DTC INDICATION Using the WDS or equivalent, inspect if DTCs are displayed for the following module: PCM TCM DSC HU/CM ABS HU/CM Keyless control module Steering angle sensor Instrument cluster Are any DTCs displayed?YesGo to the next step.
NoGo to Step 5.
2INSPECT CAN SYSTEM-RELATED DTC Are any DTCs other than the following displayed? U0073 U0100 U0101 U0121 U0155 U0214 U0323 U1900 U2023 U2516YesRepair the malfunctioning part by following the related DTC inspection. Go to the next step.
NoGo to the next step.
3INSPECT CAN SYSTEM-RELATED DTC Are any of the following DTCs displayed? PCM: U0073, U0101, U0121, U0155 TCM: U0073, U0100 DSC HU/CM: U0073, U0100, U0101, U0155, U1900, U2023 ABS HU/CM: U0073, U1900, U2023 Keyless control module: U0073, U0100, U0323, U2023 Steering angle sensor: U1900, U2516 Instrument cluster: U0073, U0100, U0101, U0121, U0214YesRepair the malfunctioning part by following the DTC inspection. Go to the next step.
NoTroubleshooting completed.
4VERIFY TROUBLESHOOTING COMPLETED Clear the DTC from the CAN system-related modules using the WDS or equivalent. Start the engine. Are any of the CAN related DTCs displayed?YesGo back to Step 3.
NoTroubleshooting completed.
5INSPECT COMMUNICATION CONDITION Is there a response from the following modules? PCM TCM DSC HU/CM ABS HU/CM Keyless control module Steering angle sensor Instrument clusterYesTroubleshooting completed.
NoGo to the next step.
6INSPECT MODULES THAT DO NOT RESPOND Inspect the power supply and the ground circuit for any units that do not respond. Are they normal?YesGo to the next step.
NoRepair the malfunctioning part, then go back to Step 1.
7INSPECT CONNECTOR AND WIRING HARNESS BETWEEN MODULES THAT DO NOT RESPOND AND DLC-2 Turn the ignition switch to the LOCK position. Inspect the wiring harness and connector between any module that does not respond and the DLC-2. PCM-DLC-2 1AM-F 1AI-E TCM-DLC-2 1G-F 1C-E DSC HU/CM-DLC-2 X-F W-E ABS HU/CM-DLC-2 Z-F Y-E Keyless control module-DLC-2 4AA-F 4Z-E Steering angle sensor-DLC-2 E-F F-E Instrument cluster-DLC-2 1J-F 1L-E Is there any malfunction?YesRepair the malfunctioning part, then go back to Step 1.
NoGo to the next step.
8INSPECT WIRING HARNESS Turn the ignition switch to the ON position (Engine off). Measure the voltage between the following terminals. DLC-2 terminals F and GND DLC-2 terminals E and GND Is the voltage 2.0-3.0 V?YesGo to the next step.
NoGo to Step 12.
9INSPECT WIRING HARNESS Turn the ignition switch to the LOCK position. Measure the resistance between the following terminals. DLC-2 terminals F and E Is the resistance 59-65 ohms?YesReplace the modules that do not respond, then go back to Step 1.
NoGo to the next step.
10INSPECT PCM Disconnect the PCM connector. Measure the resistance between following terminals. PCM terminals 1AM and 1AI (part-side) Is the resistance 118-130 ohms?YesGo to the next step.
NoReplace the PCM, then go to the next step.
11INSPECT INSTRUMENT CLUSTER Disconnect the instrument cluster connector. Measure the resistance between the following terminals. Instrument cluster terminals 1J and 1L (part-side) Is the resistance 118-130 ohms?YesGo to next step.
NoReplace the instrument cluster, then go to the next step.
12CLASSIFY WIRING HARNESS MALFUNCTION OR MODULE MALFUNCTION Turn the ignition switch to the LOCK position. Disconnect the connector of any unit that does not respond. (If there are two or more units that do not respond, disconnect only one of the units.) Turn the ignition switch to the ON position. Measure the voltage between the following terminals. DLC-2 terminals F and GND DLC-2 terminals E and GND Is voltage 2.0-3.0 V?YesGo to the next step.
NoRetry this step with other module connector disconnected. If all units that do not respond are disconnected, go to Step 14.
13INSPECT WIRING HARNESS OF ANY UNIT THAT DOES NOT RESPOND Turn the ignition switch to the LOCK position. Inspect for continuity between the following connector terminals of any disconnected unit. PCM-DLC-2 1AM-other terminals 1AI-other terminals TCM-DLC-2 1G-other terminals 1C-other terminals DSC HU/CM-DLC-2 X-other terminals W-other terminals ABS HU/CM-DLC-2 Z-other terminals Y-other terminals Keyless control module-DLC-2 4AA-other terminals 4Z-other terminals Steering angle sensor-DLC-2 E-other terminals F-other terminals Instrument cluster-DLC-2 1J-other terminals 1L-other terminals Is there continuity?YesRepair or replace the wiring harness, then go back to Step 1.
NoReplace the disconnected unit, then go back to Step 1.
14INSPECT CAN RELATED WIRING HARNESS Inspect the related wiring harnesses (CAN_L and/or CAN_H) for the short circuit (to power supply or ground). Is the wiring harness normal?YesRepair or replace the wiring harness, then go back to Step 1.
NoGo back to Step 1.

FLOW CHART REFERENCE TABLE

PCM

  1. Inspect the display of DTC U0101, U0121 and/or U0155, using the WDS or equivalent. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)
  2. Referring to «PCM REFERENCE TABLE»(ref-244451-S37368613532006092400000) , determine the malfunctioning part of the CAN system.
X: Normal -: Communication error
ModuleCommunication statusMalfunction location
DSC HU/CM ABS HU/CMTCMInstrument cluster
PCMWiring harness A PCM
XXWiring harness C TCM
XXWiring harness B DSC HU/CM or ABS HU/CM
XXWiring harness D Wiring harness F Wiring harness H Instrument cluster

PCM REFERENCE TABLE

TCM

  1. Inspect the display of DTC U0100 using the WDS or equivalent. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)
  2. Referring to «TCM REFERENCE TABLE»(ref-244451-S19904337932006092400000) , determine the malfunctioning part of the CAN system.
X: Normal -: Communication error
ModuleCommunication statusMalfunction location
PCM
TCMWiring harness A Wiring harness C TCM PCM

TCM REFERENCE TABLE

DSC HU/CM or ABS HU/CM

  1. Inspect the display of DTC U0100 (DSC), U0101 (DSC), U0155 (DSC), U1900 and/or U2023, using the WDS or equivalent. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)
  2. Referring to «DSC HU/CM OR ABS HU/CM REFERENCE TABLE»(ref-244451-S37009960952006092400000) , determine the malfunctioning part of the CAN system.
X: Normal -: Communication error
ModuleCommunication statusMalfunction location
PCMTCMInstrument cluster
DSC HU/CM or ABS HU/CMWiring harness B DSC HU/CM or ABS HU/CM
XXWiring harness C TCM
XXWiring harness A PCM
XXWiring harness D Wiring harness F Wiring harness H Instrument cluster

DSC HU/CM OR ABS HU/CM REFERENCE TABLE

Keyless Control Module

  1. Inspect the display of DTC U0100, U0323 and/or U2023 using the WDS or equivalent. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)
  2. Referring to «KEYLESS CONTROL MODULE REFERENCE TABLE»(ref-244451-S10993230572006092400000) , determine the malfunctioning part of the CAN system.
X: Normal -: Communication error
ModuleCommunication statusMalfunction location
PCMInstrument cluster
Keyless control moduleWiring harness E Keyless control module
XWiring harness A Wiring harness D PCM
XWiring harness F Wiring harness H Instrument cluster

KEYLESS CONTROL MODULE REFERENCE TABLE

Steering Angle Sensor

  1. Inspect the display of DTC U1900 using the WDS or equivalent. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)
  2. Referring to «STEERING ANGLE SENSOR REFERENCE TABLE»(ref-244451-S36699800292006092400000) , determine the malfunctioning part of the CAN system.
X: Normal -: Communication error
ModuleCommunication statusMalfunction location
DSC HU/CM
Steering Angle SensorWiring harness B Wiring harness D Wiring harness F Wiring harness G DSC HU/CM Steering Angle Sensor

STEERING ANGLE SENSOR REFERENCE TABLE

Instrument Cluster

  1. Inspect the display of DTC U0100, U0101, U0121, and/or U0214, using the WDS or equivalent. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)
  2. Referring to «INSTRUMENT CLUSTER REFERENCE TABLE»(ref-244451-S42197684992006092400000) , determine the malfunctioning part of the CAN system.
X: Normal -: Communication error
ModuleCommunication statusMalfunction location
PCMTCMDSC HU/CM ABS HU/CMKeyless control module
Instrument clusterWiring harness F Wiring harness H Instrument cluster
XWiring harness D
XXXWiring harness A PCM
XXXWiring harness C TCM
XXXWiring harness B DSC HU/CM or ABS HU/CM
XXXWiring harness E Keyless control module

INSTRUMENT CLUSTER REFERENCE TABLE

Repair Procedure

  1. Inspect the connector of malfunctioning module. If there is any malfunction, repair or replace the connector.
  2. Inspect the malfunctioning wiring harnesses as follow: If there is any malfunction, repair or replace the wiring harnesses. If there is no malfunction, replace the malfunctioning module. Short to GND Short to power supply Twisted pair short each other Open circuit
  3. Make sure to reconnect all disconnected connectors.
  4. Clear the CAN system related DTCs using the WDS or equivalent.
  5. Verify if the CAN system related DTCs are displayed using the WDS or equivalent. If the same following DTCs are present, replace the malfunctioning module. U0073 (PCM, TCM, DSC HU/CM, ABS HU/CM, keyless control module, instrument cluster) U2516 (steering angle sensor) If other DTC is present, perform the appropriate DTC inspection. (See «DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM]»(ref-244451-S40650496542006092400000) .)