Many malfunctions in the electrical system are caused by poor harness(s) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Check the following conditions:
Check for damaged harness and terminals: contact resistance, oxidation, bent or broken terminals.
Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection
Use a suitable male pin to ensure that contact in sockets is good. The pin should remain in position when pulled gently.
Has a problem been found?
YES
Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
System OK. Go to "Verification of Vehicle Repair" procedure
After disconnecting CMPS connector,checking power line is for finding open circuit in CMPS wiring.
Turn ignition switch to OFF and disconnect CMPS connector.
Measure voltage of CKPS battery power circuit between CMPS harness connector and chassis ground.
Probe(+) : CMPS harness connector NO1.
Probe(-) : Chassis ground.
Specification: Approximately 12V
Is voltege within specification?
YES
Go to "OPEN CIRCUIT INSPECTION FOR SIGNAL LINE"
NO
Open or short circuit to chassis ground between CMPS harness connector and battery power circuit
Repair as necessary and go to "Verification of Vehicle Repair" procedure
1.In case,when CMPS connector is disconnected,the voltage at terminal 1 is 0V.
▶Possible cause : Open or short circuit between I/P-J/BOX fuse(15A) and CMPS terminal 1.
After disconnecting CMPS connector,the measurement of CMPS signal voltage is for finding open or short circuit by checking the pull-up voltage from ECM.
Turn ignition switch to OFF and disconnect CMPS connector.
Measure voltege of CMPS signal circuit between CMPS harnece connector and ECM harness connector.
Probe(+) : CMPS harness connector NO2.
Probe(-) : Chassis ground.
Specification: approximateiy 12V
Is each voltage within specification?
YES
Go to "OPEN CIRCUIT INSPECTION FOR GROUND LINE"
NO
Open or short circuit between CMPS harnece connector and ECM harness connector
Fault ECM
Repair as necessary and go to "Verification of Vehicle Repair" procedure
1.In case,when CMPS connector is disconnected,the voltage at terminal 2 is 0V.
▶Possible cause : Open signal line or faulty ECM
Turn ignition switch to OFF and disconnect CMPS connector.
Measure resistance or voltage of CMPS ground circuit between CMPS harness connector and chassis ground.
Probe(+) : CMPS harness connector NO3.
Probe(-) : Chassis ground.
Specification: below 1Ω ,below 0.5V
Is resistance or voltage within specification?
YES
Go to "SHORT CIRCUIT INSPECTION FOR SIGNAL LINE"
NO
Open circuit between CMPS harnece connector and Chassis ground
Repair as necessary and go to "Verification of Vehicle Repair" procedure
Turn ignition switch to OFF and disconnect CMPS connector and ECM connector.
Measure resistance of CMPS signal circuit between CMPS ground circuit and ECM harnece connector and Chassis ground.
Probe(+) : CMPS signal circuit harness connector NO2.
Probe(-) : CMPS ground circuit harness connector NO3.
Specification: infinite
Dose resistance indicate open circuit?
YES
Temporarily install a known good CMPS and check for proper operation
If problem is corrected, replace CMPS
ECM internal faulty
NO
Short circuit to chassis ground between CMPS harness connector and ECM harness connector
Short circuit between CMPS signal circuit and ground circuit
Repair as necessary and go to "Verification of Vehicle Repair" procedure
