Inspection Procedure O-14
Hood Switch Signal Is Not Sent to the ETACS-ECUHood Switch Input Circuit:
CIRCUIT OPERATION
The ETACS-ECU uses the input signal from the hood switch to arm the theft-alarm system.
TECHNICAL DESCRIPTION (COMMENT)
The hood switch input signal is used to arm the theft-alarm system. If the input signal is an error, the theft-alarm system will not be armed normally.
TROUBLESHOOTING HINTS
- Malfunction of the hood switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
STEP 1. Check the hood switch.
Q: Is the hood switch in good condition?
YES: Go to Step 2.
NO: Replace it. The input signal from the hood switch should be able to be checked and the theft-alarm system should be armed normally.
STEP 2. Check the hood switch ground circuit at hood switch connector A-23.
1. Disconnect hood switch connector A-23 and measure at the harness side.
2. Measure the resistance between terminal 2 and ground.
Q: Is the resistance less than 2 ohms?
YES: Go to Step 5.
NO: Go to Step 3.
STEP 3. Check hood switch connector A-23 for damage.
Q: Is hood switch connector A-23 in good condition?
YES: Go to Step 4.
NO: Repair or replace it. Refer to Harness Connector Inspection. The input signal from the hood switch should be able to be checked and the theft-alarm system should be armed normally
STEP 4. Check the harness wire between hood switch connector A-23 and ground.
Q: Is the harness wire between hood switch connector A-23 and ground in good condition?
YES: There is no action to be taken.
NO: Repair it. The input signal from the hood switch should be able to be checked and the theft-alarm system should be armed normally.
STEP 5. Check hood switch connector A-23 and ETACS-ECU connector C-112 for damage.
Q: Are hood switch connector A-23 and ETACS-ECU connector C-112 in good condition?
YES: Go to Step 6.
NO: Repair or replace them. Refer to Harness Connector Inspection. The input signal from the hood switch should be able to be checked and the theft-alarm system should be armed normally.
STEP 6. Check the harness wires between hood switch connector A-23 and ETACS-ECU connector C-112.
NOTE: After checking intermediate connector C-89, check the wires. If intermediate connector C-89 is damaged, repair or replace it. Refer to Harness Connector Inspection.
Q: Are the harness wires between hood switch connector A-23 and ETACS-ECU connector C-112 in good condition?
YES: Replace the ETACS-ECU. The input signal from the hood switch should be able to be checked and the theft-alarm system should be armed normally.
NO: Repair them. The input signal from the hood switch should be able to be checked and the theft-alarm system should be armed normally.