1A-196 Engine Control System (4HK1)
Circuit/ System Testing DTC P0478
14
Observe the DTC Information with a scan tool.
Are there any DTCs that you have not
diagnosed?
—
Go to DTC List System OK
Step Action Value(s) Yes No
Step Action Value(s) Yes No
1
Did you perform the Diagnostic System Check
- Engine Controls?
—
Go to Step 2
Go to Diagnostic
System Check -
Engine Controls
2
1. Install a scan tool.
2. Perform the Exhaust Brake Control with a
scan tool.
3. Command the solenoid valve ON and OFF.
Does the solenoid valve click with each
command?
—
Go to Diagnostic
Aids Go to Step 3
3
1. Turn OFF the ignition.
2. Disconnect the exhaust brake control solenoid
valve harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Monitor the DTC Information with a scan tool.
Is DTC P0477 set, but not P0478?
—
Go to Step 5 Go to Step 4
4
1. Test the control circuit between the ECM (pin
15 of J-14) and the solenoid valve (pin 2 of J-
26) for a short to battery or ignition voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
—
Go to Step 7 Go to Step 6
5
Replace the exhaust brake control solenoid valve.
Did you complete the replacement?
—
Go to Step 7
—
6
Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
—
Go to Step 7
—
7
1. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Perform the Exhaust Brake Control with a
scan tool.
5. Command the solenoid valve ON and OFF.
Does the solenoid valve click with each
command?
—
Go to Step 8 Go to Step 3
8
Observe the DTC Information with a scan tool.
Are there any DTCs that you have not
diagnosed?
—
Go to DTC List System OK
LG4HKED-WE-0871.book 196 ページ 2007年11月29日 木曜日 午後6時29分