NO.29 CONSTANT VOLTAGE [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))


BME010300000W16

29

Constant voltage

DESCRIPTION

• Incorrect constant voltage

POSSIBLE CAUSE

• Constant voltage circuit malfunction
Note
• TP sensor, EGR boost sensor and FTP sensor use constant voltage.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
• Disconnect appropriate sensor connector when constant voltage circuit inspection failed.
• Turn ignition switch to ON (Engine OFF).
• Measure voltage between following appropriate sensor connector terminals:
- Constant voltage terminal and GND terminal
• Is constant voltage above 6.0 V?
Yes
Go to Step 13.
No
Go to next step.
2
• Is voltage across battery terminals above 10.5 V?
Yes
Go to next step.
No
Inspect charging system.
3
• Turn ignition switch to OFF.
• Leave appropriate sensor connector disconnected.
• Measure voltage between battery positive terminal and GND (between PCM and appropriate sensor) circuit at appropriate sensor connector.
• Is voltage above 10.5 V and within 1.0 V of battery voltage?
Yes
Go to next step.
No
Go to Step 8.
4
Note
• Purpose of this step is to determine if WDS or equivalent is communicating with PCM.
• Turn ignition switch to ON (Engine OFF).
• Attempt to access ECT PID.
• Can ECT PID be accessed?
Yes
Go to Step 7.
No
Go to next step.
5
• Turn ignition switch to OFF.
• Disconnect TP sensor, EGR boost sensor and PCM connectors.
• Turn ignition switch to ON (Engine OFF).
• Measure voltage between PCM connector terminals 34/60 and 6/22/23/25/100.
• Is voltage above 10.5 V?
Yes
Go to next step.
No
Repair open circuit between PCM terminal 71/97 and main relay.
6
• Leave TP sensor, EGR boost sensor, FTP sensor and PCM connectors disconnected.
• Measure resistance between PCM connector terminals 33 and 6/22/23/25/100.
• Is resistance above 10 kilohms?
Yes
Inspect for constant voltage at suspect sensor connector again.
No
Repair constant voltage circuit shorted to GND.
7
• Turn ignition switch off.
• Leave TP sensor disconnected.
• Disconnect PCM connector.
• Measure resistance between PCM connector terminal 33 and constant voltage circuit at appropriate sensor connector.
• Is resistance below 5.0 ohms?
Yes
Inspect for constant voltage at suspect sensor connector again.
No
Repair open constant voltage circuit.
8
Note
• Purpose of this step is to determine if WDS or equivalent is communicating with PCM.
• Reconnect TP sensor connector.
• Turn ignition switch on.
• Attempt to access ECT PID.
• Can ECT PID be accessed?
Yes
Go to next step.
No
Go to Step 11.
9
• Are DTCs present for two or more sensors connected to PCM terminal 20?
• Sensor connected to PCM terminal 20:
- ECT sensor (P0117, P0118, P0125)
- BARO sensor (P2227, P2228.P2229) or (P2228,P2229)
- HO2S (front) (P0131, P0132, P0134, P0151, P0152, P0154)
- HO2S (rear) (P0138, P0140, P0158, P0160)
- IAT sensor (P0111, P0112, P0113)
- TP sensor (P0121, P0122, P0123)
Yes
Go to next step.
No
Repair open GND circuit to sensor where constant voltage circuit inspection failed.
10
• Turn ignition switch to OFF.
• Disconnect WDS or equivalent from DLC-2.
• Disconnect PCM connector.
• Measure resistance between GND circuit at appropriate sensor connector and PCM connector terminal 20.
• Is resistance below 5.0 ohms?
Yes
Reconnect sensor connector.
Go to appropriate DTC test.
No
Repair open GND circuit.
11
• Turn ignition switch to OFF.
• Disconnect PCM connector.
• Measure resistance between battery negative terminal and PCM terminals 6/22/23/25/100.
• Is each resistance below 5.0 ohms?
Yes
Go to next step.
No
Repair open GND circuit.
12
• Turn ignition switch to OFF.
• Measure resistance between GND circuit at following sensor connector and GND:
- TP sensor
- EGR boost sensor
- ECT sensor
- IAT sensor
- HO2S (front)
- HO2S (rear)
• Is each resistance below 5.0 ohms?
Yes
GND circuits are normal.
Inspect for constant voltage at suspect sensor connector again.
No
Inspect for open GND circuit.
13
• Turn ignition switch to OFF.
• Disconnect TP sensor, EGR boost sensor, FTP sensor and PCM connectors.
• Turn ignition switch to ON (Engine OFF).
• Measure voltage between constant voltage circuit at TP sensor connector and battery negative terminal.
• Is voltage below 0.5 V?
Yes
Inspect for constant voltage at suspect sensor connector again.
No
Repair constant voltage circuit shorted to power in harness.
14
• Verify test results.
- If normal, return to diagnostic index to service any additional symptoms.
- If malfunction remains, inspect related Service Information and perform repair or diagnosis.
• If vehicle is repaired, troubleshooting completed.
• If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram PCM.