NO.29 CONSTANT VOLTAGE [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)

29	Constant voltage
DESCRIPTION	• Incorrect constant voltage
POSSIBLE CAUSE	• Constant voltage circuit malfunction Note • The TP sensor, the EGR boost sensor and the FTP sensor use constant voltage.


STEP	INSPECTION		ACTION
1	• Disconnect the appropriate sensor connector when the constant voltage circuit inspection failed. • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between the following appropriate sensor connector terminals: - Constant voltage terminal and GND terminal • Is the constant voltage above 6.0 V?	Yes	Go to Step 13.
1		No	Go to the next step.
2	• Is the voltage across battery terminals above 10.5 V?	Yes	Go to the next step.
2	• Is the voltage across battery terminals above 10.5 V?	No	Inspect the charging system.
3	• Turn the ignition switch off. • Leave the appropriate sensor connector disconnected. • Measure the voltage between battery positive terminal and GND (between PCM and appropriate sensor) circuit at the appropriate sensor connector. • Is the voltage above 10.5 V and within 1.0 V of battery voltage?	Yes	Go to the next step.
3		No	Go to Step 8.
4	Note • The purpose of this step is to determine if the WDS or equivalent is communicating with the PCM. • Turn the ignition switch to the ON position (Engine off). • Attempt to access ECT PID. • Can ECT PID be accessed?	Yes	Go to Step 7.
4		No	Go to the next step.
5	• Turn the ignition switch off. • Disconnect the TP sensor, the EGR boost sensor and the PCM connectors. • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between PCM connector terminals 71/97 and 24/51/76/77/103. • Is the voltage above 10.5 V?	Yes	Go to the next step.
5		No	Repair open circuit between PCM terminal 71/97 and main relay.
6	• Leave the TP sensor, the EGR boost sensor, the FTP sensor and the PCM connectors disconnected. • Measure the resistance between PCM connector terminals 90 and 24/51/76/77/103. • Is the resistance above 10 kilohms?	Yes	Inspect for the constant voltage at the sensor connector again.
6		No	Repair the constant voltage circuit shorted to GND.
7	• Turn the ignition switch off. • Leave the TP sensor disconnected. • Disconnect the PCM connector. • Measure the resistance between PCM connector terminal 90 and the constant voltage circuit at the appropriate sensor connector. • Is the resistance below 5.0 ohms?	Yes	Inspect for the constant voltage at the sensor connector again.
7		No	Repair open the constant voltage circuit.
8	Note • The purpose of this step is to determine if the WDS or equivalent is communicating with the PCM. • Reconnect the TP sensor connector. • Turn the ignition switch on. • Attempt to access ECT PID. • Can ECT PID be accessed?	Yes	Go to the next step.
8		No	Go to Step 11.
9	• Are DTCs present for two or more sensors connected to PCM terminal 91? • Sensor connected to PCM terminal 91: - ECT sensor (P0117, P0118, P0125) - BARO sensor (P0107, P0108) (European (L.H.D.) specs.) - EGR boost sensor (P0106, P0107, P0108) (Australian, General (L.H.D. R.H.D.) specs.) - 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 the next step.
9		No	Repair open GND circuit to sensor where the constant voltage circuit inspection failed.
10	• Turn the ignition switch off. • Disconnect the WDS or equivalent from the DLC-2. • Disconnect the PCM connector. • Measure the resistance between GND circuit at appropriate sensor connector and PCM connector terminal 91. • Is the resistance below 5.0 ohms?	Yes	Reconnect the sensor connector. Go to the applicable DTC inspection. (See DTC TABLE [AJ] (VIN: JMZ LW19J7# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J*# 300001-301513).)
10		No	Repair open GND circuit.
11	• Turn the ignition switch off. • Disconnect the PCM connector. • Measure the resistance between battery negative terminal and PCM terminals 24/51/76/77/103. • Is each resistance below 5.0 ohms?	Yes	Go to the next step.
11		No	Repair open GND circuit.
12	• Turn the ignition switch off. • Measure the 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 the constant voltage at the sensor connector again.
12		No	Inspect for open GND circuit.
13	• Turn the ignition switch off. • Disconnect the TP sensor, the EGR boost sensor, the FTP sensor and the PCM connectors. • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between the constant voltage circuit at TP sensor connector and battery negative terminal. • Is the voltage below 0.5 V?	Yes	Inspect for the constant voltage at the sensor connector again.
13		No	Repair the constant voltage circuit shorted to power in the wiring 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 the PCM.