Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1580

TRANSMISSION CONTROL SYSTEM (4L30–E)

7A1–45

DTC P0719 Brake Switch Circuit Low (Stuck On) 

Step

Action

Yes

No

1

Was the Powertrain On–Board Diagnostic (OBD) System Check
performed?

Go to Step 2

Go to Powertrain

OBD System

Check

2

1. Install the scan tool.
2. With the engine “off,” turn the ignition switch to the “on”

position.

NOTE:  Before clearing the DTC(s), use the scan tool in order to
record the “Failure Records” for reference. Using the “Clear Info”
function will erase the stored “Failure Records” from the PCM.

3. Record the “DTC Failure Records”, then clear the DTC(s).
4. Select “TCC Brake Switch” on the scan tool.
5. Disconnect the brake switch connector from the brake switch.
6. Connect a test lamp from cavity I18–3 of the brake switch

connector to a known good ground.

Is the test lamp ON?

Go to Step 3

Go to Step 4

3

Install a J 36169–A Fused Jumper Wire from terminal I18–2 to
terminal I18–3 of the brake switch connector.

Did the TCC Brake Switch status change from Open to Closed?

Go to Step 7

Go to Step 9

4

1. Remove the fuse “ECM” (15A).
2. Inspect the fuse for an open.

Is the fuse open?

Go to Step 5

Go to Step 8

5

Inspect circuit WHT/GRN for a short to ground condition. Repair
the circuit if necessary.

Did you find a short to ground condition?

Go to Step 11

Go to Step 6

6

Inspect circuit GRY/RED–BRN/RED for a short to ground
condition. Repair the circuit if necessary.

Did you find a short to ground condition?

Go to Step 11

Go to Step 10

7

Replace the brake switch.

Is the replacement complete?

Go to Step 11

—

8

Inspect circuit WHT/GRN for an open condition. Repair the circuit
if necessary.

Did you find and correct an open condition?

Go to Step 11

—

9

Inspect circuit GRY/RED–BRN/RED for an open.

Did you find an open condition?

Go to Step 11

Go to Step 10

10

Replace the PCM.

Is the replacement complete?

Go to Step 11

—

11

In order to verify your repair, perform the following procedure:
1. Select DTC.
2. Select Clear Info.
3. With the engine “off,” turn the ignition switch to the “on”

position.

4. Do not depress the brake pedal.
5. Verify that the TCC Brake Switch status indicates “Closed” (12

volts) for 2 seconds.

6. Select Specific DTC. Enter DTC P0719.

Has the test run and passed?

System OK

Begin the

diagnosis again.

Go to Step 1

7A1–46 TRANSMISSION CONTROL SYSTEM (4L30–E)

DTC P0722 Automatic Transmission Output Speed Sensor (OSS) Low Input

D07RY00032

Circuit Description

Output speed information is provided to the PCM by the
OSS, which is a permanent magnet (PM) generator.  The
PM generator produces a pulsing AC voltage.  The AC
voltage level and number of pulses increases as the
speed of the vehicle increases.  The PCM then converts
the pulsing voltage to output speed, which is used for
calculations.  The vehicle speed can be displayed with a
scan tool.
This DTC detects a low output speed when there is a high
engine speed in a drive gear range.  This is a type “B”
DTC.

Conditions For Setting The DTC

D

No MAP DTCs P0107 or P0108, P0106, P1106,
P1107.

D

No TPS DTCs P0122 or P0123.

D

Not in Park or Neutral.

D

TP angle is greater than 10%.

D

Engine vacuum is between 0 and 70kPa.

D

Engine speed is between 3000 and 7000 rpm.

D

Transmission output speed is less than 0 rpm.

D

All conditions met for 5 seconds.

Action Taken When The DTC Sets

D

Fixed to 4th gear.

D

Maximum line pressure.

D

Inhibit TCC engagement.

D

For lamp illuminate refer to DTC type definition (type
B).

Conditions For Clearing The MIL/DTC

D

The PCM will turn off the MIL and CHECK TRANS
Lamp after three consecutive ignition cycles without a
failure reported.

D

The DTC can be cleared from the PCM history by
using a scan tool.  The DTC will be cleared from
history when the vehicle has achieved 40 warmup
cycles without a failure reported.

D

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled “off”
long enough to power down the PCM.

Diagnostic Aids

D

An OSS DTC P0722 will set when no output speed is
at detected at start off.

D

Inspect the wiring for poor electrical connection at the
PCM.  Look for possible bent, backed out, deformed
or damaged terminals.  Check for weak terminal
tension as well.  Also check for a chafed wire that
could short to bare metal or other wiring.  Inspect for a
broken wire inside the insulation.

D

When diagnosing for a possible intermittent short or
open condition, move or massage the wiring harness
while observing test equipment for a change.

Test Description

The numbers below refer to the step numbers on the
diagnostic chart:
4. This test checks the OSS circuit.
5. This test checks the integrity of the OSS.
7. This test checks the 5–volt and ground circuit of the

PCM.

TRANSMISSION CONTROL SYSTEM (4L30–E)

7A1–47

DTC P0722 Automatic Transmission Output Speed Sensor (OSS) Low Input 

Step

Action

Yes

No

1

Were you sent here from the “Powertrain On–Board Diagnostic
(OBD) System Check”?

Go to Step 2

Go to OBD

System Check

Refer to

Driveability and

Emissions in

Engine section

2

1. Install the scan tool.
2. With the engine “off”, turn the ignition switch “on”.

NOTE: Before clearing DTC(s), use the scan tool to record “Freeze
Frame” and “Failure Records” for reference, as data will be lost
when the “Clear Info” function is used.

3. Record the DTC “Freeze Frame” and “Failure Records”.
4. Raise the drive wheels.
5. Start the engine.
6. Place the transmission in any drive range.

With the drive wheels rotating, does the “Trans Output Speed”
increase with the drive wheel speed?

Go to Diagnostic

Aids

Go to Step 3

3

Check for the most current and/or incorrect calibration.

Is the calibration current?

Go to Step 16

Go to Step 4

4

1. Turn the ignition “off”.
2. Disconnect the J2 (RED) PCM connector.
3. Using the J39200 DVOM, measure the resistance between

harness connector terminals J2–22 and J2–55.

Is the reading 3000 ohms?

Go to Step 5

Go to Step 6

5

1. Select AC volts.
2. Rotate the rear wheels, ensuring the driveshaft is turning.

Is the voltage greater than 0.5 volts?

Go to Step 7

Go to Step 8

6

Inspect circuits BLU/YEL and BLU/GRN for a poor connection or
an open circuit.

Was a problem found?

Go to Step 17

Go to Step 8

7

1. Reconnect the J2 (RED) PCM connector.
2. Disconnect the OSS harness from the OSS.
3. With the engine “off”, turn the ignition “on”.
4. Using the J 39200 DVOM, measure the voltage at the OSS

harness connector terminals E55–1 and E55–2.

Is the reading between 4.0 to 5.1 volts?

Go to Step 16

Go to Step 10

8

1. Remove the OSS.
2. Check the output shaft speed sensor rotor for damage or

misalignment. Refer to Speed Sensor (Extension Housing) in
Automatic Transmission (4L30–E) section.

Was a problem found?

Go to Step 17

Go to Step 9

9

Replace the OSS.

Is the replacement complete?

Go to Step 17

—

10

Was the reading in step 7 less than 4.0 volts?

Go to Step 12

Go to Step 11

11

Was the reading in Step 7 greater than 5.1 volts?

Go to Step 15

—

12

Using the J 39200 DVOM to chassis ground, measure the voltage
on circuit BLU/YEL.

Is the reading between 4.0 to 5.1 volts?

Go to Step 13

Go to Step 14

7A1–48 TRANSMISSION CONTROL SYSTEM (4L30–E)

DTC P0722 Automatic Transmission Output Speed Sensor (OSS) Low Input  (Cont’d)

Step

No

Yes

Action

13

Repair the open in circuit BLU/GRN.

Is the repair complete?

Go to Step 17

—

14

Check circuit BLU/YEL for a short to ground or open.

Was a problem found and corrected?

Go to Step 17

Go to Step 16

15

Repair the short to B+ in circuit BLU/YEL.

Is the repair complete?

Go to Step 17

—

16

Replace the PCM. Refer to Powertrain Control Module (PCM) in
automatic Transmission (4L30–E) section.

Is the replacement complete?

Go to Step 17

—

17

1. After the repair is complete, use the scan tool to select “DTC”,

then “Clear Info” function and operate the vehicle under the
following conditions:
Transmission output speed is greater than 101 rpm for 3
seconds.

2. Review the scan tool “DTC Info”.

Has the last test failed or is the current DTC displayed?

Begin diagnosis

again

Go to Step 1

Repair verified
Exit DTC table