Opel Frontera UE. Manual - part 965

6E2–246

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

intake manifold, leaks at the throttle body, faulty or
incorrectly installed PCV valve, leaks at the intake
manifold, etc.

Throttle body – Check for sticking throttle plate. Also
inspect the IAC passage for deposits or objects which
keep the IAC pintle from fully extending.

Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.

DTC P1509 –IAC System High RPM

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Start the engine.
2. Turn all accessories “OFF” (A/C, rear defroster,

etc.).

3. Using a Tech 2, command RPM up to 1500, down to

500, and then up to 1500 while monitoring “Engine
Speed” on the Tech 2.

NOTE: This Tech 2 command may cause the engine to
“cut out” when RPM goes above 1500. If this occurs,
the “cutting out” will stop when the Tech 2 command for
the test is discontinued, or if the Tech 2 command is
changed to less than 1500 RPM.

Does the “Engine Speed” remain within the specified
value of “Desired Idle” for each RPM command?

50 RPM

No trouble

found. Go to

Diagnostic

Aids

Go to

Step 3

1. Disconnect the IAC.
2. Install IAC Noid Light 5–8840–2312–0 or

equivalent.

3. With the engine running, command RPM up to

1500, down to 500, and then up to 1500 while
observing the noid light.

Does each noid light cycle red and green (never
“OFF”)?

—

Go to

Step 5

Go to

Step 4

1. Check the following circuits for an open, short to

voltage, short ground, or poor connections at the
PCM:

IAC “A” Low.

IAC “A” High.

IAC “B” Low.

IAC “B” High.

2. If a problem its found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 8

6E2–247

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P1509 –IAC System High RPM

(Cont'd)

Step

Yes

Value(s)

Action

Visually/physically inspect for the following conditions:

Vacuum leaks.

Throttle plate or throttle shaft for binding.

Accelerator and cruise control cables for being
misadjusted or for binding.

Faulty, missing, or incorrectly installed PCV
valve.

Do any of the above require a repair?

—

Refer to

appropriate

section for

on-vehicle

service

Go to

Step 6

1. Check for a poor connection at the IAC harness

connector.

2. If a problem is found, replace faulty terminals as

necessary.

Was a problem found?

—

Verify repair

Go to

Step 7

Replace the IAC valve.

Is the action complete?

—

Verify repair

—

Replace the PCM.

Is the action complete?

—

Verify repair

—

6E2–248

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1625 PCM Unexpected Reset

Circuit Description

The powertrain control module (PCM) monitors
unexpected PCM reset. This will not turn on MIL light on,
only records code DTC P1625.

Conditions for Setting the DTC

Clock or COP (Computer Operating Properly) reset.

Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P1625 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1625 can be cleared by disconnecting the PCM
battery feed.

Diagnostic Aids

Check for the following conditions:

P1625 alone stored does not need diagnosis. Clear
DTC code.

DTC P1625 – PCM Unexpected Reset

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to

OBD

System

Check

1. Ignition is “ON”.
2. Install the Tech 2.
3. Start the engine at let it Idle.
4. On the Tech 2, select “DTC info”.

Does the Tech 2 indicate DTC P1625 failed?

—

Go to

Step 3

Go to

Diagnostic

Aids

1. Ignition is “ON”.
2. Clear DTC P1625 by using the Tech 2 “Clear Info”.
3. Start the engine at let it Idle.
4. On the Tech 2, select “DTC info”.

Does the Tech 2 indicate DTC P1625 failed?

—

Go to

Step 4

Go to

Diagnostic

Aids

1. Check for aftermarket electronics, such as

transceiver, stereos, and anti theft devices. May
radiate EMI into the control system if they are
improperly installed. (This may cause a false sensor
reading and turn on the MIL.)

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

—

6E2–249

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC)

P1640 Output Driver Module (ODM) “A” Fault

Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

A history DTC P1640 will clear after 40 consecutive
warm-up cycles occur without a fault.

DTC P1650 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

Check for the following conditions:

Poor connection at PCM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness – Inspect the wiring harness for
damage, If the harness appears to be OK, disconnect
the PCM, turn the ignition “ON” and observe a
voltmeter connected to the suspect driver circuit at the
PCM harness connector while moving connectors and
wiring harnesses relates to the MIL. A change in
voltage will indicate the location of the fault.

Poor connection at component – Examine for
damaged connectors, unplugged connector, or

damaged terminals at the following locations: canister
purge solenoid, Fuel level check.

The following PCM pins are controlled by
output driver modules (ODMs):

A13 – MIL (Check Engine)

A14 – Check T/M or Up-Shift

A15 – EVAP Canister Purge

A16 – Band Apply (4L30E)

B14 – A/C Clutch

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
4. The Tech 2 Driver Module Status indicates the PCM

pin that is affected.

9. The Tech 2 may indicate “short circuit” even when

the problem is an open circuit. The cause of an
open circuit may be in the component itself.

11.A short to ground on the ignition side of the

component will blow the fuse. Since the fuse was
checked in Step 2, a short to ground would be
between the affected component and the PCM.

DTC P1640 –Output Driver Module (ODM) “A” Fault

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

Check the fuse for the driver circuit that was shown as
faulty.

Was the fuse blown?

—

Go to

Step 3

Go to

Step 4

1. Check for a short to ground between the fuse and

the affected component.

2. Replace the fuse after making any necessary

repairs.

Is the action complete?

—

Verify repair

—

1. Disconnect the PCM connector for the affected
driver circuit.

Is there any damage to the PCM pin or connector?

—

Go to

Step 5

Go to

Step 6

Repair the damaged pin or terminal.

Is the action complete?

—

Verify repair

—

Were either of the lamp circuits for “Check Engine” or
“Check Trans.” indicated as faulty by the Tech 2?

—

Go to

Step 7

Go to

Step 13

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