DTC 5-3-2
5-3-2 POWER STAGE GROUP BPreconditions for DTCs
^ If the ECM registers a fault in one of the circuits for the Idle Air Control (IAC) valve, Fan Control (FC) relay or Turbocharger (TC) control valve but cannot determine which circuit is faulty, DTC 5-3-2 is set.
Substitute value
^ Idle air trim inhibited.
^ Fuel trim inhibited.
^ Conditions for fuel shut-off altered.
Fault sources
^ Break in IAC valve's voltage lead:
^ Break, short circuiting to ground or short circuiting to voltage supply in the IAC valve's signal leads.
^ Short circuiting of IAC valve's signal leads to each other.
^ Break in FC relay's voltage lead.
^ Break, short circuiting to ground or short circuiting to voltage supply in FC relay's signal leads.
^ Break in TC control valve's voltage lead.
^ Break, short circuiting to ground or short circuiting to voltage supply in TC control valve's signal lead.
^ Loose connection in the IAC valve's, TC control valve or FC relays connector.
Fault symptoms
^ Uneven idling, depending on fault source.
^ Engine jerks under load, depending on fault source.
^ Disruption in engine cooling fan half speed.
TESTING PROCEDURE
Other DTCs
^ Read off other DTCs.
If DTC 2-2-3 is stored:
- See: Testing By Trouble Code / DTC 2-2-3 Idle Air Control Valve Opening Signal.
If DTC 2-4-5 is stored:
- See: Testing By Trouble Code / DTC 2-4-5 Idle Air Control Valve Closing Signal.
If DTC 5-1-4 is stored:
- See: Testing By Trouble Code / DTC 5-1-4 Engine Cooling Fan Low Speed Signal.
If DTC 5-3-5 is stored:
- See: Testing By Trouble Code / DTC 5-3-5 Turbocharger Control Valve Signal.
If none of the above DTCs are stored:
- Check the IAC valve.
Checking the IAC Valve
^ Disconnect three injectors, refit after completing the test.
^ Use Diagnostic Test Mode (DTM) 3 to verify that the IAC valve works.
If the IAC valve functions:
- Check the engine cooling fan.
If the IAC valve does not function:
- Check the voltage supply to the IAC valve.
Checking the Voltage to the IAC Valve
^ Switch Ignition OFF.
^ Disconnect the IAC valve.
^ Switch Ignition ON.
^ Connect a voltmeter between IAC valve connector 2 and ground.
The voltmeter should show battery voltage.
If the reading is OK:
- Check the IAC valve.
If the reading is incorrect:
- Check the lead between IAC valve connector 2 and main relay (2/32) connector 3 for signs of a break.
Checking the IAC Valve
^ Switch Ignition OFF.
^ IAC valve disconnected.
^ Connect an ohmmeter between connector 1 and 2 on the IAC valve.
^ Read the value.
^ Then connect the ohmmeter between connector 2 and 3 at the IAC valve.
^ Read the value.
The ohmmeter should show 9 - 14 ohms at +20°C (68°F), in both cases.
If the values are OK:
- Check the signal lead (opening).
If the readings are incorrect:
- Test with a new IAC valve.
Checking the Signal Lead (opening)
^ Switch Ignition ON.
^ IAC valve disconnected.
^ Connect a voltmeter between IAC valve connector 3 and ground.
The voltmeter should show approx. 0 Volts.
If the reading is OK:
- Check the signal lead (opening) resistance to ground.
If the reading is incorrect:
- Check the lead between IAC valve connector 3 and ECM A11 for signs of short circuiting to voltage supply.
Checking the Signal Lead (opening) Resistance to Ground
^ Switch Ignition OFF.
^ Wait for 150 seconds.
^ IAC valve disconnected.
^ Connect an ohmmeter between IAC valve connector 3 and ground.
The ohmmeter should show 10 - 20K ohms.
If the reading is OK:
- Check the signal lead (closing).
If the ohmmeter shows infinite resistance:
- Check the ECM connector.
If the ohmmeter shows approx. 0 ohms:
- Check the lead between IAC valve connector 3 and ECM All for signs of short circuiting to ground.
Checking the ECM Connector
^ Switch Ignition OFF.
^ IAC valve disconnected.
^ Rectify the ECM connector with regard to contact resistance and oxidation.
^ ECM connected.
^ Connect an ohmmeter between IAC valve connector 3 and ground.
The ohmmeter should show 10 - 20K ohms.
If the reading is OK:
- The source of the DTC is poor contact in the ECM connector.
If the reading is incorrect:
- Check the lead between IAC valve connector 3 and ECM A11 for signs of a break.
Checking the Signal Lead (closing)
^ Switch Ignition ON.
^ IAC valve disconnected.
^ Connect a voltmeter between IAC valve connector 1 and ground.
The voltmeter should show approx. 0 Volts.
If the reading is OK:
- Check the signal lead (closing) resistance to ground.
If the reading is incorrect:
- Check the lead between IAC valve connector 1 and ECM A25 for signs of short circuiting to voltage supply.
Checking the Signal Lead (closing) Resistance to Ground
^ Switch Ignition OFF.
^ Wait for about 150 seconds.
^ IAC valve disconnected.
^ Connect an ohmmeter between IAC valve connector 1 and ground.
The ohmmeter should show 10 - 20K ohms.
If the reading is OK:
- The source of the DTC is poor contact in the IAC valve's connector.
- Rectify the connector with regard to a loose connection as well as contact resistance and oxidation.
If the ohmmeter shows infinite resistance:
- Check the ECM connector.
If the ohmmeter shows approx. 0 ohms:
- Check the lead between IAC valve connector 1 and ECM A25 for signs of short circuiting to ground.
Checking the ECM Connector
^ Switch Ignition OFF.
^ IAC valve disconnected.
^ Rectify the ECM connector for signs of contact resistance and oxidation.
^ ECM connected.
^ Connect an ohmmeter between IAC valve connector 1 and ground.
The ohmmeter should show 10 - 20K ohms.
If the reading is OK:
- The source of the DTC is poor contact in the ECM connector.
If the reading is incorrect:
- Check the lead between IAC valve connector 1 and ECM A25 for signs of a break.
Checking the Engine Cooling Fan
^ Use DTM 3 to verify that the engine cooling fan functions.
If the engine cooling fan functions:
- Check the turbo control (TC) valve.
If the engine cooling fan does not function:
- Check the voltage to the FC relay.
Checking the Voltage to the Fan Control (FC) Relay
^ Switch Ignition OFF.
^ Disconnect connector A from the fan control (FC) relay.
^ Switch Ignition ON.
^ Connect a voltmeter between FC relay connector A (for ECM) and ground.
The voltmeter should show battery voltage.
If the reading is OK:
- Check the FC relay.
If the reading is incorrect:
- The lead between the starter motor and FC relay has an integrated fusible link. If there is a break in this lead, the probable cause is short circuiting to ground in the circuit. Check the FC relay and fan motor before replacing the lead. Check the lead between the starter motor and FC relay connector A1 for signs of a break.
Checking the FC Relay
^ Switch Ignition OFF.
^ Disconnect connector B from the FC relay.
^ Connector A disconnected.
^ Connect an ohmmeter between connector A1 and B1 on the FC relay.
The ohmmeter should show approx. 80 ohms at +20°C (68°F).
If the reading is OK:
- Check the signal lead, half speed.
If the reading is incorrect:
- Test with a new FC relay.
Checking the Signal Lead, Half Speed
^ Switch Ignition ON.
^ Connector B disconnected.
^ Connect a voltmeter between FC relay connector B, connector 1 (to ECM) and ground.
The voltmeter should show approx. 0 Volts.
If the reading is OK:
- Check the signal lead (half speed) resistance to ground.
If the reading is incorrect:
- Check the lead between FC relay connector B1 and ECM A7 for signs of short circuiting to voltage supply.
Checking the Signal Lead (half speed) Resistance to Ground
^ Switch Ignition OFF.
^ Wait for about 150 seconds.
^ Connector B disconnected.
^ Connect an ohmmeter between FC relay connector B, connector 1 (to ECM) and ground.
The ohmmeter should show 28 - 38K ohms.
If the reading is OK:
- Check the signal lead (full speed) resistance to ground.
If the ohmmeter shows infinite resistance:
- Check the ECM connector.
If the ohmmeter shows approx. 0 ohms:
- Check the lead between FC relay connector B1 and ECM A7 for signs of short circuiting to ground.
Checking the ECM Connector
^ Switch Ignition OFF.
^ Connector B disconnected.
^ Rectify the ECM connector with regard to contact resistance and oxidation.
^ ECM connected.
^ Connect an ohmmeter between FC relay connector B, connector 1 (to ECM) and ground.
The ohmmeter should show 28 - 38K ohms.
If the reading is OK:
- The source of the DTC is poor contact in the ECM connector.
If the reading is incorrect:
- Check the lead between FC relay connector B1 and ECM A7 for signs of a break.
Checking the Signal Lead (full speed) Resistance to Ground
^ Switch Ignition OFF.
^ Connector B disconnected.
^ Connect an ohmmeter between FC relay connector B, connector 2 (to ECM) and ground.
The ohmmeter should show 100K ohms - infinite resistance.
If the reading is OK:
- The source of the DTC is poor contact in the FC relay connector.
- Rectify the connectors with regard to loose connection, contact resistance and oxidation.
If the ohmmeter shows approx. 0 ohms:
- Check the lead between FC relay connector B2 and ECM A22 for signs of short circuiting to ground.
Checking the Turbocharger (TC) Control Valve
^ Use DTM 3 to verify that the TC control valve is functioning.
If the TC control valve functions:
- The fault is intermittent, proceed to: INTERMITTENT FAULT section below.
If the TC control valve does not function:
- Check the voltage to TC control valve.
Checking the Voltage to the TC Control Valve
^ Switch Ignition OFF.
^ Disconnect the TC control valve.
^ Switch Ignition ON.
^ Connect a voltmeter between TC control valve connector 1 and ground.
The voltmeter should show battery voltage.
If the reading is OK:
- Check the TC control valve.
If the reading is incorrect:
- Check the lead between TC control valve connector 1 and main relay (2/32) connector 3 for signs of a break.
Checking the TC Control Valve
^ Switch Ignition OFF.
^ TC control valve disconnected.
^ Connect an ohmmeter between connector 1 and 2 on the TC control valve.
The ohmmeter should show 22 - 26 ohms at +20°C (68°F).
If the reading is OK:
- Check the signal lead.
If the reading is incorrect:
- Test with a new TC control valve.
Checking the Signal Lead
^ Switch Ignition ON.
^ TC control valve disconnected.
^ Connect a voltmeter between TC control valve connector 2 and ground.
The voltmeter should show approx. 0 Volts.
If the reading is OK:
- Check the signal lead resistance to ground.
If the reading is incorrect:
- Check the lead between TC control valve connector 2 and ECM B41 for signs of short circuiting to voltage supply.
Checking the Signal Lead Resistance to Ground
^ Switch Ignition OFF.
^ Wait for about 150 seconds.
^ IAC valve disconnected.
^ Connect an ohmmeter between TC control valve connector 2 and ground.
The ohmmeter should show 27 - 37K ohms.
If the reading is OK:
- The source of the DTC is poor contact in the TC control valve connector.
- Rectify the connector with regard to a loose connection, contact resistance and oxidation.
If the ohmmeter shows infinite resistance:
- Check the ECM connector.
If the ohmmeter shows approx. 0 ohms:
- Check the lead between TC control valve connector 2 and ECM B41 for signs of short circuiting to ground.
Checking the ECM Connector
^ Switch Ignition OFF.
^ TC control valve disconnected.
^ Rectify the ECM connector with regard to contact resi stance and oxidation.
^ ECM connected.
^ Connect an ohmmeter between TC control valve connector 2 and ground.
The ohmmeter should show 27 - 37K ohms.
If the reading is OK:
- The source of the DTC is poor contact in the ECM connector.
If the reading is incorrect:
- Check the lead between TC control valve connector 2 and ECM B41 for signs of a break.
INTERMITTENT FAULT
Checking the Leads and Connectors
^ Check the lead between main relay (2/32) connector 3 and IAC valve connector 2 for signs of an intermittent break.
^ Check the lead between IAC valve connector 1 and ECM A25 for signs of an intermittent break, intermittent short circuiting to ground as well as intermittent short circuiting to voltage supply.
^ Check the lead between IAC valve connector 3 and ECM A11 for signs of an intermittent break, intermittent short circuiting to ground as well as intermittent short circuiting to voltage supply.
^ Check the lead between IAC valve connector 1 and ECM A25 for signs of short circuiting to the lead between IAC valve connector 3 and ECM A11.
^ Check the lead between FC relay connector A1 and battery positive terminal for signs of an intermittent break.
^ Check the lead between FC relay connector B1 and ECM A7 for signs of an intermittent break, intermittent short circuiting to ground as well as intermittent short circuiting to voltage supply.
^ Check the lead between TC control valve connector 1 and battery positive terminal for signs of an intermittent break.
^ Check the lead between TC control valve connector 2 and ECM B41 for signs of an intermittent break, intermittent short circuiting to ground as well as intermittent short circuiting to voltage supply.
^ Check the main relay's, IAC valve's, FC relay's, TC control valve's and ECM's connectors for signs of a loose connection.