Ignition - Auto Diagnostic/Detonation LED Flashing
89Peugeot07BULLETIN NO. 365 ( 1)
DATE: October, 1989 89
SUBJECT: IGNITION AUTODIAGNOSTIC/DETONATION LED FLASHING
MODELS: 505 V6 ENGINE VEHICLES
COMPLAINT:
Yellow LED in instrument cluster emits constant flashes
INFORMATION:
The EZ115K ignition ECU incorporates an "auto-diagnostic" feature which enables it to identify eventual malfunctions which could occur during operation.
These malfunctions are brought to the driver's attention by a yellow LED on the instrument cluster.
The number of flashes (codes) usually identifies the specific component which is malfunctioning.
NOTE: An occasional blink of the LED indicates detonation sensing and correction, which is totally normal under certain driving conditions, depending on the quality of fuel being used.
Number of Flashes Components Involved
Series of 2 NTC Temperature Sensor
Series of 4 Detonation Sensor or Ignition ECU
Series of 5 Erroneous Load Signal from Injection ECU
Series of 6 Number 1 Cylinder Sensor
Constant series of flashes of the LED usually associated with either a fouror six-flash code are in most cases due to intermittent poor electrical contact in the wiring terminals connecting the components indicated above.
Once the ignition ECU has detected an intermittent electrical problem, the LED will remain in the constant flashing mode until the engine is turned off. Once the engine is restarted, the ECU will have cleared its memory of the intermittent wiring problem.
The following procedure should be followed prior to attempting to replace any components, which in most cases are not the cause of the problem.
REPAIR PROCEDURE:
I - Locate wiring connectors MC26 and MC27 at cowl panel on right side of brake fluid reservoir:
MC26 is a 9-pin blue connector with wires:
19/19A at pin 1
18/18A at pin 2 - No. 1 Cylinder Position Sensor Wiring
M19A/M21 at pin 3
10 at pin 4
23 at pin 5 - Engine RPM Sensor
M11 at pin 6
M24/M24B at pin 7
24/24B at pin 8 - Right Bank Detonation Sensor
25/25A at pin 9
MC27 is a 4-pin blue connector with wires:
M12/M12C at pin 1
12/12C at pin 2 - Left Bank Detonation Sensor
13/13A at pin 3
M2 at pin 4 - Ground for Ignition ECU/Amplifier Module
ECU Relay
- Disconnect both connectors and check that each individual terminal is fully locked into connector housing.
- Apply electrical or "tuner" spray contact cleaner to both connector terminals.
- Apply a dab of electrical contact/anti-corrosion grease, "Dow Corning 4 Compound" or equivalent, to each individual wire terminal.
- Fully reconnect both connectors.
- Using a small flat-bladed screwdriver, from the back of the connector, push in each individual terminal all the way into the connector housing while holding the opposite wire; reverse the procedure on opposite side of both connectors.
- Make sure that there is sufficient slack in the wiring to prevent pulling on the wire terminals.
II - Locate and disconnect both detonation sensors (connectors located on top of "V" in center of both cylinder heads).
- Locate and disconnect the No. 1 cylinder sensor (connector located on right side of power steering reservoir).
- Apply electrical or "tuner" spray contact cleaner to both connector terminals.
- Apply a dab of electrical contact grease on each individual terminal and fully reconnect the three connectors.
- ROAD TEST VEHICLE
ONLY IF CONDITION PERSISTS AFTER HAVING PERFORMED PROCEDURES I AND II:
Basic Checks to be Performed:
- Check the main engine ground for tightness and continuity; the main engine ground is located under the distributor head on the side of the cylinder block.
- Check the tightness and continuity of the battery post and terminals.
- Check the rotor arm and distributor cap for cracking, burning and erosion.
- Check the condition of the air filter element and the associated ducting for any blockages or a clogged filter element.
- Check the electrical operation of the throttle switch at the two electronic control unit plug-in connectors. Disconnect the ignition ECU:
Connect a multimeter (Ohms scale) between terminals 3 and 25 of injection ECU; the reading should be:
Pedal at rest - Less than 1 ohm
Pedal depressed - Infinity
Connect a multimeter (Ohms scale) between terminals 12 and
25 of injection ECU; the reading should be:
Pedal at rest - Infinity
Pedal depressed - Less than 1 ohm
Connect a multimeter (Ohms scale) between terminal 3 on the throttle switch harness and terminal 7 on the ignition ECU and check the continuity.
If any of the readings are incorrect, check the throttle switch adjustment (page F2016 of Workshop Manual) and then check the connectors and wiring harnesses. If no fault is found, replace the throttle switch and recheck.
- Ensure that the air flow sensor is undergoing "pyrolysis." To check this, run the engine up to normal running temperature (above 65~C) and above 1500 rpm. Disconnect the air filter from the end of the sensor and turn off the engine. After a 5-second period, the platinum hot wire should glow for 1 second. If this does not occur, check that wires nos. 6 and 8 are in the correct pins.
Wire No. 6 - Pin 2 of Air Flow Sensor Connector to Pin 6 of Injection ECU
Wire No. 8 - Pin 4 of Air Flow Sensor Connector to Pin 8 of Injection ECU
- Check/adjust throttle flap initial position (page F2012 of 505 V6 Workshop Manual).
- Check/adjust idle speed preset (page F2012).
- Check/adjust fuel mixture at idle (page F2015) to obtain an alternate sweep from 0 to 13 volts and from 13 to 0 volts at test wire no. 22.
Four Flash Code:
If a detonation sensor is suspected to be malfunctioning after having performed the electrical check indicated on page G2010 of the 505 V6 Workshop Manual, it is possible for troubleshooting purposes to road test the vehicle with a new detonation sensor (P/N 5946.05) temporarily mounted to the cylinder head:
- Remove the left side engine lifting hook and bolt a new sensor in its place.
- Connect left side sensor wiring to this new sensor.
- During road test (engine must be under load and cannot be tested in Shop), swap to opposite side detonation sensor wiring to determine which of the two detonation sensors may be malfunctioning.
- NOTE: Two detonation sensors must be plugged in at all times during this test, a known good test sensor and either of the two original detonation sensors. The ignition switch must be turned off after each test period.
- Replace malfunctioning detonation sensor(s) as determined during the road test.
- If both sensors have tested good:
- Reverify all wiring connections
- Test using a new ignition ECU, P/N 5945.29
Six Flash Code:
- Check for signs of corrosion on the terminals of the relays located above the fuse box. Repair as outlined in Service Bulletin No. 273.
- Check condition of spark plugs and replace if necessary (only use Bosch HR6DS spark plugs, P/N 5961.61).
- Check that the ignition amplifier module and coil wires are in the proper location:
Amplifier Module Connector:
Pin 1 = Wire no. 3 to minus (-) side of coil Pin 2 = Wire no. M3 Pin 3 = Open Pin 4 = Wire no. 2B to plus (+) side of coil Pin 5 = Wire no. 139 bridged to pin 6 Pin 6 = Wires nos. 138 and 139
- Re-route the high tension lead for No. 1 spark plug around the outside of the power steering fluid reservoir and the oil filler on the left hand cylinder bank. Shape and fit a radio support bracket or equivalent to the power steering reservoir, as illustrated, and position the No. 1 cylinder sensor between the reservoir and the oil filler, with its harness being secured to the reservoir support bracket.
- Should the symptoms still persist, there may be a short or open circuit in the No. 1 cylinder sensor wiring harness, in which case a continuity check should be carried out at the terminals of the ignition ECU multipin connector. The ECU multipin connector must be disconnected for the following checks:
18-19 should be less than 1 ohm
18-21 should be open circuit, reading infinity
This check should be carried out with the No. 1 cylinder sensor connected. Should an incorrect reading be obtained, disconnect the No. 1 cylinder sensor and bridge the red and black wires at the rear of the connector. Then repeat the tests. If the correct readings are now obtained, replace the No. 1 cylinder sensor (P/N 5967.C1).
- If condition persists, test using a new ignition ECU, P/N 5945.29
WARRANTY INFORMATION:
Warranty coverage will be limited to the new vehicle limited warranty period, depending on the model year of the vehicle involved.
Warranty claim preparation and submission procedures should be completed in the normal manner as outlined in our Warranty Procedure manual.