Engine Controls - Ignition Discharge Module Diagnostics
TECHNICAL SERVICE BULLETINBulletin Nbr: 248-2474
Date: June 2004
Market: US/CA
New fault diagnosis for ignition discharge module, Trionic 7
Figure 1
Cars affected
Saab 9-5 M00- with Trionic 7 engine management system
(In 9-5, M00, only cars with engine option B235 are affected)
Background
New T7 software makes it possible to diagnose the ignition discharge module more accurately than before as it detects lack of sparks and improper combinations of knock and combustion signals.
The new software is available via SPS/TIS2000 and was introduced into production (9-5 M03) from VIN 33041133.
^ This TSB is to be followed when it is likely that the ignition discharge module is faulty. Ex:
- in the event of misfiring
- if the engine does not start and a fault in the ignition discharge module is suspected, e.g. if the discharge module is burnt or misfire DTCs are detected.
^ Diagnostics is to be carried out as the first step of fault diagnosis for the aforementioned fault regardless of the order in WIS.
^ Diagnostics is to be carried out and evaluated before the ignition discharge module is replaced even if it is obviously defective. "IDM Check Code" and "Failure Status" are to be included in the warranty report.
"IDM Check Code" and "Failure Status" that are read from Tech2 must be included with the claim.
Note that these values are deleted when DTCs are cleared!
Procedure
Note
In order to carry out this work the following is required:
- Tech2 version 108.000 or later
- TIS2OOO edition 2003-3 Update 4 or later
- Engine temperature must exceed 15°C (59°F)
The temperature limit is set in order that the diagnosis is reliable. In order to raise the temperature and so enable the diagnosis to be run on cars which do not start and which have lower engine temperature, a working discharge module can be temporarily installed. The diagnosis must then be run with the defective discharge module.
Fault diagnosis, extended ignition discharge module diagnostics
1. Contact T7 with Tech2, read and make a note of DTCs for possible later use.
2. Check if any of the following diagnostic trouble codes have been detected:
P0340, P1312, P1313, P1324 or P1334. These diagnostic trouble codes can be generated following repeated cold starts without the opportunity for the engine to be warmed up, depending on the carbon coating on the spark plugs. Carbon results in incorrect combustion signals and can prevent the ignition from being synchronized. However, the generation of these diagnostic trouble codes during normal driving is most often due to a fault in the ignition discharge module.
2.a. Replace ignition discharge module.
2.b. Clear the diagnostic trouble codes with Tech2 and continue with step 3.
3. Select "Ignition Discharge Module Diagnose" from the "Diagnostic Trouble Codes (DTC)" menu in Tech2.
- If the extended diagnostic function is not available in the software, a message will be displayed explaining that the function is not supported. SPS program T7 and restart diagnostics from step 3.
- If the diagnostics are available a value/code for "Current Status", "Failure Status"and "IDM Check Code" will be displayed. Information explaining "Current Status" in plain text will also be displayed in Tech2.
4. If a code for "Failure Status" is displayed before the engine is started:
4.a. Note down "Failure Status" and "IDM Check Code". Repair or replace according to the table.
4.b. Clear DTCs with Tech2 after work is completed.
5. If no code for "Failure Status" is displayed before the engine is started:
5.a. Complete the diagnosis according to the instructions in the "Information Text" field on the Tech2 screen.
5.b. If a code for "Failure Status" is displayed during starter motor cranking, during the synchronization phase or after the key has been released back to ON following a start attempt, note down the "Failure Status" and "IDM Check Code". Repair or replace according to the table below.
5.c. Clear DTCs with Tech2 after work is completed.
6. If the diagnostics fail to detect a fault:
Continue fault diagnosis in subsystems other than the ignition system. Use the previously read DTCs if available.
Note
If the ignition discharge module is replaced due to type P diagnostic trouble codes related to incorrect combustion signals or synchronization errors in accordance with step 2 then the fault is probably rectified. Note down all type P diagnostic trouble codes which lead to the decision to replace the ignition discharge module.
Note
Further information on diagnostic trouble codes P0340, P1312, P1313, P1324 and P1334.
The spark plugs are the control module's sensors for combustion data. Repeated cold starts without the opportunity for the engine to be warmed up can cause a carbon coating on the spark plugs. This can result in type P diagnostic trouble codes of the same type as an internal fault in the ignition discharge module. In the event of uncertainty over the reason for such a type P diagnostic trouble code, DTC Freeze Frame can be used. It has become evident that these diagnostic trouble codes are most often generated with an engine at operating temperature (above 80°C (176°F)) if the cause is an internal fault in the ignition discharge module. Carbon related diagnostic trouble codes are generated at the start of the engine's warming-up phase. It is difficult to check for carbon on the spark plugs in the workshop by means of visual inspection alone of the spark plugs as the carbon easily burns away after the engine has been warmed up. For this reason, and until further notice, the ignition discharge module must be replaced when these diagnostic trouble codes are generated.
Description of Tech2 status information "Current Status"
This value indicates the current stage of the diagnostic procedure. If the value is 130 or below, no fault has been detected on the ignition discharge module thus far. The following P-DTCs can block diagnostics: P0171, P0172, P0336, P0337, P1171, P1172, P1181, P1182, P1310, P1320 and P1460. Diagnostics can also be blocked if coolant temperature is below 15°C (59°F ). If one of the aforementioned DTCs has been detected, follow standard fault diagnosis.
"Failure Status"
If "Current Status" indicates a value of 131 or higher then a fault has been detected that is also displayed as "Failure Status". With some exceptions, "Failure Status" is then stored during 40 warming-up cycles. The function is similar to fault handling for normal type P diagnostic trouble codes. Failure Status is deleted when diagnostic trouble codes are cleared with Tech2.
"IDM Check Code"
A code is displayed here if a fault has been detected. A code for "Failure Status" is also displayed. "IDM Check Code" contains data from the fault occurrence and car identification. "IDM Check Code" is deleted when diagnostic trouble codes are cleared with Tech2. "IDM Check Code" and "Failure Status" must be included when submitting a claim for the ignition discharge module.
"Failure Status", cars with 4-cyl engine
"Information Text"
In this field, Tech2 displays "Current Status" in plain text.
"Current Status"
"Failure Status", cars with V6 engine
Standard times/Warranty information
In the case of customer complaint and if the car is within the warranty period, include "Failure Status" and "IDM Check Code" and use the following information to fill out the claim:
SPS programming has been completed
Failed object: 34041
Fault/reason code: 08
Location code: 09
Repair/Action code: 08
Time: 0.7 hrs.
SPS programming has not been completed
Failed object: 34041
Fault/reason code: 08
Location code: 09
Repair/Action code: 08
Time: 0.2 hrs.
For spark plug replacement:
Add Failed Object for 4-cyl: 34411
Time: 0.3 hrs.
Add Failed Object for V6: 34411
Time: 0.5 hr