Allison
Allison 3000 & 4000 Gen 4 Fault Code: P0883 TCM Power Input Signal High
Posted by PerDiezel Solutions on
DIAGNOSTIC RESPONSE:None CIRCUIT DESCRIPTION:The Transmission Control Module (TCM) requires direct battery voltage input to operate. This test monitors for high battery voltage to the TCM on terminals 10 and 70. NOTE: The TCM battery power signal must be provided through a 10a or 15A fuse, or a manually-reset circuit breaker. CONDITIONS FOR RUNNING THE DTC:1. Engine speed above 450 rpm for at least 30 seconds.2. DTC test runs at 0.025 second intervals. CONDITIONS FOR SETTING THE DTC:DTC P0883 sets:1. For a 12V TCM, battery voltage exceeds 18 volts after engine runtime over 1.5 seconds.2. For a 24V TCM, battery voltage...
Allison 3000 & 4000 Gen 4 Fault Code: P088A Transmission Filter Maintenance Alert
Posted by PerDiezel Solutions on
DIAGNOSTIC RESPONSE:None CIRCUIT DESCRIPTION:The Filter Life Monitor (FM) feature alerts the driver when a filter change is needed by illuminating the SERVICE TRANS indicator (wrench icon display). FM also activates any OEM-provided SERVICE TRANS indicator or datalink message center display (when integrated to receive the message). If the filter is detected as restricted, the wrench icon in the selector flashes ON and OFF for approximately 2 minutes the first time D (Drive) is selected after each engine start. Also, DTC P088A becomes active concurrently with these other visible filter maintenance alerts. This DTC monitors the electrical state of the PS2...
Allison 3000 & 4000 Gen 4 Fault Code: P088B Transmission Filter Maintenance Required
Posted by PerDiezel Solutions on
DIAGNOSTIC RESPONSE:None CIRCUIT DESCRIPTION:The Filter Life Monitor (FM) feature alerts the driver when a filter change is needed by illuminating the SERVICE TRANS indicator (wrench icon in keypad or lever shift selector display). FM also activates any OEM-provided SERVICE TRANS indicator or datalink message center display (when integrated to receive the message). If the filter is detected as restricted, the wrench icon in the selector flashes ON and OFF for approximately 2 minutes the first time D (Drive) is selected after each engine start. Also, DTC P088A becomes active concurrently with these other visible filter maintenance alerts. This DTC monitors...
Allison 3000 & 4000 Gen 4 Fault Code: P088B Transmission Filter Very Deteriorated (Expired)
Posted by PerDiezel Solutions on
DIAGNOSTIC RESPONSE:None CIRCUIT DESCRIPTION:The Filter Life Monitor (FM) feature alerts the driver when a filter change is needed by illuminating the SERVICE TRANS indicator (wrench icon in an OEM 4th Generation with Prognostics keypad or lever shift selector display). FM also activates any OEM-provided SERVICE TRANS indicator or datalink message center display (when integrated to receive the message). If the filter is detected as restricted, the wrench icon in the selector flashes ON and OFF for approximately 2 minutes the first time D (Drive) is selected after each engine start. Also, DTC P088A becomes active concurrently with these other visible...
Allison 3000 & 4000 Gen 4 Fault Code: P0894 Transmission Component Slipping
Posted by PerDiezel Solutions on
DIAGNOSTIC RESPONSE:DNS, Lock in first CIRCUIT DESCRIPTION:This DTC test detects if the expected turbine speed pull-down did not occur or the expected gear ratio was not attained during the TCM range attained verification check. CONDITIONS FOR RUNNING THE DTC:1. Hydraulic system is pressurized.2. Hydraulic default condition not present.3. Output speed is above 60 rpm (20 rpm for Reverse 2 (R2)).4. Engine initialization or shutdown is not in process.5. Engine speed above 800 rpm.6. Shifting complete.7. Range attained is not Neutral (N).8. Reverse-to-Neutral shift not in process.9. For fire truck applications, pump is not pumping. CONDITIONS FOR SETTING THE DTC:DTC P0894...